A tubular electrolyte-supporting solid oxide fuel cell (SOFC) was fabricated by a slip casting technique. Yttrium stabilized zirconia (YSZ) was used as the electrolyte and silver was used as both of the anode and cathode materials. Activated carbon was directly used to fuel the cell without any gas feeding. The cell, with an effective area of 2.5 cm2, gave a maximum power of 16 mW at 800 ℃. The relationship of the open circuit voltage vs temperature was consistent with the theoretical expectation. Operating the cell continuously and stably for 37 h at a constant current of 30 mA resulted in more than 42% (w) of the carbon fuel consumed, demonstrating that the cell was self-sustainable. Compared with the SOFCs with graphite fuel, the operation stability has been improved significantly and this is attributed to the greater microporosity and larger surface area of the activated carbon. The performance degraded rapidly after 37 h. A decrease in the active surface area of the carbon fuel, arising from carbon sintering and a reduction in the amount of fuel during the operation was assumed to be the main reason for the degradation. An electrochemical impedance measurement revealed that polarization resistance dominated the total loss of the cell. By analyzing the mechanisms of the cell reaction, we recognized that the cycle of the two reactions, i.e., the electrochemical oxidation of CO on the anode/electrolyte interface and the Boudouard reaction on the surface of the carbon fuel, maintained the cell operation. We suggest that a significant improvement in cell performance can be expected by using catalysts that promote these two reactions.

Four novel Salen-type mono-and bi-nuclear complexes were synthesized by a metal template method, and were characterized by elemental analyses, hydrogen nuclear magnetic resonance (1H NMR), electrospray ionization mass spectroscopy (ESI-MS), Fourier transforminfrared (FT-IR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, and circular dichroism(CD)spectroscopy. The thermodynamic behavior of the Salen-type Ni (II) complexes were studied by UV-Vis and CD spectra. We found that the coordination numbers for imidazole (Im) and N-methylimidazole (N-MeIm)were 2, but for 2-Et-4-MeImand 2-MeImthey were 1. The association constants of the systems decrease according to the following order: KΘ(Im) >KΘ(N-MeIm) >KΘ(2-Et-4-MeIm) >KΘ(2-MeIm). The thermodynamic parameters △rHΘm and △rSΘm were also determined. Results showed that the axial coordination process was driven by enthalpy and entropy.

The precursor powder of Ce0.9Sm0.1O2-δ(SDC) containing 5.0×10-4 (w) SiO2 as an impurity (SDCSi) was prepared by the sol-gelmethod and 0-3.0%(molar fraction, x)M was added to the SDCSi powder. The characterizations focused on phase structure, sintering behavior, relative density, electrical conductivity of all the samples were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and AC impedance spectroscopy. We find that M can reduce the sintering temperature about 100-200 ℃ and increase the relative density of the ceramics. The grain boundary conduction increased markedly for the 1.0%(x) M -loaded SDCSi ceramics as M can mitigate the harmful effects of the SiO2 impurity. These investigations have indicated that M is shown to be an effective sintering aid and a new scavenger of the grain boundary synchronously.

Commercially available PtRu/C catalyst was doped with Eu by chemical reduction and sintering, resulting in PtRuEux/C catalysts with different Eu contents. The catalysts were characterized by transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Results showed that Eu doping did not change the average size of the PtRu/C catalysts (ca 3 nm), and their surfaces were modified by both Eu metal and oxide. Cyclic voltammetry and chronoamperometry demonstrated that the activity of the PtRuEux/C catalysts was higher than that of commercial PtRu/C for methanol electrooxidation. Among the PtRuEux/C catalysts, PtRuEu0.3/C exhibited the best performance. The electrocatalytic oxidation of methanol on the catalyst was further investigated by in situ Fourier transforminfrared (FTIR) spectroscopy at molecular level. Results indicated that the adsorbed species derived from the dissociative adsorption of methanol on the catalysts were linear-bonded CO (COL). Eu doping decreased the oxidation potential of COL and thus significantly enhanced the activity of the catalysts and their tolerance to CO.

Grown in situ carbon nanotube chemically modified electrode (GSCNT-CME) was prepared by the in situ growth of carbon nanotube (CNT) onto a pretreated graphite electrode (GE) via catalytic chemical vapor deposition. The pretreated GE was prepared by direct current electrochemical deposition using a nickel catalyst. The deposited nickel and the obtained GSCNT-CME were characterized by optical microscopy, scanning electron microscopy (SEM), and energy dispersive X-ray diffraction(EDX). The electrochemical performance of the obtained GSCNT-CMEs were characterized by cyclic voltammetry using a [Fe(CN)6]3-/[Fe(CN)6]4- solution. Results showed that there was a layer of nickel on the pretreated GE surface after direct current electrochemical deposition and CNT with uniform tube diameters were present on the surface of the GE. The prepared GSCNT-CME has od current response sensitivity and od accuracy. It may be applied in electrochemical testing field.

