Mesoporous silica materials have attracted much attention because of their large surface area, uniform pore-size distribution, large pore size, and wide potential applications in the fields of separation, adsorption, and catalysis. The progress in the removal of volatile organic compounds (VOCs, mainly containing hydrocarbons, methanol, formaldehyde, acetone, benzene, toluene, naphthalene, and ethyl acetate) by mesoporous silica materials and supported catalysts in recent years is reviewed. The effect of the structure of mesoporous silica materials on the adsorption of VOCs is discussed. We also discuss the catalytic performance and reaction mechanism for catalytic VOC oxidation over supported catalysts. The recent developments in catalytic combustion of toluene are examined in detail. We found that the surface environment, pore structure, and morphology of mesoporous silica materials are the main factors influencing adsorption of VOC molecules. The application of noble metal catalyst focuses on improving poison resistance and reducing cost. The research on non-noble metal catalysts focuses on developing supported mixed-metal oxide catalysts with high activity. Future developments of mesoporous silica materials and supported catalysts are highlighted. The design of the catalyst can be carried out from two aspects: the silica support and the mesoporous channel. This review will be helpful in choosing an appropriate catalyst for the removal of VOCs with high activity and stability.

The experimental infrared (IR), nuclear magnetic resonance (NMR), and ultraviolet (UV) spectra, and density functional theory (DFT) calculations of the novel compound N,N'-di[3-hydroxy-4-(2-benzothiazole) phenyl]urea (4-DHBTU) are presented. Compared with the UV spectra of the 2-(4-amino-2-hydroxyphenyl) benzothiazole (4-AHBT) monomer, the experimental spectra of 4-DHBTU, a dimer of 4-AHBT, show dualwavelength absorption with significantly enhanced absorption intensity and an obvious red shift of the maximum absorption peak. Analysis of the experimental spectra and the DFT calculations shows that the structures of cis-C₁₁ and trans-C₁₁ are the two most stable conformers, and that the main reason for the different UV spectral properties of the dimer and monomer is the coexistence of cis-C₁₁, trans-C₁₁, cis-C₂₂, and trans-C₂₂ in the 4-DHBTU sample. In addition, the DFT calculations indicate that a hydrogen-bonding interaction between 4-DHBTU and the dimethyl sulfoxide (DMSO) solvent leads to a large 1H NMR chemical shift for atoms 15H and 16H in 4-DHBTU.

The dynamics of the first excited singlet electronic state (S₁) of o-dichlorobenzene was investigated in real time by the femtosecond pump-probe method combined with time-of-flight mass spectroscopy and the photoelectron velocity mapping technique. The lifetime of the S₁ vibrational ground state was determined experimentally to be (651 ± 10) ps, corresponding to the intersystem crossing process from the S₁ state to the triplet state. Two decay channels were found in the S₁ vibrationally excited mode 9a₂18a₂. The fast process (lifetime constant (458 ± 12) fs) is because of the internal conversion from the S₁ vibrationally excited mode to the highly vibrationally excited ground state (S₀). The slow process (lifetime constant (90 ± 10) ps) is attributed to the intersystem crossing process from the S₁ state to the triplet state (T₁). Photoelectrons with long lifetime characteristics in the spectrum might be connected with the intersystem crossing process. Enhanced spinorbital coupling in the S₁ highly vibrationally excited state accelerates the intersystem crossing process.

The ultrafast dynamics of benzene on the S₂ state have been investigated by femtosecond time-resolved mass spectroscopy coupled with photoelectron imaging. The benzene molecule was excited to the S₂ state by two 400 nm photons, and subsequently probed by one 267 nm photon. The timedependent ion yield of the parent ion consists of two components with different lifetimes. The first component at (90 ± 1) fs is because of internal conversion from the S₂ state to the S₁/S₀ state. The second one, i.e., (5.0 ± 0.2) ps, is due to decay of the S₁ state. The observed lifetime of the second component is shorter than previous results, indicating the existence of an additional decay process. With photoelectron spectra extracted from the time-resolved photoelectron imaging, this newly found deactivated process is assigned to intersystem crossing from the vibrational excited S₁ state to the hot triplet state T₃.

