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2022 Volume 38 Issue 11
2022, 38(11): 2113-2126
doi: 10.11862/CJIC.2022.227
Abstract:
Since the first discovery of nitrogen - doped carbon nanotubes with outstanding catalytic performance toward the oxygen reduction reaction, carbon-based metal-free materials hold great potential as promising alternatives to noble metal-based electrocatalysts prevailingly used in common energy technologies. In addition to the positive role of dopants, the ubiquitous intrinsic defects in the carbon skeleton are also important factors that affect the physical and chemical properties of carbon materials. Specifically, the carbon defects can induce localized charge and/or spin density redistribution and optimize the adsorption and/or desorption behaviors of key species, thereby improving the catalytic activity of adjoining carbon atoms. Rational design and creation of well-defined defects in carbon skeleton have recently become a crucial research frontier of carbon-based metal-free electrocatalysts. In this paper, we present an overview of recent advances in the intrinsic defects of carbon materials for electrocatalytic applications. Special focus is placed on three types of intrinsic defects, including edges, vacancies/holes, and topological defects. The fundamental features of these defects are first discussed, followed by summarizing the preparation and characterization methodology of such defects. According to both experimental and theoretical studies, the underlying correlations between the electronic structure and the electrocatalytic performance of these differentlyconfigured carbon defects are systematically elaborated. Finally, facing challenges and future perspectives on the intrinsic carbon defects for electrocatalysis are also provided.
Since the first discovery of nitrogen - doped carbon nanotubes with outstanding catalytic performance toward the oxygen reduction reaction, carbon-based metal-free materials hold great potential as promising alternatives to noble metal-based electrocatalysts prevailingly used in common energy technologies. In addition to the positive role of dopants, the ubiquitous intrinsic defects in the carbon skeleton are also important factors that affect the physical and chemical properties of carbon materials. Specifically, the carbon defects can induce localized charge and/or spin density redistribution and optimize the adsorption and/or desorption behaviors of key species, thereby improving the catalytic activity of adjoining carbon atoms. Rational design and creation of well-defined defects in carbon skeleton have recently become a crucial research frontier of carbon-based metal-free electrocatalysts. In this paper, we present an overview of recent advances in the intrinsic defects of carbon materials for electrocatalytic applications. Special focus is placed on three types of intrinsic defects, including edges, vacancies/holes, and topological defects. The fundamental features of these defects are first discussed, followed by summarizing the preparation and characterization methodology of such defects. According to both experimental and theoretical studies, the underlying correlations between the electronic structure and the electrocatalytic performance of these differentlyconfigured carbon defects are systematically elaborated. Finally, facing challenges and future perspectives on the intrinsic carbon defects for electrocatalysis are also provided.
2022, 38(11): 2127-2142
doi: 10.11862/CJIC.2022.222
Abstract:
All-solid-state batteries (ASSBs) are commonly regarded as prospective electrochemical energy storage devices, which can overcome the drawbacks of conventional liquid electrolyte batteries, including electrolyte leak- age, low stability, flammability, and limited energy density. In the research of ASSBs, developing solid electrolyte (SE) with high ionic conductivity and a wide electrochemical stability window is critical to the development of ASSBs with high energy and power density. Recently, hydroborate- based SEs have received extensive attention as they offer a comprehensive combination of super-ionic conductivity at high temperature, high thermal stability, and low density. Among these, one of the most promising materials is the alkali-metal salts of closo-decahydrodecaborate (B10H102-). Since B10H102- was first discovered in 1959, its synthetic methods and application have been widely stud- ied. After years of research, mature methods for the preparation of the B10H102- compounds have been developed, which can satisfy the supply demands in the laboratory. As a multifunctional material, decahydrodecaborate has been intensively studied for several applications. In particular, as a promising candidate for SE, the sodium and lithium closo-decahydrodecaborates M2B10H10 (M=Na, Li) have been proved to own excellent ionic conductivity as well as high thermal and chemical stability. To further improve the electrochemical performances of B10H102--based elec- trolytes at room temperature, many modification strategies have been explored and implemented, including halogen substitution, carboranate, mechanical ball milling, complex anion alloying, and dimerization. This review mainly describes the progress of preparation and application in the solid electrolyte of B10H102-, summarizes the modification strategies of better - performance B10H102- based SE, and also puts forward prospects for the future development of B10H102- as SE in ASSBs.
All-solid-state batteries (ASSBs) are commonly regarded as prospective electrochemical energy storage devices, which can overcome the drawbacks of conventional liquid electrolyte batteries, including electrolyte leak- age, low stability, flammability, and limited energy density. In the research of ASSBs, developing solid electrolyte (SE) with high ionic conductivity and a wide electrochemical stability window is critical to the development of ASSBs with high energy and power density. Recently, hydroborate- based SEs have received extensive attention as they offer a comprehensive combination of super-ionic conductivity at high temperature, high thermal stability, and low density. Among these, one of the most promising materials is the alkali-metal salts of closo-decahydrodecaborate (B10H102-). Since B10H102- was first discovered in 1959, its synthetic methods and application have been widely stud- ied. After years of research, mature methods for the preparation of the B10H102- compounds have been developed, which can satisfy the supply demands in the laboratory. As a multifunctional material, decahydrodecaborate has been intensively studied for several applications. In particular, as a promising candidate for SE, the sodium and lithium closo-decahydrodecaborates M2B10H10 (M=Na, Li) have been proved to own excellent ionic conductivity as well as high thermal and chemical stability. To further improve the electrochemical performances of B10H102--based elec- trolytes at room temperature, many modification strategies have been explored and implemented, including halogen substitution, carboranate, mechanical ball milling, complex anion alloying, and dimerization. This review mainly describes the progress of preparation and application in the solid electrolyte of B10H102-, summarizes the modification strategies of better - performance B10H102- based SE, and also puts forward prospects for the future development of B10H102- as SE in ASSBs.
2022, 38(11): 2143-2153
doi: 10.11862/CJIC.2022.229
Abstract:
Taking advantage of a basic ligand (BPCH=2, 6 -bis(4-pyridyl methylidene)cyclohexanone) and three acid ligands (H2TP=terephthalic acid, H2IP=isophthalic acid, H3TMA=1, 3, 5 - benzenetricarboxylic acid), seven metal - organic frameworks (MOFs) 1-7 have been achieved by using this acid - base mixed - ligand synthetic strategy. These complexes were characterized by single-crystal X-ray diffraction, IR spec- tra, powder X-ray diffraction, and thermogravimetric analysis. Diverse 3D structural characters of MOFs 1-3 or 2D structural characters of MOFs 4-7 have been observed. The fluorescence properties of these complexes have been explored, indicating that they had selectivity towards Fe3+ ions. Several complexes had shown certain performance for adsorbing dye molecules.