A highly active and well-dispersed nanoscale Ptshell-Nicore/XC-72 electrocatalyst was synthesized. The Ni-core was reduced by NaH2PO2, followed by an in situ galvanic replacement to yield a Ni-Pt core-shell like structure. Complete coverage of the Ni core by a Pt shell was confirmed by various techniques including transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-visible (UV-Vis) spectrophotometry, and cyclic voltammetry (CV). A probe reaction of hydrogen electrooxidation showed that the electrocatalytically active surface area of Ptshell-Nicore/XC-72 is 1.2 times as large as that of Pt/C (JM), even though its theoretical Pt loading is only 40% that of Pt/C (JM). This improvement in activity is attributed to the interaction between the Pt shell and the Ni core.

The synergetic adsorption, antifogging and corrosion inhibition properties of polyaspartate (PASP) and dodecane phenol polyoxyethylene ether (OP-10) on A3 steel were investigated in 6 mol·L-1 HCl by weight loss and electrochemical techniques. Results showed that the combined inhibitor strongly inhibited the corrosion of A3 carbon steel in HCl. The efficiencies of corrosion inhibition and antifogging using 20 g·L-1 PASP were 94% and 83% , respectively. The inhibition efficiency decreased as the system temperature increased. The adsorption behavior of the combined inhibitor on the surface of the steel followed the amended Langmuir adsorption isotherm equation. The adsorption resulted in an entropy decrease and was a spontaneous and exothermic process. The combined inhibitors were anodic inhibitors.

An ionic liquid gel polymer electrolyte (ILGPE) based on 1-ethyl-3-methyl-imidazoliumhexafluorophosphate (EMIPF6), poly(vinylidenefluoride-hexafluoropropylene) (P(VDF-HFP) and LiPF6 was prepared by a solution casting method. Its ion transport characteristics and compatibility with LiFePO4 were investigated by cyclic voltammetry (CV), chronoamperometry, galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS). The results show that the ionic conductivity and electrochemical window at room temperature are 1.650×10-3 S·cm-1 and 5.0 V, respectively. The lithiation/delithiation reversibility was improved because of the formation of a passivation layer on the surface of the electrode during the charge-discharge cycles.

The interfacial structure and capacitance of a Pt foil electrode were investigated by electrochemical impedance spectroscopy in various ionic liquids including BMIMPF6, BMIMBF4, BMIMClO4, BMIMTf2N, BMIMCl, BMIMBr, C3OHMIMBF4, C3OHMIMClO4 and BMMIMPF6 (BMIM: 1-butyl-3-methylimidazolium, C3OHMIM: 1-(3-hydroxypropyl)-3-methylimidazolium, BMMIM: 1-butyl-2-methyl-3-methylimidazolium, Tf2N: bis(trifluoromethylsulfonyl)amide). The results indicate that when the anion and cation of the ionic liquid are of comparable size and do not adsorb specifically on the electrode, the“capacitance-potential”curve near the potential of zero charge exhibits either one peak or two peaks. The potential of zero charge corresponds to either the peak potential or the valley potential on the capacitance-potential curve with one peak or two peaks, respectively. When the potential is positive or negative to the potential of zero charge, the structure of the“electrode/ionic liquid”interface could be explained by the compact layer theories. In the presence of specific ion adsorption, the capacitance peak disappears and while the electrode potential shifts against the potential of zero charge, the interfacial capacitance rapidly increases. The effects of small Li+ ions on the electrode/ionic liquid interfacial structure and capacitance were also studied. When LiTf2N was added to BMIMTf2N, the small Li + ion changed the ionic composition and hence the structure of the electrode/ionic liquid interface, and also decreased the interfacial capacitance. Based on these findings, the arrangement and conformation of the anions and cations of the ionic liquid at the electrode/ionic liquid interface are elaborated under different conditions with particular attention to the specific adsorption of both the cation and the anion.

As one-dimensional (1D) TiO2 nanostructures can benefit charge transport and improve the performance of dye-sensitized solar cells (DSCs), they have attracted much attention recently. However, studies on how 1D nanostructures affect the charge transport have rarely been reported. In this study, an electrochemical impedance spectroscopy (EIS) analysis was carried out to scrutinize the charge transport properties of a TiO2 particle-titania nanotube composite film. The composite TiO2 film was prepared by electrophoretic deposition using two kinds of nanoparticles with different sizes (25 and 100 nm) and titania nanotubes (TNTs) as the starting powder. The influence of the powder's composition on DSCs based on the composite film was investigated to yield an optimum composition. It was found that large particles (LPs) increase the charge diffusion and cell performance before the mass fraction of the large particles reaches 20%. Compared with films fully consisted of particles, TNTs prove to facilitate electron transport within the TiO2 film. The optimummass ratio of TNTs:LPs:PPs (25 nmparticles) is 20:16:64.