We present a comprehensive investigation of the phosphorescence spectrum of Ir(ppy)₃ (ppy = 2-phenylpyridine), which is greatly influenced by vibration of the complex. General formalism of the emission spectrum is derived using a thermal vibration correlation function formalism for the transition between two adiabatic electronic states in polyatomic molecules. Displacements and Duschinsky rotation of potential energy surfaces are included within the framework of a multidimensional harmonic oscillator model. This formalism gives a reliable description of the emission spectrum of Ir(ppy)₃. The calculated results indicated that the 0→1 transition between the T₁ state and the S₀ state makes a large contribution to the emission spectrum, especially the vibrational modes below 1600 cm^-1. The breathing vibration of the ligands and the CC and CN stretching vibrations of benzene and pyridine rings are the main reasons for the appearance of the shoulder peak in the spectrum. The Boltzmann distribution makes the intensities of both the main and the shoulder peaks decrease, and the peaks are close together. When coupled with first-principles density functional theory (DFT) calculations, the present approach appears to be an effective tool to obtain a quantitative description and detailed understanding of the spectra and photophysical processes of polyatomic molecules.

The effect of strain on the band structure of the ZnO monolayer has been investigated by firstprinciples calculations based on density functional theory. The results reveal that the band structure of the ZnO monolayer presents different dependences on three types of strain. The band gap linearly and steeply varies under uniaxial zigzag compressive strain and armchair tensile strain, while it shows nonlinear dependence on the other types of strain. Therefore, uniaxial zigzag compressive strain and armchair tensile strain should be the most effective to tune the band gap. This work has significant implications for application of strain to tune the optical and catalytic properties of ZnO nanofilms.

Density functional theory at the BP86 level and natural bond orbital theory were used to investigate the influence of bridging ligands on the Ni―Ni interactions and magnetic coupling properties of metal string complexes [Ni₃(L)₄(NCS)₂] (L = 1: dpa^- (dipyridylamine), 2: mpta^- (4-methylpyridyl-thiazolylamine), 3: mdpa^- (4-methyl-dipyridylamine), 4: mppa-(4-methylpyridyl-3H-pyrrolylamine)) with potential applications in molecular wires. The following conclusions can be drawn. (1) The ground states of the complexes are antiferromagnetic (AF) singlet states, which correspond to the quintet state (HS). The energy and structure of HS is similar to AF. There are three-center-four-electron σ bonds (σ₂σ_nb¹σ^*1) along the Ni₃⁶⁺ chains. (2) The Ni―Ni and Ni―N distances are unaffected by methyl substituents on the pyridine ring of dpa^- ligands. However, substitution of the 3H-pyrrole ring or thiazole ring by the pyridine ring in mdpa^- lengthens the N1―N2 and Ni―Ni distances but shortens the Ni2―N2 distance. These effects of the thiazole ring are weaker than those of the 3H-pyrrole ring. Therefore, the strength of the Ni―Ni interaction is 1 ≈ 3 > 2 > 4. (3) The predicted J_ab values of 3 and 4 are -103 and -88 cm^-1, respectively. The AF magnetic coupling effects of the complexes increase with increasing Ni―Ni interaction strength: the stronger the Ni―Ni interaction, the greater the direct magnetic coupling in the σ orbitals along the Ni₃⁶⁺ chains. In addition, the stronger the Ni2―N2 interaction, the larger the indirect magnetic coupling involving the bridging ligand. The direct magnetic coupling is stronger than the indirect magnetic coupling.