Taking advantage of a basic ligand (BPCH=2, 6 -bis(4-pyridyl methylidene)cyclohexanone) and three acid ligands (H2TP=terephthalic acid, H2IP=isophthalic acid, H3TMA=1, 3, 5 - benzenetricarboxylic acid), seven metal - organic frameworks (MOFs) 1-7 have been achieved by using this acid - base mixed - ligand synthetic strategy. These complexes were characterized by single-crystal X-ray diffraction, IR spec- tra, powder X-ray diffraction, and thermogravimetric analysis. Diverse 3D structural characters of MOFs 1-3 or 2D structural characters of MOFs 4-7 have been observed. The fluorescence properties of these complexes have been explored, indicating that they had selectivity towards Fe3+ ions. Several complexes had shown certain performance for adsorbing dye molecules.
2022, 38(11): 2238-2248
doi: 10.11862/CJIC.2022.223
Abstract:
In this study, a Ni(Ⅱ)⁃doped hierarchical porous metal⁃organic framework (HP⁃Ni⁃Cu⁃BTC, H3BTC= benzene⁃1, 3, 5⁃tricarboxylic acid) hierarchical porous metal⁃organic framework was successfully prepared, and applied as an adsorbent for the removal of tetracycline (TC). The Ni(Ⅱ) doping and hierarchical porosity structure significantly increased the adsorption capacity of TC, which was 3.28 times that of microporous Cu⁃BTC. The adsorption kinetics and adsorption isotherm studies demonstrated that chemisorption dominated the adsorption reaction and that the adsorption of TC on HP⁃Ni⁃Cu⁃BTC proceeds through multilayer adsorption on a non⁃homogeneous adsorbent surface. Moreover, in the cycling experiments, there was still 71.45% adsorption efficiency after four times of reuse, indicating that HP⁃Ni⁃Cu⁃BTC had good reusability.
In this study, a Ni(Ⅱ)⁃doped hierarchical porous metal⁃organic framework (HP⁃Ni⁃Cu⁃BTC, H3BTC= benzene⁃1, 3, 5⁃tricarboxylic acid) hierarchical porous metal⁃organic framework was successfully prepared, and applied as an adsorbent for the removal of tetracycline (TC). The Ni(Ⅱ) doping and hierarchical porosity structure significantly increased the adsorption capacity of TC, which was 3.28 times that of microporous Cu⁃BTC. The adsorption kinetics and adsorption isotherm studies demonstrated that chemisorption dominated the adsorption reaction and that the adsorption of TC on HP⁃Ni⁃Cu⁃BTC proceeds through multilayer adsorption on a non⁃homogeneous adsorbent surface. Moreover, in the cycling experiments, there was still 71.45% adsorption efficiency after four times of reuse, indicating that HP⁃Ni⁃Cu⁃BTC had good reusability.
2022, 38(11): 2249-2258
doi: 10.11862/CJIC.2022.220
Abstract:
Two new metal⁃organic coordination polymers [Cu4(4⁃nph)(L)6]n (1) and {[Cu2(bda)2(bib)2(H2O)4]·4H2O}n (2) were prepared under hydrothermal conditions by employing 4⁃nitrophthalic acid (4⁃H2nph)/2, 2'⁃bipyridine⁃4, 4'⁃dicarboxylic acid (H2bda) as the primary ligand and 3⁃(2⁃pyridyl)pyrazole (HL)/1, 4⁃bis(imidazol⁃1⁃yl)⁃butane (bib) as the ancillary ligand. They were characterized by elemental analysis, infrared spectroscopy, thermogravimetry, X⁃ray single crystal diffractometer, and X⁃ray powder diffractometer. The results show that complex 1 belongs to monoclinic system, C2/c space group with cell parameters: a=1.956 16(8) nm, b=1.290 68(8) nm, c=2.160 34(12) nm, β=97.073(2)°, V=5.412 9(5) nm3, Z=4; and complex 2 crystallizes in triclinic system, P1 space group with cell parameters: a=0.962 22(15) nm, b=1.102 90(17) nm, c=1.404 3(2) nm, α=72.752(4)°, β=79.271(4)°, γ=67.065(3)°, V=1.306 6(4) nm3, Z=1. In complex 1, the carboxyl ligand 4⁃nph2- bridges the metal centers via monodentate modes. The metal centers are coordinated by 4⁃nph2- to form a 1D structure. In complex 2, the flexible bib linked metal centers to form a dinuclear structure with a 26⁃member ring. In addition, the quantum⁃chemical calculations were accomplished on"molecular fragments"extracted from the crystal structure of 1 using the PBE0/LANL2DZ method in the Gaussian 16 program. The calculation values denoted the distinct covalent interaction between the coordinated atoms and Cu(Ⅱ) ion.
Two new metal⁃organic coordination polymers [Cu4(4⁃nph)(L)6]n (1) and {[Cu2(bda)2(bib)2(H2O)4]·4H2O}n (2) were prepared under hydrothermal conditions by employing 4⁃nitrophthalic acid (4⁃H2nph)/2, 2'⁃bipyridine⁃4, 4'⁃dicarboxylic acid (H2bda) as the primary ligand and 3⁃(2⁃pyridyl)pyrazole (HL)/1, 4⁃bis(imidazol⁃1⁃yl)⁃butane (bib) as the ancillary ligand. They were characterized by elemental analysis, infrared spectroscopy, thermogravimetry, X⁃ray single crystal diffractometer, and X⁃ray powder diffractometer. The results show that complex 1 belongs to monoclinic system, C2/c space group with cell parameters: a=1.956 16(8) nm, b=1.290 68(8) nm, c=2.160 34(12) nm, β=97.073(2)°, V=5.412 9(5) nm3, Z=4; and complex 2 crystallizes in triclinic system, P1 space group with cell parameters: a=0.962 22(15) nm, b=1.102 90(17) nm, c=1.404 3(2) nm, α=72.752(4)°, β=79.271(4)°, γ=67.065(3)°, V=1.306 6(4) nm3, Z=1. In complex 1, the carboxyl ligand 4⁃nph2- bridges the metal centers via monodentate modes. The metal centers are coordinated by 4⁃nph2- to form a 1D structure. In complex 2, the flexible bib linked metal centers to form a dinuclear structure with a 26⁃member ring. In addition, the quantum⁃chemical calculations were accomplished on"molecular fragments"extracted from the crystal structure of 1 using the PBE0/LANL2DZ method in the Gaussian 16 program. The calculation values denoted the distinct covalent interaction between the coordinated atoms and Cu(Ⅱ) ion.