Four porous carbon samples C-600, C-700, C-800, and C-900 were prepared by the carbonization of chitosan at 600, 700, 800, and 900 ℃ under N2 and had specific surface areas of 278, 461, 515, and 625 m2·g-1, respectively, based on nitrogen adsorption/desorption measurements. Their electrochemical properties were investigated by cyclic voltammetry (CV) and charge-discharge under constant current. The CV curves of C-800 have a rectangular shape and symmetrical anode and cathode processes. The capacitance of C-600, C-700, C-800, and C-900 are 96, 120, 154, and 28 F·g-1 derived fromthe galvanostatic charge-discharge curves at a current density of 50 mA·g-1, respectively. The C-800 composite electrode is highly stable and retains its capacitance well as the capacitance decreased by less than 2% after 1000 cycles at a current density of 1 A·g-1. Furthermore, with an increase in the concentration of the electrolyte, the shape of the CV curves of the C-800 based electrode becomes more and more rectangular and the specific current also increases. The relationship between the pore structures of the four porous carbon samples and their properties is discussed based on the experimental results. We suggest that chitosan-based porous carbon has potential application as electrochemical capacitor electrode materials.

New kinds of onion-like hollowcarbon nanoparticles (OC) with amean diameter of 40 nmwere synthesized by the pyrolysis of carbon black at 1000 ℃ in a nitrogen atmosphere using ferric nitrate as the catalyst precursor. By impregnating with a SnCl2/ethanol solution and oxidation in air at 350 ℃, OC doped SnO2 nanoparticle composites were obtained. Then, by rinsing with hydrochloric acid to remove the coated SnO2 nanoparticles, OC-encapsulated SnO2 nanoparticle composites were prepared. The morphologies and structures of OC and the composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The content of SnO2 in the composite was measured by thermogravimetric analysis (TGA). The electrochemical properties of the composites as anode materials for lithium-ion batteries were evaluated by galvanostatical method and cyclic voltammetry (CV). We found that after acid treatment the sample possessed a reversible capacity of 446 mAh·g-1 after 50 cycles and excellent cycle stability. This indicates that OC is a suitable matrix to buffer against volume expansion and to prevent the agglomeration of SnO2 nanoparticles.

We synthesized a 4,4'-bipyridine polyoxomolybdate ((4,4'-bipyridine)Mo7O22·H2O) single crystal supramolecular compound by a hydrothermal method and characterized its composition, thermostability, structure, spectra and electron properties by elemental analysis, thermal gravimetric and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), single crystal X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), and electron spin resonance (ESR). Experimental results show that the molecular formula of the supramolecular compound is C10H12Mo7N2O23 and it does not decompose below 320 ℃ in air. It belongs to the monoclinic system(space group P2/n) with a=1.22561(19) nm, b=0.55222(9) nm, c=1.8385(3) nm, β=103.221(2)°, V=1.2113(3) nm3, Z=2 and Dc=3.289 g·cm-3. The final statistics based on F2 are F=0.982, R1=0.0228 and wR2=0.0557 for I >2σ(I). The single crystal supramolecular compound consists of protonated 4,4'-bipyridine cations and polyoxomolybdate [Mo7O22]2- anions as well as lattice water. They form a two dimensional (2D) network through hydrogen bonds, electrostatic attraction, and intermolecular forces. The samples show photochromism under UV irradiation and thermochromism under annealing conditions. XRD and FTIR verify that before and after the color changes, the crystal structure of the samples is almost unchanged except for distortion. ESR spectra indicate that a difference exists between the thermochromic and photochromic mechanisms. This supramolecular compound with thermochromic and photochromic behaviors can serve as a reference model for a chromic mechanism and may have potential application in fields such as sensors and photosensitive materials.

Anovelmethod for the determination of surfactant criticalmicelle concentration (cmc), based on the fiber refractive index sensor principle was studied. The cmc of a representative anionic surfactant sodium dodecyl sulfate (SDS) and the cmc of a cationic surfactant cetyltrimethylammonium bromide (CTAB) were found to be 8.05×10^-3 and 9.11×10^-4 mol·L^-1 respectively at 25 ℃ using this method, which are in od agreement with literature values. Further determinations of surfactant cmc under various conditions show that the influence of temperature and the inorganic salt NaCl on the accuracy of the method is slight. Therefore, the applicability of the method is proven. We also tested the repeatability and stability of this method. The relative standard deviation (RSD) for the measurement results was 0.17%, which is consistent with our expectation.