Different types of 1-ethyl-3-methylimidazolium (EMIM) ionic liquid compounds, including halides, tetrafluoroborate, tribromide, diiodobromate, chloroaluminate, and bromine aluminate, have been investigated using quantum chemical calculations. First, geometry optimizations of the ion systems, including {[EMIM]X_n}^(n-1)- (X = Cl, Br, I, BF₄, AlCl₄, AlBr₄, Br₃, IBrI, FHF; n = 2, 3) and {[EMIM]₂X_n'}^(n'-2)- (n' = 3, 4, 5), were performed using the density functional theory (DFT) B3LYP method together with the 6-311++G(d,p) (6-311G(d,p) for I) basis set. The vibrational spectra were also calculated for the EMIM halides and tetrafluoroborate. The obtained structures and vibrational spectra were consistent with experimental results. In addition, a linear correlation between melting point and interaction energy was obtained for the {[EMIM]₂X_n'}^(n'-2)- models of the compounds studied.

Density functional theory (DFT) calculations of the reaction mechanisms and potential energy surfaces for the addition reactions of CH₃OH to several germasilenes were performed at the B3LYP/6-311++G(d,p) level. The effect of the polarity of the Si=Ge double bond in germasilenes on the regioselectivity of the addition reactions was also investigated. The results indicate that germasilenes can react with a monomer or dimer of CH₃OH. All reactions start with formation of nucleophilic or electrophilic complexes. The dimer of CH₃OH adds to H₂Si=GeH₂ kinetically more easily than the monomer. However, the situation is generally the opposite for substituted germasilenes. There is a kinetic disadvantage of substituting phenyl (Ph) or SiMe₃ groups for H atoms in H₂Si=GeH₂ in the addition reactions, and the effect of the SiMe₃ group is more remarkable than that of the Ph substituent. Both the polarity of the Si=Ge double bond and the strength of the Si-O (Ge-H) and Ge-O (Si-H) bonds affect the regioselectivity of the addition reactions.

Cyclic voltammetry and chronoamperometry have been used to investigate the mechanism of ld electrodeposition on the n-Si(111) electrode surface from a citrate bath, which had successfully applied to directly electroplate a dense ld film on the silicon surface. The results show that Au electrodeposition on the n-type silicon surface is an irreversible process, and the nucleation overpotential reaches 250 mV. According to Cottrell equation, the diffusion coefficient (D) is calculated to be (1.81 ± 0.14) × 10^-4 cm₂·s^-1. The Scharifker-Hills (SH) model was used to analyze the experimental data. Agreement between the fitting curves and the theoretical curves confirms that the nucleation process of Au electrodeposition on the n-type silicon surface follows the progressive nucleation mechanism with three-dimensional growth under diffusion control. To further confirm the progressive nucleation mechanism, scanning electron microscopy (SEM) was used to observe the nucleation and growth of Au deposits at the initial stage of electrodeposition. The SEM results show that the morphology and density of the Au deposits are affected by the electrochemical deposition potential and time.

A nanocomposite composed of N-doped mesoporous carbon material (NDMPC) and carboxymethylated chitosan (CMCH) was fabricated by mechanical co-mixing and used as an enzyme matrix. A novel glucose/O₂ enzymatic biofuel cell was fabricated with a Nafion ion-exchange membrane consisting of a laccase (Lac)-entrapped biocathode and glucose oxidase-incorporated bioanode. Enzyme electrodes were prepared by the dripping coat and air-dried method. The performance of the laccase-based electrode as a biocathode in a fuel cell and an oxygen electro-chemical sensor was characterized by cyclic voltammetry in combination with the rotating disk electrode technique, linear scanning voltammetry (LSV), and chronoamperometry. UV-Vis spectrometry and graphite furnace atomic absorption spectroscopy were used to investigate the configuration of enzyme molecules on the surface of electrode and to evaluate the enzyme loading of the matrix on the electrode interface. The results from the experiments showed that the laccasebased cathode displayed direct electron transfer between the active centre in laccase (T₁) and the conductive matrix without any external electron mediators (apparent electron transfer rate 0.013 s^-1). A minor overpotential for oxygen reduction (150 mV) was also observed. Through further comparison of the intra-molecule electron relay rate (1000 s^-1), substrate turnover frequency (0.023 s^-1), and previous enzyme-conductive matrix electron transfer rate, quantitative analysis showed that the latter was the rate-determining step in the whole catalytic cycle of the oxygen reduction reaction. This laccase-based electrode as an oxygen electrochemical sensor for detecting oxygen showed a low detection limit (0.04 μmol·dm^-3), high sensitivity (12.1 μA·μmol^-1·dm³), and affinity for oxygen (K_M = 8.2 μmol·dm^-3). This laccase-based cathode also had advantages such as excellent reproducibility, long-term usability, thermal stability, and pH endurance. The results for the fabricated biofuel cell showed an open circuit voltage of 0.38 V and a maximal energy output density of 19.2 μW·cm^-2, maintaining greater than 60% of the initial value even after continuous work for 3 weeks under optimal conditions.