2022, 38(11): 2259-2266
doi: 10.11862/CJIC.2022.226
Abstract:
We herein report the synthetic, structural, and magnetic studies on two 2D isomorphous complexes, {(NH2(CH3)2)2[M(L)]}n (M=Fe (1), Co (2), H4L=1, 1'-(1, 4-phenylenebis(methylene))bis(1H-pyrazole -3, 5-dicarboxylic acid)). From single crystal X-ray crystallography, it is found that the complexes crystallized in the same space group monoclinic P21 / n and have six - coordinate octahedron structures. The framework features anionic having a -2 charge, and the electroneutrality is achieved by the incorporation of the protonated dimethylamine by hydrolysis of DMF in the voids of the net. In the two polymers, each ligand bridges two metal(Ⅱ) ions through cheating N, O atoms of the pyrazole ring and monodentate O atoms of the same pyrazole ring, forming ⋯M-L-M-L⋯ chains and the 1D chains intersect to form an infinite 2D network which contains nearly square M4L4 units. Magnetic susceptibility measurements indicate the presence of antiferromagnetic properties in complexes 1 and 2.
We herein report the synthetic, structural, and magnetic studies on two 2D isomorphous complexes, {(NH2(CH3)2)2[M(L)]}n (M=Fe (1), Co (2), H4L=1, 1'-(1, 4-phenylenebis(methylene))bis(1H-pyrazole -3, 5-dicarboxylic acid)). From single crystal X-ray crystallography, it is found that the complexes crystallized in the same space group monoclinic P21 / n and have six - coordinate octahedron structures. The framework features anionic having a -2 charge, and the electroneutrality is achieved by the incorporation of the protonated dimethylamine by hydrolysis of DMF in the voids of the net. In the two polymers, each ligand bridges two metal(Ⅱ) ions through cheating N, O atoms of the pyrazole ring and monodentate O atoms of the same pyrazole ring, forming ⋯M-L-M-L⋯ chains and the 1D chains intersect to form an infinite 2D network which contains nearly square M4L4 units. Magnetic susceptibility measurements indicate the presence of antiferromagnetic properties in complexes 1 and 2.
2022, 38(11): 2267-2274
doi: 10.11862/CJIC.2022.216
Abstract:
An interesting polynuclear Gd(Ⅲ)-based cluster with the molecular formula [Gd4(CH3COO)6(H3L)2]· 2CH3OH (1) based on a polydentate ligand (H6L=1, 3-bis(tris(hydroxymethyl)methylamino)propane) has been successfully synthesized via the solvothermal method. The structure, magnetic property, and bacteriostatic activity of cluster 1 have been systematically studied. Structural analysis shows that there are two distinct coordination environments of central Gd(Ⅲ) ions and cluster 1 mainly contains a butterfly Gd4 core. The magnetic study reveals that antiferromagnetic interaction exists in cluster 1. More importantly, cluster 1 displayed significant cryogenic magnetic refrigeration property with-ΔSm=40.6 J·kg-1·K-1 at T=2.0 K and ΔH=7.0 T. Moreover, cluster 1 possessed antibacterial activity on five common bacteria, among which the antibacterial effect on Micrococcus luteus was the best.
An interesting polynuclear Gd(Ⅲ)-based cluster with the molecular formula [Gd4(CH3COO)6(H3L)2]· 2CH3OH (1) based on a polydentate ligand (H6L=1, 3-bis(tris(hydroxymethyl)methylamino)propane) has been successfully synthesized via the solvothermal method. The structure, magnetic property, and bacteriostatic activity of cluster 1 have been systematically studied. Structural analysis shows that there are two distinct coordination environments of central Gd(Ⅲ) ions and cluster 1 mainly contains a butterfly Gd4 core. The magnetic study reveals that antiferromagnetic interaction exists in cluster 1. More importantly, cluster 1 displayed significant cryogenic magnetic refrigeration property with-ΔSm=40.6 J·kg-1·K-1 at T=2.0 K and ΔH=7.0 T. Moreover, cluster 1 possessed antibacterial activity on five common bacteria, among which the antibacterial effect on Micrococcus luteus was the best.
2022, 38(11): 2275-2282
doi: 10.11862/CJIC.2022.212
Abstract:
The LiBaPO4: Eu3+ phosphors were prepared by the sol-gel method, and the structure and luminescence properties of the phosphors were characterized by thermogravimetric-differential thermal analysis (TG-DTA), Fourier transformation infrared (IR) spectrum, X-ray diffraction (XRD), transmission electron microscope (TEM), and fluorescence spectrum. TG-DTA results showed that the LiBaPO4 phase can be formed upon 700 ℃. IR spectra confirmed the existence of PO43- ions. XRD results showed that temperature change can cause different degrees of cleavage of the diffraction peaks. Eu3+ doping concentration can affect the crystal phase of the sample, and the samples with a lower doping concentration appeared impurity, as the doping concentration increased, the sample was a pure phase of hexagonal crystals LiBaPO4. TEM showed that the material particles agglomerated to a certain extent with the increase in concentration. The fluorescence measurement results showed that LiBaPO4: Eu3+ had different optimal excitation wavelengths at different annealing temperatures and its dominant energy level transition is due to the differences in the crystal structure and coordination environment of the activator at different temperatures, and the concentration quenching caused by Eu3+ also varied. CIE calculation results showed that the color purity of the sample gradually improved with the increase of annealing temperature. LiBaPO4: Eu3+ can be effectively excited by 394 nm long-wave ultraviolet light, indicating its potential application in the field of white light-emitting diodes.