The dilational properties of the zwitterionic Gemini surfactant C8E4NC12, cationic Gemini surfactant C12NE3NC12, and anionic Gemini surfactant C8E4C8 with polyoxyethylene spacers at the air/water surface and decane/water interface were investigated by the Langmuir trough method. The influence of concentration on dilational properties was explored. Experimental results showed that C8E4NC12 had higher dilational elasticity and viscosity because of the Coulombic attraction between molecules. The interfacial dilational properties are similar to those of the surface for C8E4NC12. Although C8E4C8 and C12NE3NC12 have the same sign electric charge, the rigid benzene ring of C8E4C8 leads to a different orientation of the long hydrophobic chain on the surface. Therefore, they have different surface dilational properties. Oil molecules can change the interfacial molecular orientation of long-chain alkyl groups, which results in a lower interfacial dilational elasticity and viscosity than that of the surface. Possible schematic diagrams of adsorbed Gemini molecules with different charge at the air/water surface and decane/water interface are proposed. These were verified by the characteristic parameters of the relaxation processes.

Precursors of CeO2 were synthesized in a reverse microemulsion composed of cetyltrimethylammonium bromide (CTAB), 1-butanol, 1-octane, Ce(NO3)3 brine (ammonia). The optimum calcination temperature (550 ℃) was derived from thermogravimetry (TG) analysis and X-ray powder diffraction (XRD). The CeO2 nanoparticles were then prepared by calcining the precursors at 550 ℃. The structures, morphologies, size, and UV absorption properties of the CeO2 nanoparticles were characterized by XRD, transmission electron microscopy (TEM), and UV-Vis spectroscopy. Cubic crystalline CeO2 nanoparticles of 5 -18 nm in size and with od monodispersity were obtained using this method. The influences of the mass ratio of 1-octane to 1-butanol and the concentration of Ce(NO3)3 on the size of the CeO2 nanoparticles were studied. Results showed that CeO2 nanoparticle size was dependent on the mass ratio of 1-octane to 1-butanol and the concentration of Ce(NO3)3. The size of the CeO2 nanoparticles decreased as the mass ratio of 1-octane to 1-butanol as well as the concentration of Ce(NO3)3 increased. In addition, we studied the UV absorption properties of the CeO2 nanoparticles by UV-Vis spectroscopy.

Ultrathin manganese films were deposited onto Si(111)-7×7 surfaces by electron-beam evaporation. The solid phase reaction between the manganese thin film and the Si(111) substrate between 300 and 650 ℃ was studied in situ by ultrahigh vacuum scanning tunneling microscopy (STM). The deposited Mn atoms form an ordered nanocluster array on the Si(111) surface at room temperature. When the sample was annealed at 300 ℃, the Mn nanoclusters increased in size and the nanocluster array became disordered. When the annealing temperature reached about 400 ℃ the Mn began to react with the Si and the products consisted of three-dimensional (3D) and tabular islands. The tabular islands are a MnSi compound and the 3D islands are Mn-rich silicides. The MnSi tabular islands were the only product when the sample was annealed at 500 ℃. At an annealing temperature of 650 ℃, the MnSi tabular islands converted into large 3D islands which were likely Si-rich manganese silicides and the destroyed substrate surface reverted to the 7×7 structure through recrystallization.

Cu/γ-Al2O3, Ni/γ-Al2O3, and Cu-Ni/γ-Al2O3 catalysts were prepared using the deposition-precipitation method and the catalytic performances for hydrogen production during dimethyl ether steam reforming(DME SR) were investigated. The structure and surface characteristics of these catalysts were analyzed by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), NH3 temperature-programmed desorption (NH3-TPD), temperature-programmed oxidation (TPO), and transmission electron microscopy (TEM). It was revealed that both copper and nickel were active components during DME SR and there were interactions among Cu, Ni, and γ-Al2O3. Nickel addition improved copper dispersion to obtain small copper crystallites, and strengthened the interaction between copper and γ-Al2O3 so as to prevent copper agglomeration. Copper addition also improved nickel dispersion and the smaller nickel particle size suppressed CH4 formation, which prevented coke formation. Therefore, Cu-Ni/γ-Al2O3 with superior catalytic activity and stability was obtained. During 100 h durability testing, the Cu-Ni/γ-Al2O3 maintained about 95% DME conversion and did not show obvious deactivation.

A series of metal ion-substituted aluminophosphate molecular sieves of MeAPO-5 (Me=Co, Fe, Cu, Zn, Mn) were hydrothermally synthesized. The as-synthesized and calcined samples were characterized by X-ray diffraction (XRD), diffuse reflectance (DR) UV-Vis spectroscopy, thermogravimetric-differential thermal analysis (TG-DTA), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) techniques. The as-synthesized single-phase MeAPO-5 molecular sieves all had high crystallinities. The type of metal significantly influences the states and amounts of the incorporated metal species, as indicated by DR UV-Vis and ICP analysis results. Co2+, Zn2+, Fe3+, and Mn2+ can be incorporated into the framework through the substitution of Al3+, while Cu2+ substitution is difficult. Selective oxidation of cinnamyl alcohol with molecular oxygen over various MeAPO-5 molecular sieves was conducted to probe the effects of the nature and states of metal species on their catalytic performances. CoAPO-5 showed higher catalytic activity and selectivity than the other MeAPO-5 molecular sieves. 1,4-Dioxane should be of the choice of solvent. A decrease in the reaction temperature favors the formation of cinnamaldehyde whereas an increase in the reaction temperature remarkably promotes the epoxidation of cinnamyl alcohol regardless of the occurrence of deep oxidation processes.