Multi-walled carbon nanotubes (MWCNTs) were modified with the long-chain polymer poly (diallyldimethylammonium chloride) (PDDA) and used as support for Pt nanoparticles (NPs). Pt/PDDA/ MWCNTs electrocatalysts were prepared by electrostatic adsorption of Pt NPs on the PDDA/MWCNTs support. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) characterization revealed that the Pt NPs were well dispersed on the PDDA/MWCNTs support, with an average diameter of ~3.6 nm. Thermo gravimetric analysis showed that the loading of Pt was 36%(w). Rotating disk electrode (RDE) measurements showed that the Pt/PDDA/MWCNTs catalyst had excellent electrocatalytic activity for oxygen reduction in alkaline medium. Compared with commercial Pt/C (40%(w)), the Pt/PDDA/MWCNTs catalyst exhibited a positive shift of 30 mV for the oxygen reduction onset and half-wave potential. Kinetics study further confirmed the significantly enhanced oxygen reduction activity of the Pt/PDDA/MWCNTs catalyst in the alkaline medium.

In this paper, an orientational anchoring transition of the thermotropic nematic liquid crystal (LC) (4-cyano-4'-pentylbiphenyl (5CB)) driven by hydrogen-bond (HB) interaction at the LC-aqueous interface is presented. After a 5CB film is introduced onto an aqueous solution of phenols such as nitrophenol, the alignment of 5CB changes from planar to homeotropic, which is attributed to HB interaction between 5CB and phenols at the LC-aqueous interface. On the other hand, the interaction of pnitrophenol or m-nitrophenol with bovine serum albumin (BSA) is imaged by the LC sensor. Overall, the results provide new insight into interfacial phenomena occurring at the LC-aqueous interface, and hold the potential for biological and chemical sensing techniques based on HB interaction.

Microwave hydrogen plasma was used to introduce hydrogen termination on the diamond surface. Optical emission spectroscopy (OES) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) were used to characterize the active radicals in the plasma and the concentration of H-termination on the diamond surface, respectively. Thermal hydrogenation treatment carried out by hot filament heat in a hydrogen atmosphere was also proposed for incorporation of H-termination on the diamond surface. The results showed that the CH radical content in the microwave plasma and the H-termination concentration on the diamond surface after microwave plasma treatment were both facilitated by increasing the substrate temperature, plasma density, and input power. Interestingly, thermal hydrogenation treatment can produce Htermination on the diamond surface compared with to a similar extent to microwave plasma treatment. These observations show that the crucial factor for forming the H-terminated diamond surface is the surface chemical reaction controlled by temperature, rather than the plasma etching effect. When the temperature is above 500 ℃, C=O bonds on the O-terminated diamond surface decompose to CO and leave dangling bonds, which then connect with atomic or molecular hydrogen.

Perfluorosulfonic acid functionalized carbon-based solid acid catalysts were prepared by liquid deposition of perfluorosulfonic acid-polytetrafluoroethylene (PTFE) copolymer using carbon nanotubes, mesoporous carbon molecular sieves, and nitrogen-doped mesoporous carbon as precursors. The obtained catalysts were characterized by N₂ adsorption, thermogravimetric analysis (TG), transmission electron microscope (TEM), Fourier transform Infrared (FTIR) spectrometer, and potentiometric titration. Their catalytic behavior in the Friedel-Crafts (F-C) alkylation of anisole was also investigated. It was found that the surface area of the precursor and its interaction with perfluorosulfonic acid play important roles in the preparation of highly active catalysts. The highest activity as well as the best stability was observed over perfluorosulfonic acid functionalized nitrogen-doped mesoporous carbon.