The LiBaPO4: Eu3+ phosphors were prepared by the sol-gel method, and the structure and luminescence properties of the phosphors were characterized by thermogravimetric-differential thermal analysis (TG-DTA), Fourier transformation infrared (IR) spectrum, X-ray diffraction (XRD), transmission electron microscope (TEM), and fluorescence spectrum. TG-DTA results showed that the LiBaPO4 phase can be formed upon 700 ℃. IR spectra confirmed the existence of PO43- ions. XRD results showed that temperature change can cause different degrees of cleavage of the diffraction peaks. Eu3+ doping concentration can affect the crystal phase of the sample, and the samples with a lower doping concentration appeared impurity, as the doping concentration increased, the sample was a pure phase of hexagonal crystals LiBaPO4. TEM showed that the material particles agglomerated to a certain extent with the increase in concentration. The fluorescence measurement results showed that LiBaPO4: Eu3+ had different optimal excitation wavelengths at different annealing temperatures and its dominant energy level transition is due to the differences in the crystal structure and coordination environment of the activator at different temperatures, and the concentration quenching caused by Eu3+ also varied. CIE calculation results showed that the color purity of the sample gradually improved with the increase of annealing temperature. LiBaPO4: Eu3+ can be effectively excited by 394 nm long-wave ultraviolet light, indicating its potential application in the field of white light-emitting diodes.
2022, 38(11): 2283-2290
doi: 10.11862/CJIC.2022.235
Abstract:
A mononuclear Fe(Ⅲ) complex, [FeⅢ(bzimpy-1H)2]Cl (1) was prepared by the reaction of a tridentate ligand 2, 6-bis(benzimidazol-2-yl)pyridine (bzimpy), where bzimpy-1H is the product of bzimpy after removing one proton, and its structure and magnetic properties were characterized in detail. The single crystal structure analysis shows that the Fe3+ center features a rare distorted octahedral N6 coordination environment for the complex, and the 3D supramolecular structure is constructed by N—H⋯Cl hydrogen bonding between the adjacent cation complex units and counterbalance chloride ions. The complex showed hysteretic spin-crossover (SCO) behavior above room temperature as evidenced by combined magnetic investigations and differential scanning calorimetry measurements (T1/2↑=345 K, T1/2 ↓=330 K). In addition, the light-induced excited spin state trapping (LIESST) effect was also observed in the complex. The magnetism-structure relationship shows that the N—H⋯Cl hydrogen bonding plays an important role in the bistable SCO behavior of the complex.
A mononuclear Fe(Ⅲ) complex, [FeⅢ(bzimpy-1H)2]Cl (1) was prepared by the reaction of a tridentate ligand 2, 6-bis(benzimidazol-2-yl)pyridine (bzimpy), where bzimpy-1H is the product of bzimpy after removing one proton, and its structure and magnetic properties were characterized in detail. The single crystal structure analysis shows that the Fe3+ center features a rare distorted octahedral N6 coordination environment for the complex, and the 3D supramolecular structure is constructed by N—H⋯Cl hydrogen bonding between the adjacent cation complex units and counterbalance chloride ions. The complex showed hysteretic spin-crossover (SCO) behavior above room temperature as evidenced by combined magnetic investigations and differential scanning calorimetry measurements (T1/2↑=345 K, T1/2 ↓=330 K). In addition, the light-induced excited spin state trapping (LIESST) effect was also observed in the complex. The magnetism-structure relationship shows that the N—H⋯Cl hydrogen bonding plays an important role in the bistable SCO behavior of the complex.
2022, 38(11): 2291-2298
doi: 10.11862/CJIC.2022.236
Abstract:
Two coordination polymers, {[Hg2(L1) (μ2-I)2I2] ·2DMF·H2O}n (1) and {[Hg(L2)I2] ·H2O}n (2), have been designed and synthesized from two dipyridylamide ligands (L1 and L2) with mercury(Ⅱ) iodide, respectively. X-ray crystallographic analyses show that both the two complexes exist as 1D zig-zag chain structures but exhibit different configurations by slightly adjusted 3-and 4-pyridyl nitrogen atoms from the ligands. Each Hg(Ⅱ) center of the two complexes is four-coordinated with distorted tetrahedral geometry. In complex 1, the Hg(Ⅱ) center is coordinated by one 3-pyridyl nitrogen atom and three iodide anions in a 1∶2 molar ratio of L1 and mercury iodide. In complex 2, the Hg(Ⅱ) center is coordinated by two 4-pyridyl nitrogen atoms and two iodide anions in a 1∶1 molar ratio of L2 and mercury iodide. In addition, the thermal stabilities, luminescence properties, together with vapor adsorption properties of the two complexes were investigated.
Two coordination polymers, {[Hg2(L1) (μ2-I)2I2] ·2DMF·H2O}n (1) and {[Hg(L2)I2] ·H2O}n (2), have been designed and synthesized from two dipyridylamide ligands (L1 and L2) with mercury(Ⅱ) iodide, respectively. X-ray crystallographic analyses show that both the two complexes exist as 1D zig-zag chain structures but exhibit different configurations by slightly adjusted 3-and 4-pyridyl nitrogen atoms from the ligands. Each Hg(Ⅱ) center of the two complexes is four-coordinated with distorted tetrahedral geometry. In complex 1, the Hg(Ⅱ) center is coordinated by one 3-pyridyl nitrogen atom and three iodide anions in a 1∶2 molar ratio of L1 and mercury iodide. In complex 2, the Hg(Ⅱ) center is coordinated by two 4-pyridyl nitrogen atoms and two iodide anions in a 1∶1 molar ratio of L2 and mercury iodide. In addition, the thermal stabilities, luminescence properties, together with vapor adsorption properties of the two complexes were investigated.
2022, 38(11): 2299-2307
doi: 10.11862/CJIC.2022.205
Abstract:
[Ti2(μ2-O)(Pycox)2(OiPr)4] (1) was solvothermally synthesized by the reaction of 2-pyridinecarbaldehyde oxime (Hpycox) and Ti(OiPr)4 in a simple and general approach. Interestingly, by analyzing the structure of 1, diphenylphosphinic acid and phenylphosphonic acid were selected respectively to regulate the structure of 1, and [Ti3(μ2-O)2(Pycox)2(Ph2PO2)2(OiPr)4] (2) and [Ti6(μ2-O)2(μ3-O)2(Pycox) 2 (PhPO3)4(OiPr) 6]·2CH3CN (3) were successfully obtained. Moreover, their light absorption behaviors, band gaps, and photocurrent responses were also investigated. The band gaps of complexes 1-3 were 2.89, 3.00, and 2.87 eV, respectively. Among the three complexes, complex 2 exhibited the largest photocurrent density with the value of 0.10 μA·cm-2.