The effect of carbon modification on electrocatalytic performance of carbon supported Pd catalysts was investigated. Fourier transform infrared (FT-IR) spectrometer, X-ray photoelectron spectroscopy (XPS) and Boehm titration measurements demonstrate that the contents of O-containing groups and N-containing groups on the activated carbon surface increase via HNO3 and NH4OHtreatment. Transmission electron microscope (TEM) and electrochemical measurements indicate that the treatment of activated carbon with HNO3 can decrease the size of the Pd particles. Thus, the electrocatalytic activity and stability of the carbon supported Pd catalyst for the oxidation of formic acid are enhanced. The treatment of activated carbon with NH4OH has almost no effect on the Pd particles size, however, the content of Pd0 in the Pd/C catalyst enhances, which leads to the further increase in the electrocatalytic performance the Pd/C catalyst.

WC zeolite nanocomposite was synthesized by combining a mechano-chemical approach with the reduction-carbonization technique. We used natural zeolite as a support and ammonia metatungsten as a tungsten source. The pretreated zeolite was mixed with ammonia metatungsten at a n(Si):n(W)=2:1 by a ball miller to produce the WO3/zeolite precursor. The precursor was then reduced and carbonized in a CH4/H2 atmosphere at 1173 K in a furnace for a specific period of time. The product was characterized by X-ray diffraction (XRD), scanning electron microscopy(SEM), and X-ray energy diffusive spectroscopy (EDS). Results showed that the sample was composed of monotungsten carbide, bitungsten carbide, quartz, mordenite, and clinoptilolite. The diameter of the monotungsten carbide particles was found to be about 30 nm and that of bitungsten carbide about 20 nm. The electrocatalytic activity of the sample for p-nitrophenol in a neutral solution was measured using a powder microelectrode. Results show that the sample is electrocatalytically active in a neutral p-nitrophenol solution. The electrocatalytic activity of these samples is better than that of mesoporous tungsten carbide and this is due to the mass fraction of WC and the ratio of w(WC)/w(W2C). These results indicate that a synergistic effect exists between the tungsten carbide and the zeolite.

The nanocomposite Ag/TiO2-ZrO2 possessing high photocatalytic activity was prepared by the sol-gel method combined with temperature-programmed treatment in the presence of the triblock copolymer surfactant EO20PO70EO20 (P123) followed by extraction. The phase composition, structures and morphologies of the nanocomposite Ag/TiO2-ZrO2 were well-characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), N2 adsorption-desorption tests and scanning electron microscopy assisted X-ray energy dispersive spectroscopy (SEM-EDS). Results showed that the silver species in the nanocomposite Ag/TiO2-ZrO2 was metallic Ag0. Moreover, the composite had bimodal pore systems, an orderly distribution of particles and od structure. The average pore diameter was ca 3.6 and 9.0 nm. The microwave assisted photocatalytic degradation of methyl orange on Ag/TiO2-ZrO2 in an aqueous solution was carried out to investigate the catalytic activity. After extraction, the photocatalytic activity under microwave irradiation was found to be more efficient than that under UV irradiation and methyl orange degraded by 81.5% within 90 min. This degradation behavior was better than that of Degussa P25 and TiO2-ZrO2.

Highly dispersed TiO2/SBA-15 photocatalysts were successfully synthesized by solvothermal treatment using titanium n-butoxide (TB) and carboxylate-modified SBA-15 (COOH/SBA-15) as raw materials. The od dispersive carboxyl groups of COOH/SBA-15 coordinated with TB molecules to anchor them. After solvothermal treatment, the TB molecules were transformed into TiO2 nanoparticles and finally formed the TiO2/SBA-15 products. The products were calcined to improve the crystallization of TiO2 and to remove the organic compounds. As-obtained TiO2/SBA-15 photocatalysts were characterized by X-ray diffraction (XRD), nitrogen adsorption, Fourier transform infrared (FI-IR) spectroscopy, and transmission electron microscopy (TEM). Analytical results showed that the as-obtained TiO2/SBA-15 photocatalysts possessed a better mesoporous structure and a larger specific surface area. The highly crystalline anatase TiO2 nanocrystals dispersed well on the surface of SBA-15. RhodamineB (RhB), as a photodegradation target, was used to evaluate photocatalytic performance under UV light irradiation. The as-obtained TiO2/SBA-15 photocatalysts exhibited much better photocatalytic activity compared with the photocatalysts prepared by a post-synthesis impregnation method.