Supports have a significant effect on the dispersion and stability of Au nanoparticles because of the support-metal interaction. In the present work, TiO_x/SiO₂ composite supports were prepared by the surface sol-gel (SSG) method to enhance the binding strength between the metal and the support. The samples were characterized by low-energy ion scattering (LEIS) spectroscopy, X-ray photoelectron spectroscopy (XPS), Xray diffraction (XRD), transmission electron microscopy (TEM), and N₂ physisorption (BET). The results showed that the TiO_x species in TiO_x/SiO₂ were highly dispersed on SiO2 with the formation of Ti―O―Si linkages. The catalytic activity and stability for CO oxidation on Au/TiO_x/SiO₂ were significantly enhanced, because of the better dispersion of Au nanoparticles compared with Au/TiO₂.

A series of non-platinic lean NO_x trap (LNT) CuO-K₂CO₃/TiO₂ catalysts with different Cu loadings were prepared by sequential impregnation, and they showed relatively od performance for lean NO_x storage and reduction. The catalyst containing 8% (w) CuO showed not only the largest NO_x storage capacity of 1.559 mmol·g^-1 under lean conditions, but also the highest NO_x reduction percentage of 99% in cyclic lean/rich atmospheres. Additionally, zero selectivity of NO_x to N₂O was achieved over this catalyst during NO_x reduction. Multiple techniques, including X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), temperature-programmed desorption of CO₂ (CO₂-TPD), extended X-ray absorption fine structure (EXAFS), temperature-programmed reduction of H₂ (H₂-TPR), and in-situ diffuse reflectance Fourier-transform infrared spectroscopy (DRIFTS), were used for catalyst characterization. The results indicate that highly dispersed CuO is the main active phase for oxidation of NO to NO₂ and reduction of NO_x to N₂. The strong interaction between K₂CO₃ and CuO was clearly revealed, which favors NO_x adsorption and storage. The appearance of negative bands at around 1436 and 1563 cm^-1, corresponding to CO₂ asymmetric stretching in bicarbonates and -C=O stretching in bidentate carbonates, showed the involvement of carbonates in NO_x storage. After using the catalysts for 15 cycles of NO_x storage and reduction in alternative lean/rich atmospheres, the CuO species in the catalysts showed little change, indicating high catalytic stability. Based on the results of in-situ DRIFTS and the other characterizations, a model describing the NO_x storage processes and the distribution of CuO and K₂CO₃ species is proposed.

The catalytic activity, hydrothermal aging resistance, and sulfur tolerance of a Pd-Pt-based methane oxidation catalyst were evaluated in a fixed fluidized bed reactor containing simulated lean-burn natural gas vehicle exhaust gases. Zirconium-doped Pd-Pt/Al₂O₃ (Pd-Pt/Zr_xAl_(1-x)O_(3+x)/2) was found to significantly improve the catalytic activity, hydrothermal aging resistance, and sulfur tolerance. Zr-modified alumina supports were prepared by co-precipitation with molar ratios of Zr to Al of 0 : 1, 0.25 : 0.75, 0.5 : 0.5, 0.75 : 0.25, and 1 : 0. The Pd-Pt bimetallic catalysts containing 1.5% (w, mass fraction) Pd and 0.3% (w) Pt supported on the above-modified composite supports were prepared by the co-impregnating method. The catalysts were characterized by N₂ adsorption/desorption, X-ray diffraction(XRD), H₂ temperatureprogrammed reduction (H₂-TPR), O₂ temperature-programmed desorption, and X-ray photoelectron spectroscopy (XPS). The results show that the crystallinity of the samples, dispersion of the active component, number of Pd²⁺ species, and electron density around Pd2+ species increase after addition of ZrO₂ to Al₂O₃ supports. Compared with the activity results of Pd-Pt/Al₂O₃ and Pd-Pt/ZrO₂ catalysts after different pretreatment conditions, the performance of the catalyst is greatly enhanced by adding ZrO₂ in the Al₂O₃ supports, and Pd-Pt/Zr_0.5Al_0.5O_1.75 shows the best catalytic activity, strongest hydrothermal aging resistance, and highest sulfur tolerance among the investigated catalysts.