[Ti2(μ2-O)(Pycox)2(OiPr)4] (1) was solvothermally synthesized by the reaction of 2-pyridinecarbaldehyde oxime (Hpycox) and Ti(OiPr)4 in a simple and general approach. Interestingly, by analyzing the structure of 1, diphenylphosphinic acid and phenylphosphonic acid were selected respectively to regulate the structure of 1, and [Ti3(μ2-O)2(Pycox)2(Ph2PO2)2(OiPr)4] (2) and [Ti6(μ2-O)2(μ3-O)2(Pycox) 2 (PhPO3)4(OiPr) 6]·2CH3CN (3) were successfully obtained. Moreover, their light absorption behaviors, band gaps, and photocurrent responses were also investigated. The band gaps of complexes 1-3 were 2.89, 3.00, and 2.87 eV, respectively. Among the three complexes, complex 2 exhibited the largest photocurrent density with the value of 0.10 μA·cm-2.
2022, 38(11): 2308-2320
doi: 10.11862/CJIC.2022.231
Abstract:
A novel NiMoO4 NWs@ZnCo MOF (NWs=nanowires) was successfully synthesized by making a layer of ZnCo metal-organic framework (MOF) nanocrystals in situ grown on the NiMoO4 NWs by liquid phase synthesis and then it was heat-treated at 350 ℃ (named NiMoO4 NWs@ZnCo MOF(350)). It was found that the structure and morphology of the precursor were still well maintained after heat treatment, but a very small amount of Co3O4 phase appeared in ZnCo MOF, indicating that slight pyrolysis occurred. Chemical bonds C—O—Mo and a large number of oxygen vacancies generated at the phase heterointerfaces can become the source of active sites. The formation of a new Co3O4 phase also leads to a further increase in the heterophase interfaces. Furthermore, a little pyrolysis made the surface of the core-shell structure more coarse, loose, and porous, producing a higher specific surface area, faster ionic diffusion path, and better electrical conductivity. Therefore, according to the inert glassy carbon electrode test, the electrocatalyst exhibited a low overpotential of 360 mV at the current density of 10 mA·cm-2 and maintained long-term catalytic stability of 30 000 s.
A novel NiMoO4 NWs@ZnCo MOF (NWs=nanowires) was successfully synthesized by making a layer of ZnCo metal-organic framework (MOF) nanocrystals in situ grown on the NiMoO4 NWs by liquid phase synthesis and then it was heat-treated at 350 ℃ (named NiMoO4 NWs@ZnCo MOF(350)). It was found that the structure and morphology of the precursor were still well maintained after heat treatment, but a very small amount of Co3O4 phase appeared in ZnCo MOF, indicating that slight pyrolysis occurred. Chemical bonds C—O—Mo and a large number of oxygen vacancies generated at the phase heterointerfaces can become the source of active sites. The formation of a new Co3O4 phase also leads to a further increase in the heterophase interfaces. Furthermore, a little pyrolysis made the surface of the core-shell structure more coarse, loose, and porous, producing a higher specific surface area, faster ionic diffusion path, and better electrical conductivity. Therefore, according to the inert glassy carbon electrode test, the electrocatalyst exhibited a low overpotential of 360 mV at the current density of 10 mA·cm-2 and maintained long-term catalytic stability of 30 000 s.
2022, 38(11): 2154-2164
doi: 10.11862/CJIC.2022.224
Abstract:
Erbium - doped hydroxyapatite (Er - HAP) particles were prepared by the co - precipitation method. The crystal structure, surface chemical composition, and fluorescent properties of Er-HAP particles were characterized by the methods of X- ray diffraction combined with Materials Studio, scanning electron microscopy-energy dispersive spectroscopy, X - ray photoelectron spectroscopy, and fluorescence spectroscopy. The results showed that Er3+ can competitively substitute for a Ca2+ site in the crystal lattice. Under the excitation of a 340 nm light source, Er-HAP particles emitted significant fluorescence at around 419 nm (purple), 458 nm (blue), 501 nm (green), and 535 nm (green), respectively. The four corresponding luminescence bands are attributed to 4F3/2 → 4I15/2, 4F5/2 → 4I15/2, 4F7/2 →4I15/2, and 4S3/2 → 4I15/2 transition states, respectively. Further, we evaluated the biomineralization ability by analyzing the formation of an interfacial layer after Er-HAP particles were immersed in simulated body fluid. When the dopant content (molar fraction) of Er3+ was 1%, it was observed that Er-HAP particles could form the mineralized layer with plate-like structures, and Er3+ incorporation affected the biomineralization ability, whereas the biomineralization rate and osteogenic performance significantly decreased with the increasing of the dopant content of Er3+. Therefore, the stronger biomineralization ability of Er-HAP particles might be exhibited while the Er dopant content was about 1%.
Erbium - doped hydroxyapatite (Er - HAP) particles were prepared by the co - precipitation method. The crystal structure, surface chemical composition, and fluorescent properties of Er-HAP particles were characterized by the methods of X- ray diffraction combined with Materials Studio, scanning electron microscopy-energy dispersive spectroscopy, X - ray photoelectron spectroscopy, and fluorescence spectroscopy. The results showed that Er3+ can competitively substitute for a Ca2+ site in the crystal lattice. Under the excitation of a 340 nm light source, Er-HAP particles emitted significant fluorescence at around 419 nm (purple), 458 nm (blue), 501 nm (green), and 535 nm (green), respectively. The four corresponding luminescence bands are attributed to 4F3/2 → 4I15/2, 4F5/2 → 4I15/2, 4F7/2 →4I15/2, and 4S3/2 → 4I15/2 transition states, respectively. Further, we evaluated the biomineralization ability by analyzing the formation of an interfacial layer after Er-HAP particles were immersed in simulated body fluid. When the dopant content (molar fraction) of Er3+ was 1%, it was observed that Er-HAP particles could form the mineralized layer with plate-like structures, and Er3+ incorporation affected the biomineralization ability, whereas the biomineralization rate and osteogenic performance significantly decreased with the increasing of the dopant content of Er3+. Therefore, the stronger biomineralization ability of Er-HAP particles might be exhibited while the Er dopant content was about 1%.