Cu-doped BiVO4 photocatalysts were hydrothermally synthesized and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS), and scanning electron microscopy (SEM). XRD showed that all the photocatalysts have the same single monoclinic sheelite structure. XPS results show that Cu exists on the surface of the BiVO4 catalysts as their stable oxide cation species. An absorption edge red-shift was obtained by DRS studies. The photocatalytic activity was investigated using methyl orange (MO) as a photocatalytic degradation model reactant. Results showed that the Cu-doped catalysts enhanced photocatalytic activities under visible-light irradiation. An enhanced photocatalytic mechanismwas also discussed.

We synthesized Zn2SnO4 nanomaterials by the carbon-thermal evaporation method with Zn, SnO2 and C powder mixture, without using a catalyst, to investigate the controllable synthesis of Zn2SnO4 nanomaterials and to study their optical properties in the ultraviolet region. The structure, and morphology of the as-grown products were characterized by X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM). X-ray photoelectron spectroscopy (XPS) was also used to study the type of binding of the elements onto the product surfaces. Results show that zinc and tin are in the +2 and +4 oxidation states, respectively. We detected two different Zn 2p3/2 binding energies and attributed these to ZnO and Zn2SnO4. The two binding energies of Sn 3d revealed that Sn4+ occupies two distinct sites in Zn2SnO4. Our measured photoluminescence spectrum (PL) at room temperature consists of a broad emission in the ultraviolet region (320-450 nm) and a strong emission in the visible region. The asymmetric ultraviolet emission band can be divided into two emission bands (358 and 385 nm). Compared with the PL spectrum of pure ZnO, the band centered at 358 nmis assigned to the near-band-emission of Zn2SnO4.

Based on micro-electro-mechanical system (MEMS) technology, a miniature high-field asymmetric waveformion mobility spectrometry (FAIMS) sensor chip was designed and fabricated. The chip's dimensions are 18.8 mm×12.4 mm×1.2 mm. It consists of an ionization region, a drift tube, and an ion detection region. In the ionization region, the sample is ionized by a vacuum ultraviolet ion source at ambient pressure. The produced ions were then focused before entering the drift tube under the influence of the electrical field created by the focusing electrodes in the ionization region, which increased the ion signal intensity. A 200 μm thick silicon wafer was etched by inductively coupled plasma (ICP) and then bonded together with two glass plates sputtered with Au/Cr (300 nm/30 nm) to form a rectangular drift tube with dimensions of 10 mm×5 mm×0.2 mm. The ion detection region is a micro Faraday cup, which is made up of three rows of staggered cylinders of 200 μm in diameter and with a 100 μm spacing interval. The Faraday cup can detect positive and negative ions simultaneously. The FAIMS chip was investigated using high-field asymmetric rectangular waveform power with a peak voltage of 364 V at a frequency of 2 MHz and a duty cycle of 30%. Acetone and toluene samples were used to characterize the sensor chip. With a carrier gas flow rate of 80 L·h-1 and by sweeping the compensation voltage from -10 to 3 V at a 0.1 V steps, acetone and toluene spectra were obtained. The FAIMS-MS experiments further show that ions can be separated and filtered by the FAIMS system.

Interactions between hydroxyalkyl ammonium ionic liquids (HyAA ILs) and sulfur dioxide (SO2) were investigated by quantum chemical calculations using first-principles density functional theory. The optimized geometry, charge distribution, and thermodynamic parameters were obtained and used to identify the effective groups in the ILs that absorb SO2. HyAA ILs react with SO2 and form S—N bonds with an average distance of 0.240 nm. This reaction results in charge transfer from ILs to SO2 as well as changes in the S—O bond length and the O—S—O bond angle. The calculated results from the gas and liquid state models indicate that the standard Gibbs free energy change (△G Θ) of the absorption reaction is mainly determined by the geometry of these cations and their molecular weight. The cation structure influences the energy barrier of the absorption reaction and the activation energy (Ea) changes as follows: Ea(secondary)<Ea(tertiary)<Ea(primary). The theoretical results were evaluated against experimental data and the molar fraction values of SO2 for the primary ammonium IL-SO2 system are in od agreement with the experimental results. This work provides an effective method for predicting and verifying the properties of functionalized ILs.

First-principles calculations based on density functional theory (DFT) were used to investigate the adsorption of urea onto a nonpolar ZnO(10-10) surface with the VASP (Vienna ab-initio simulation package) code. The calculation results indicated that urea was favorably adsorbed onto the ZnO(10-10) surface molecularly, and that stable adsorption products were formed through the reaction between nitrogen atom or oxygen atom from urea and zinc atom on the surface. The adsorption energy was -1.48 and -1.41 eV, respectively. The adsorbed urea can dissociate to form an isocyanic radical, an ammonia molecule, and a surface hydroxyl, all of which adsorb onto the surface. The adsorption energy was -1.66 eV.