From the viewpoint of practical application, enhancing the stability and lifetime of organic lightemitting diodes (OLED) is a al of research. A MgF₂ modified tris(8-hydroxyquinoline)-aluminum (Alq₃) hybrid superstructure was realized by collosol infiltration of a Mg(CF₃COO)_2-x(CH₃COO)_x precursor onto Alq₃. Alq₃ was well-dispersed in a large amount of Mg(CF₃COO)_2-x(CH₃COO)_x gel precursor solution, and after concentration a well-dispersed composite paste was produced. By heating the paste to 300 ℃, Alq₃ transformed to the superstructured ε-phase, and MgF₂ homogeneously incorporated because of od gel precursor infiltration and in situ deposition. The MgF₂-modified Alq₃ nanocomposite with superstructure has the same electroluminescence (EL) spectrum as Alq₃, with a dramatic improvement of the anti-aging performance of the OLED compared with Alq₃ because of the uniform assembly and well-defined structure. The effect of the amount of Mg(CH₃COO)₂ reactant on the OLED device anti-aging performance was investigated. The results showed that for the Alq₃-MgF₂ nanocomposite with 5% (molar fraction) of the Mg(CH₃COO)₂ reactant, the luminance remained at the initial state of 93.5% after aging for 72 h in air. However, the luminance of the Alq₃-based OLED almost disappeared after aging for 24 h under the same conditions. This work on inorganic material modified luminescent materials makes significant progress towards stable OLED.

Quenching of a fluorescent probe by amino acid residues can provide valuable information about the structural and conformational dynamics of a biopolymer. Herein, we systematically investigated the ultrafast fluorescence quenching dynamics of Eosin Y in the presence of N-acetyl-tyrosine (AcTyr) in H₂O and D₂O solutions using both femtosecond transient absorption and time-correlated single-photon counting experiments. We found that the quenching of the fluorescence of Eosin Y by AcTyr in aqueous solution is mainly because of the formation of a ground-state complex between Eosin Y and AcTyr. We also found that the lifetime of the ground-state complex formed between Eosin Y and AcTyr showed a clear kinetic isotope effect, indicating that the quenching of the fluorescence of Eosin Y by AcTyr in aqueous solution is via a proton-coupled electron transfer process.

Highly expressed in cancer 1 (HEC1) is a conserved mitotic regulator that is critical for spindle checkpoint control, kinetochore functionality, and cell survival. Overexpression of HEC1 has been detected in a variety of human cancers, and it is linked to poor prognosis of primary breast cancers. Thus, it is important to screen novel inhibitors with high affinity for HEC1. Machine learning (ML) methods were exhibiting od pharmacodynamics, and toxicity. In this work, two ML methods, support vector machines (SVMs) and random forests (RFs), were used to develop a classification method for searching inhibitors and non-inhibitors of HEC1 from the chemical library of structural diversity by screening characteristics of molecular descriptors. Both ML methods achieved promising prediction accuracies, and the RF model showed better performance. We performed virtual screening of HEC1 inhibitors by the RF model from an in-house database to screen potential HEC1 inhibitors. Two novel potential candidates were found. In vitro experiments of the two compounds showed that both had a certain degree of antitumor activity for the MDA-MB-468 and MDA-MB-231 breast cancer cell lines. Our study shows that ML methods are promising to design and virtually screen inhibitors of HEC1.