2022, 38(11): 2165-2172
doi: 10.11862/CJIC.2022.232
Abstract:
CNTs-GNPs, hybrid support composed of carbon nanotubes (CNTs) and graphene nanoplates (GNPs) was prepared by a solid phase -liquid phase two-step mixing method. The Pd/CNTs -GNPs catalyst was prepared by depo- sition of Pd nanoparticles on composite carbon support by the ethylene glycol reduction method. The morphologies, compositions, and structures of catalysts were characterized by transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The performances of catalysts for methanol electrooxidation were investigated by electrochemical methods. The results showed that Pd/CNTs -GNPs(1/4) (the mass fraction of GNPs was 1/4) cata- lyst exhibited a large electrochemical surface area and high performances for methanol electrooxidation, and its peak current density of methanol oxidation was 1.97 times that of the Pd/CNTs catalyst. The high activity of the cata- lyst is attributed to the good dispersion of Pd nanoparticles on the one - dimensional/two - dimensional composite CNTs - GNPs support. The chronoamperometry test showed that Pd catalysts supported on the CNTs - GNPs hybrid support had stronger anti-poisoning abilities as compared to the Pd catalyst supported on a single carbon support.
CNTs-GNPs, hybrid support composed of carbon nanotubes (CNTs) and graphene nanoplates (GNPs) was prepared by a solid phase -liquid phase two-step mixing method. The Pd/CNTs -GNPs catalyst was prepared by depo- sition of Pd nanoparticles on composite carbon support by the ethylene glycol reduction method. The morphologies, compositions, and structures of catalysts were characterized by transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The performances of catalysts for methanol electrooxidation were investigated by electrochemical methods. The results showed that Pd/CNTs -GNPs(1/4) (the mass fraction of GNPs was 1/4) cata- lyst exhibited a large electrochemical surface area and high performances for methanol electrooxidation, and its peak current density of methanol oxidation was 1.97 times that of the Pd/CNTs catalyst. The high activity of the cata- lyst is attributed to the good dispersion of Pd nanoparticles on the one - dimensional/two - dimensional composite CNTs - GNPs support. The chronoamperometry test showed that Pd catalysts supported on the CNTs - GNPs hybrid support had stronger anti-poisoning abilities as compared to the Pd catalyst supported on a single carbon support.
2022, 38(11): 2173-2180
doi: 10.11862/CJIC.2022.209
Abstract:
Cd2SnO4 was prepared by hydrothermal-calcination method and a series of MoS2/Cd2SnO4 composite materials were prepared by ultrasonic mixing method. To analyze the structures and morphologies of the Cd2SnO4 and MoS2/Cd2SnO4 composite materials, X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy were used. The effect of the doped amount of MoS2 on the gas sensing properties of MoS2/Cd2SnO4 composite materials was investigated. The results showed that when the mass ratio of MoS2 to Cd2SnO4 was 2.5%, the response of the gas sensor of MoS2/Cd2SnO4 composite material to 100 μL·L-1 formaldehyde vapor at 170 ℃ was 40.0 and the detection limit reached 0.1 μL·L-1.
Cd2SnO4 was prepared by hydrothermal-calcination method and a series of MoS2/Cd2SnO4 composite materials were prepared by ultrasonic mixing method. To analyze the structures and morphologies of the Cd2SnO4 and MoS2/Cd2SnO4 composite materials, X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy were used. The effect of the doped amount of MoS2 on the gas sensing properties of MoS2/Cd2SnO4 composite materials was investigated. The results showed that when the mass ratio of MoS2 to Cd2SnO4 was 2.5%, the response of the gas sensor of MoS2/Cd2SnO4 composite material to 100 μL·L-1 formaldehyde vapor at 170 ℃ was 40.0 and the detection limit reached 0.1 μL·L-1.
2022, 38(11): 2181-2190
doi: 10.11862/CJIC.2022.234
Abstract:
Cu-modified nitrogen-doped carbon (Cu-N-C) and Fe/Cu-modified nitrogen-doped carbon with carbon nanotube (Fe/Cu-N-C/CNT) catalysts were prepared by in situ chemical synthesis combined with an ion exchange method. As counter electrode in dye-sensitized solar cells (DSSCs), the electrochemical properties and photovoltaic performance of these two catalysts in I3-/I- electrolyte were explored. The structure and morphology of as-prepared catalysts were characterized by X-ray diffraction (XRD), Raman spectra, X-ray photoelectron spectra (XPS), and field emission scanning electron microscope (FESEM). The results showed that the graphitization degree of Fe/Cu-N-C/CNT was higher than that of Cu-N-C, which is more favorable for charge transfer during I3- reduction process. The photovoltaic tests results showed that the DSSCs based on Fe/Cu-N-C/CNT CE achieved a power conversion efficiency (PCE) of 7.55%, higher than Cu-N-C (6.99%) and Pt (6.76%) under the same conditions. 50 cycles continuous cyclic voltammetry scanning showed that Fe/Cu-N-C/CNT had better electrochemical stability than Cu-N-C. This robust behavior can be mainly attributed to the synergistic effect between the bimetallic active sites (Fe/Cu) and the nitrogen-doped carbon network with CNTs, which results in a pronounced decrease in the charge-transfer resistance and superior device stability.
Cu-modified nitrogen-doped carbon (Cu-N-C) and Fe/Cu-modified nitrogen-doped carbon with carbon nanotube (Fe/Cu-N-C/CNT) catalysts were prepared by in situ chemical synthesis combined with an ion exchange method. As counter electrode in dye-sensitized solar cells (DSSCs), the electrochemical properties and photovoltaic performance of these two catalysts in I3-/I- electrolyte were explored. The structure and morphology of as-prepared catalysts were characterized by X-ray diffraction (XRD), Raman spectra, X-ray photoelectron spectra (XPS), and field emission scanning electron microscope (FESEM). The results showed that the graphitization degree of Fe/Cu-N-C/CNT was higher than that of Cu-N-C, which is more favorable for charge transfer during I3- reduction process. The photovoltaic tests results showed that the DSSCs based on Fe/Cu-N-C/CNT CE achieved a power conversion efficiency (PCE) of 7.55%, higher than Cu-N-C (6.99%) and Pt (6.76%) under the same conditions. 50 cycles continuous cyclic voltammetry scanning showed that Fe/Cu-N-C/CNT had better electrochemical stability than Cu-N-C. This robust behavior can be mainly attributed to the synergistic effect between the bimetallic active sites (Fe/Cu) and the nitrogen-doped carbon network with CNTs, which results in a pronounced decrease in the charge-transfer resistance and superior device stability.