The adsorption, dissociation, and diffusion of CO on the α-U(001) surface were studied using density functional theory with the generalized gradient approximation (GGA). The calculation results show that a CU3OU2-type molecular chemisorption of CO is favored with adsorption energies of 1.78-1.99 eV. The U atoms of the surface layer are found to move upwards after adsorption coupled with a rumpling of the surface layer. The interaction between the U atoms and a CO molecule results mainly from the population of the CO 2π* LUMO by U electrons and the CO 2π*/5σ/1π-U 6d orbital hybridization. Dissociative adsorption is energetically more favored than molecular adsorption with adsorption energies of 2.71 and 3.08 eVfor the h1(C)+h2(O) and h1(C)+h1(O) (h: hollowsite) dissociative configurations, respectively. The diffusion barriers of C and O atoms between two adjacent threefold hollow sites are found to be 0.57 and 0.14 eV, respectively, which indicates that the on-surface diffusion ofO atoms is more easily achieved than that of C atoms.

The adsorption behaviors of five imidazoline corrosion inhibitors with different alkyl chain lengths on a Fe(001) surface were investigated by molecular dynamics simulation method, and the inhibition mechanism was also discussed in depth. The results demonstrate that the head group of the imidazoline molecule is attached to the metal surface while the alkyl chain deviates from the metal surface. Stable corrosion inhibitor molecule absorption is achieved by self-distortion. Additionally, the combination of corrosion inhibitor and metal surface strengthens with the elongation of the alkyl chain, and the density of the corrosion inhibitor monolayer also increases. As a result, the formed dense corrosion inhibitor monolayer efficiently restrains the diffusion of the corrosive media from the liquid phase to the metal surface, which delays its corrosion. A theoretical evaluation of the corrosion inhibition performance of five corrosion inhibitors agrees well with the experimental results.

All possible geometrical structures of Fe6-xAlx clusters were optimized at the BPW91 level in density functional theory (DFT). The stability and electronic structures as well as magnetic properties of the lowest-energy structures are analyzed. Theoretical results show that iron atoms are brought together, yielding a maximum of Fe—Fe bonds, and aluminum atoms are located around the Fe core with a maximum of Fe—Al bonds. As the number of Al atoms increases, the total magnetic moments of Fe6-xAlx clusters decrease. Natural bond orbital analysis reveals that the hybridization between Fe 4s, Al 3s and Fe 3d results in decreasing the total magnetic moments of Fe6-xAlx clusters.

The geometric and electronic properties of CnAl+ (n=2-12) clusters were investigated using the B3LYP method of density functional theory (DFT). Structural optimization and frequency analyses were performed with the 6-311++G**basis set. Calculation results showed that the ground state of the CnAl+ clusters was a linear or polyline structure with a terminal aluminum atom, and an aluminum atom was inserted into the Cn ring to form a new ring structure or an aluminum atom bonded to one side of the monocyclic Cn ring. With an increase in n, the total average molecular bond length gradually approached 0.138 nm. We obtained stability information by an energy analysis of the ground state.

Vanadium-doped anatase TiO2 was prepared by a sol-gel method while V2O5 and ethanol were used as vanadium precursors. UV-Vis transmissivity spectra revealed that the spectral response of the V-doped TiO2 shifted to the visible light region. The optimum vanadium content was 1.0% (molar fraction). Furthermore, we performed first-principles calculations on the electronic band structure of the V-doped anatase TiO2 and explained some experimental phenomena. Our results indicate that the bandgap becomes narrow and the TiO2 spectral response increases with the doping concentration increases. The valence band and the conduction band are so close that the cavities and electrons easily recombine. Additionally, strong correlation of the electron of the V 3d orbital to the Ti 3d orbital electron results in the low dispersibility of the electron on the V 3d orbital. Therefore, the photocatalytic activity of V-doped TiO2 becomes weak with the increasing of doping concentration. When the optimum phosphorus content in our calculation is 6.25% (molar fraction), the red shift of TiO2 light absorption band is the largest, which is in agreement with the experimental trend.