F₁-ATPase makes extensive interactions with ATP through forming a network of interactions around ATP. These interactions create a steady environment for ATP synthesis/hydrolysis. Thus understanding these interactions between ATP and F₁-ATPase is essential for understanding ATP synthesis/hydrolysis mechanism. We performed all-atom molecular dynamics (MD) simulations to elucidate these interactions and attempted to identify key residues which play important roles in stabilizing and positioning ATP. By examining the non-bonded energies between ATP and residues of βTP subunit in F₁-ATPase, it is found that residues 158-164, R189, Y345 have significant interactions with ATP. The loop segment (residues 158-164) and R189 surround ATP by a half and they interact with β and γ phosphates through forming a network of hydrogen bonds to constraint the motion of ATP triphosphate. The interaction network seals off the conformation of the catalytic site, creating a steady environment for ATP synthesis/hydrolysis. Additionally, ATP base is positioned by the π-π stacking interaction from Y345. However, ATP base can slide and move paralleling to the aromatic group of Y345. It is deduced that this motion may facilitate ATP hydrolysis.

Polycrystalline samples of (Gd_1-xCe_x)₂Zr₂O_7+x (0 ≤ x ≤ 0.7) were synthesized by solid-state reaction using NaF as a flux at 1000 ℃ to simulate Pu-immobilization in the Gd₂Zr₂O₇ matrix. Phase transformation and variation of the thermal expansion coefficients (TECs) and thermal conductivities (TCs) of the samples with temperature and composition were investigated. Powder X-ray diffraction (XRD) patterns show that pure Gd₂Zr₂O₇ has a weakly ordered pyrochlore structure, whereas Ce-containing samples (i.e., the Pu-simulated solidified samples) exhibit a defect fluorite structure even if x is as low as 0.1. When x reaches 0.7, the XRD peaks of these samples widen. In the Ce 3d X-ray photoelectron spectrum (XPS) of (Gd_1-xCe_x)₂Zr₂O_7+x there are six peaks located at binding energies of 881.7, 888.1, 897.8, 900.4, 907.1, and 916.1 eV, which are almost the same as the peaks of CeO2. The Ce 3d XPS reveals that the Ce species in (Gd_1-xCe_x)₂Zr₂O_7+x are tetravalent. The TECs of (Gd_1-xCe_x)₂Zr₂O_7+x (0 ≤ x ≤ 0.7) generally increase with increasing temperature. At the same temperature, the TECs and TCs exhibit the same variation trend with the composition of the simulated solidified forms: they decrease from x = 0 to 0.1 and then linearly increase from x = 0.1 to 0.7.

Hierarchical nanostructured γ-Al₂O₃ hollow microspheres were synthesized from KAl(SO₄)₂ and urea precursors by the microwave-assisted hydrothermal (MAH) method at 180 ℃ for 20 min followed by calcination at 600 ℃ for 2 h. The as-prepared sample was used to remove the organic dye Con red (CR) from aqueous solution. The results showed that the obtained γ-Al₂O₃ hollow microspheres are about 0.8-1.0 μm in diameter with a shell thickness of approximately 200 nm. The γ-Al₂O₃ hollow microspheres have a high surface area of 243 m²·g^-1 and a hierarchical meso-macroporous structure, which is beneficial for mass transfer in liquid processes. Therefore, the prepared γ-Al₂O₃ hollow microspheres exhibit faster adsorption and enhanced adsorption performance for CR than particles prepared by the hydrothermal method and commercial γ-Al₂O₃. The adsorption kinetic data follow the pseudo-second-order equation and the equilibrium data fit well to the Langmuir model. The maximum adsorption capacity (q_max) of the obtained γ-Al₂O₃ hollow microspheres calculated by the Langmuir model is up to 515.4 mg·g^-1 at 25 ℃. The γ-Al₂O₃ hollow microspheres prepared by the microwave-assisted hydrotherm method show promise as an adsorbent for environmental applications due to their hierarchical porous structure, high surface area, large pore volume, and adsorption capacity.