2022, 38(11): 2191-2201
doi: 10.11862/CJIC.2022.221
Abstract:
Three methods (urea hydrothermal-calcination, chemical bath deposition-calcination, and oxalate pyrolysis) were used to prepare Co3O4 powder materials with different morphologies, which were named Co3O4-A, Co3O4-B, and Co3O4-C, respectively. All of them were taken as catalysts to activate peroxymonosulfate (PMS) for the degradation of methylene blue (MB). It is found that these Co3O4 materials were quite different in their catalytic performance. Under the assistance of Co3O4-A, Co3O4-B, and Co3O4-C, the PMS decomposition reaction rate constants were measured as 0.047 1, 0.217 4, and 0.003 7 min-1, while the degradation ratios of MB were 91.25% (reaction time: 50 min), 100.00% (reaction time: 25 min), and 31.55% (reaction time: 50 min), respectively. That is, Co3O4-B had the best catalytic performance. To make clear the difference in the catalytic ability of Co3O4, a series of characterizations were carried out. It is discovered that these Co3O4 materials are different in many ways such as crystallinity, microstructure, specific surface area, surface oxygen vacancy concentration, and surface hydroxyl density. And it is confirmed that the primary factor influencing the catalytic performance of Co3O4 is the surface hydroxyl density. In addition, the optimized parameters for MB degradation in the Co3O4-B/PMS reaction system were determined as follows: reaction temperature 25 ℃, catalyst dosage 0.02 g·L-1, and PMS dosage 0.6 mmol·L-1, where the MB degradation ratio was as high as 98.33%. Moreover, the reactive oxygen species ·SO4-, ·OH, ·O2- and 1O2 were all detected in the Co3O4-B/PMS system according to the quenching experiments and electron paramagnetic resonance tests, and sulfate radicals were identified as the primary reactive oxygen species.
Three methods (urea hydrothermal-calcination, chemical bath deposition-calcination, and oxalate pyrolysis) were used to prepare Co3O4 powder materials with different morphologies, which were named Co3O4-A, Co3O4-B, and Co3O4-C, respectively. All of them were taken as catalysts to activate peroxymonosulfate (PMS) for the degradation of methylene blue (MB). It is found that these Co3O4 materials were quite different in their catalytic performance. Under the assistance of Co3O4-A, Co3O4-B, and Co3O4-C, the PMS decomposition reaction rate constants were measured as 0.047 1, 0.217 4, and 0.003 7 min-1, while the degradation ratios of MB were 91.25% (reaction time: 50 min), 100.00% (reaction time: 25 min), and 31.55% (reaction time: 50 min), respectively. That is, Co3O4-B had the best catalytic performance. To make clear the difference in the catalytic ability of Co3O4, a series of characterizations were carried out. It is discovered that these Co3O4 materials are different in many ways such as crystallinity, microstructure, specific surface area, surface oxygen vacancy concentration, and surface hydroxyl density. And it is confirmed that the primary factor influencing the catalytic performance of Co3O4 is the surface hydroxyl density. In addition, the optimized parameters for MB degradation in the Co3O4-B/PMS reaction system were determined as follows: reaction temperature 25 ℃, catalyst dosage 0.02 g·L-1, and PMS dosage 0.6 mmol·L-1, where the MB degradation ratio was as high as 98.33%. Moreover, the reactive oxygen species ·SO4-, ·OH, ·O2- and 1O2 were all detected in the Co3O4-B/PMS system according to the quenching experiments and electron paramagnetic resonance tests, and sulfate radicals were identified as the primary reactive oxygen species.
2022, 38(11): 2202-2212
doi: 10.11862/CJIC.2022.219
Abstract:
TiB2 support was prepared by molten salt method and Co/TiB2 magnetic recyclable nano-catalyst was prepared by simple precipitation-deposition method, which was used for catalytic hydrogen evolution in ammonia borane (NH3BH3) solution at room temperature and synergistic degradation of p-nitrophenol (4-NP) and azo dye such as acid orange 7 (AO7), acid red 1 (AR1), methyl orange (MO), without light, heat, other external energy, and additives. The catalyst was characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, X-ray photoelectron spectroscopy, vibrating sample magnetometer, and other characterization methods. The results showed that Co nanoparticles were uniformly distributed on the surface of TiB2 support, and the grain size was about 40 nm, which was coated by TiB2 support with a typical strong metal-support interaction. Co/TiB2 exhibited excellent catalytic activity for hydrogen evolution from NH3BH3 solution at room temperature, with a rate of hydrogen evolution at 565.8 molH2·molcat-1·h-1. In the cascade reaction of degrading organic pollutants, 4-NP amination was catalyzed by Co/TiB2 with nearly 100% conversion within 7 min, and the reaction rate constant was up to 0.72 min-1. The reaction rate constant of degrading AO7 was the highest among the three azo dyes (0.34 min-1). A large number of hydrogen radicals (·H) was detected in the catalytic system of Co/TiB2/NH3BH3 by EPR-DMPO (EPR=electron paramagnetic resonance, DMPO=5, 5-dimethyl-1-pyrroline N-oxide) free radical capture experiment. Due to the strong reducibility of ·H radical, the catalytic system of Co/TiB2/NH3BH3 can aminate 4-NP into p-aminophenol (4-AP) and reduce the azo chromogen group (—N=N—) in azo dye molecules. At the end of the reaction, the catalyst could be recycled by introducing an external magnetic field to avoid secondary pollution to the water body.
TiB2 support was prepared by molten salt method and Co/TiB2 magnetic recyclable nano-catalyst was prepared by simple precipitation-deposition method, which was used for catalytic hydrogen evolution in ammonia borane (NH3BH3) solution at room temperature and synergistic degradation of p-nitrophenol (4-NP) and azo dye such as acid orange 7 (AO7), acid red 1 (AR1), methyl orange (MO), without light, heat, other external energy, and additives. The catalyst was characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, X-ray photoelectron spectroscopy, vibrating sample magnetometer, and other characterization methods. The results showed that Co nanoparticles were uniformly distributed on the surface of TiB2 support, and the grain size was about 40 nm, which was coated by TiB2 support with a typical strong metal-support interaction. Co/TiB2 exhibited excellent catalytic activity for hydrogen evolution from NH3BH3 solution at room temperature, with a rate of hydrogen evolution at 565.8 molH2·molcat-1·h-1. In the cascade reaction of degrading organic pollutants, 4-NP amination was catalyzed by Co/TiB2 with nearly 100% conversion within 7 min, and the reaction rate constant was up to 0.72 min-1. The reaction rate constant of degrading AO7 was the highest among the three azo dyes (0.34 min-1). A large number of hydrogen radicals (·H) was detected in the catalytic system of Co/TiB2/NH3BH3 by EPR-DMPO (EPR=electron paramagnetic resonance, DMPO=5, 5-dimethyl-1-pyrroline N-oxide) free radical capture experiment. Due to the strong reducibility of ·H radical, the catalytic system of Co/TiB2/NH3BH3 can aminate 4-NP into p-aminophenol (4-AP) and reduce the azo chromogen group (—N=N—) in azo dye molecules. At the end of the reaction, the catalyst could be recycled by introducing an external magnetic field to avoid secondary pollution to the water body.
2022, 38(11): 2213-2221
doi: 10.11862/CJIC.2022.225
Abstract:
Three metal-organic frameworks (MOFs) materials, CAU-10-X (X=H, NO 2, CH3), with different substituents (—X) were synthesized and the adsorption and capture properties of N2O from N2O/N2 mixtures were studied. Considering the experimental results of single-component adsorption isotherm, adsorption heat, and IAST (ideal adsorbed solution theory) selectivity, we found that the adsorption capacity of CAU-10-NO2 was significantly higher than that of the parent CAU-10-H in the low-pressure region, and it could effectively capture N2O from the N2O/N2 mixture, while CAU-10-CH3 showed the opposite effect. The penetration simulation of N2O/N2 mixture further proved that CAU-10-NO2 had a good ability to capture trace N2O, and the cycle experiment showed that CAU-10-NO2 had good stability.
Three metal-organic frameworks (MOFs) materials, CAU-10-X (X=H, NO 2, CH3), with different substituents (—X) were synthesized and the adsorption and capture properties of N2O from N2O/N2 mixtures were studied. Considering the experimental results of single-component adsorption isotherm, adsorption heat, and IAST (ideal adsorbed solution theory) selectivity, we found that the adsorption capacity of CAU-10-NO2 was significantly higher than that of the parent CAU-10-H in the low-pressure region, and it could effectively capture N2O from the N2O/N2 mixture, while CAU-10-CH3 showed the opposite effect. The penetration simulation of N2O/N2 mixture further proved that CAU-10-NO2 had a good ability to capture trace N2O, and the cycle experiment showed that CAU-10-NO2 had good stability.
2022, 38(11): 2222-2230
doi: 10.11862/CJIC.2022.228
Abstract:
The Z-scheme heterojunction photocatalyst Au/CoWO4/CNs (Au/CoNs-x, x=5, 10, 20, 50) was obtained by introducing Au into g-C3 N4 nanosheets (CNs) and CoWO4 composites via impregnation-calcination method. The introduction of Au could be a charge transport channel to accelerate the transfer of photogenerated electrons from CoWO 4 to CNs. Compared with CoWO 4/CNs, Au/CoNs-10 exhibited excellent photocatalytic activity for the degradation of methylene blue and tetracycline hydrochloride, and their apparent rate constants were improved from 0.289 and 0.360 h-1 to 0.499 and 0.637 h-1, respectively. Optical and electrical tests and free radical trapping experiments indicate that the significantly improved photocatalytic performance of Au/CoNs-10 is mainly due to the construction of Z-scheme heterojunction, which reduces the recombination rate of photogenerated electrons and holes, promotes high oxidation activity and accelerates the formation of hydroxyl radicals (·OH) and superoxide radicals (·O2-) with high oxidation ability.
The Z-scheme heterojunction photocatalyst Au/CoWO4/CNs (Au/CoNs-x, x=5, 10, 20, 50) was obtained by introducing Au into g-C3 N4 nanosheets (CNs) and CoWO4 composites via impregnation-calcination method. The introduction of Au could be a charge transport channel to accelerate the transfer of photogenerated electrons from CoWO 4 to CNs. Compared with CoWO 4/CNs, Au/CoNs-10 exhibited excellent photocatalytic activity for the degradation of methylene blue and tetracycline hydrochloride, and their apparent rate constants were improved from 0.289 and 0.360 h-1 to 0.499 and 0.637 h-1, respectively. Optical and electrical tests and free radical trapping experiments indicate that the significantly improved photocatalytic performance of Au/CoNs-10 is mainly due to the construction of Z-scheme heterojunction, which reduces the recombination rate of photogenerated electrons and holes, promotes high oxidation activity and accelerates the formation of hydroxyl radicals (·OH) and superoxide radicals (·O2-) with high oxidation ability.
2022, 38(11): 2231-2237
doi: 10.11862/CJIC.2022.233
Abstract:
X⁃ray powder diffraction (XRD), X⁃ray fluorescence spectroscopy (XRF), and scanning electron microscope⁃energy dispersive X⁃ray spectroscopy (SEM⁃EDS) have been used to analyze the inorganic pigments chemical composition of the two Tang Dynasty painted pottery figurines unearthed from the Tang Dynasty tomb M16 in Xicao, Xi'an. The results showed that the painted pottery figurines contain various inorganic pigments, which show that the component of red pigments was Pb3O4; the white pigments were PbCO3 and CaCO3; the pink pigments were made up of red Pb3O4 and white PbCO3; the cyan pigment was a mixture of verdigris Cu2(OH)2CO3 and bluestone Cu3(OH)2 (CO3)2.
X⁃ray powder diffraction (XRD), X⁃ray fluorescence spectroscopy (XRF), and scanning electron microscope⁃energy dispersive X⁃ray spectroscopy (SEM⁃EDS) have been used to analyze the inorganic pigments chemical composition of the two Tang Dynasty painted pottery figurines unearthed from the Tang Dynasty tomb M16 in Xicao, Xi'an. The results showed that the painted pottery figurines contain various inorganic pigments, which show that the component of red pigments was Pb3O4; the white pigments were PbCO3 and CaCO3; the pink pigments were made up of red Pb3O4 and white PbCO3; the cyan pigment was a mixture of verdigris Cu2(OH)2CO3 and bluestone Cu3(OH)2 (CO3)2.