Using density functional theory, time-dependent density functional theory and natural bond orbital analysis, we designed D5 analogue molecules, which are superior to the organic dye D5 for use in dye-sensitized solar cells. The symmetric introduction of the electron donating substituents (—OH,—NH2,—OCH3) to the electron donating groups of the D5 skeleton raises the energy level of the lowest unoccupied molecular orbital (LUMO) and causes a red-shift in the absorption spectra. These changes enhance the ability of the dye molecules to capture photons from solar radiation as well improving the driving force for electron injection from the dye molecule's excited state to the TiO2 electrode. The symmetric introduction of electron-acceptors (—CF3,—F,—CN) to the skeleton of D5molecules red-shifts the absorption spectra of the dye molecules greatly, allowing for more efficient use of solar energy. Considering the increase in the LUMO energy level and the red-shift in the absorption spectra, the designed molecules D516, D536 and D537 are superior analogue molecules of D5, of which D516 is the best. By only considering the absorption spectra red-shift, the designed molecules D565, D567 and D568 are superior analogue molecules of D5. Among these, the absorption spectrum of D565 is expected to better match the solar radiation spectrum. The six selected D5 analogues all have D-π-A (donor-conjugate π bridge-acceptor) structures. For these molecules, the transitions from the highest occupied molecular orbital to the LUMO arising from optical excitation are all π-π* intramolecular charge transfer transitions. Their electronic absorption spectra lie in the near-ultraviolet-visible light zone. Compared with D5, D516 and D565 are more applicable for use in DSSC as metal-free organic dye molecules.

Possible configurations and optical properties of a cucurbit[7]uril (CB7) and riboflavin (VB2) inclusion compound were investigated by density functional theory (DFT).Acomparison was made among the different structures by an analysis of the interaction between the host and guest molecules. The results indicate that riboflavin sits on top of the cucurbit[7]uril molecule with a couple of hydroxyls inserting into the cavity to formH-bonds.We verify theoretically that the inclusion reaction is an exothermal reaction, which supports the findings from the experiment very well. The sequence of stability for the possible inclusion complexes is strong evidence that the interaction between the guest and host molecules and the distortion of the guest and host molecules both contribute to the stability. The bonding energy and stability should be distinguished conceptually. The time-dependent DFT method was used in the excited state calculations to explore the photochemical properties of the inclusion compounds. The component difference for the excited orbitals in the different inclusion complex configurations was compared theoretically. The results show that cucurbit[7]uril causes a red-shift absorption and fluorescence quenching for riboflavin after host-guest inclusion, which strongly support the experimental data.

Thieno-tetrathiafulvalene derivatives show great potential for use as organic field effect materials. We investigated the orbital energy levels, ionization potentials (IP), electron affinities (EA), and the reorganization energy (λ) of a series of fluoride substituted thieno-tetrathiafulvalene derivatives (c2FT, t2FT, and 4FT) using density functional theory at the B3LYP/6-31G(d,p) level. We, therefore, calculated the carrier mobilities of their dimers to investigate their charge transport properties. Furthermore, the effects of substituent position and the stacking mode on the charge transport characteristics were also discussed. Results show that the substituent position of fluorine atom slightly affects the mobility of the dithieno-tetrathiafulvalene derivatives, and that fluorination lowers their electron-donating abilities. These calculations are helpful for the design and synthesis of potentially photoelectric functional materials with high performance and stability.

Divalent silicon species (silylenes) corresponding to carbenes in organic chemistry are key intermediates in numerous thermal and photochemical reactions of organosilicon compounds. Considering the electronic characteristics of this class of compounds, the higher homologues of the nitro-heterocyclic silylenes are also of interest and have been studied experimentally and theoretically. This prompted us to take a closer look at the chemical behavior of nitro-heterocyclic silylenes on a theoretical basis. The insertion reactions of nitro-heterocyclic unsaturated stable silylenes (1, 3, 4) and nitro-heterocyclic saturated silylenes (2, 5) into HF, H2O, and NH3molecules were performed using density functional theory (DFT) at the B3LYP/6-311++G(d,p) level. The insertion mechanisms were investigated and results from various reactions were compared. The results indicated that the insertion reaction mechanisms of heterocyclic silylenes and HX were similar to those of simple silylene. From the reaction energy barrier and the reaction enthalpy, the insertion reaction could occur easily according to the following order: HF>H2O>NH3. The reaction activities of saturated silylenes were stronger than those of unsaturated silylenes. Therefore, it is difficult to synthesize heterocyclic saturated silylenes.

Electronic structures of pyrites containing vacancies were calculated using a first-principles plane-wave pseudopotentials method. The influence of vacancy defects on pyrite flotation behavior is discussed. Results show that sulfur vacancy has little effect on volume while iron vacancy results in a cell volume expansion of 1.29%. The presence of vacancy defects mainly affects the electronic structure near the Fermi level while new energy levels are introduced into the forbidden band and this is caused by atoms close to vacancies. The presence of vacancies increases the Fermi level, which is undesirable in pyrite flotation. The calculation of effective mass indicates that the presence of vacancies increases the localization of electrons located at the bottom of the conduction band. Mulliken bond population analysis of atoms shows that the covalence of the S—Fe bond is greater than that of the S—S bond and that the presence of vacancies results in an increase in the covalence of bonds between the atoms close to the vacancies, which is beneficial to pyrite flotation. We conclude that the presence of vacancies adversely affects pyrite flotation when both the influence of vacancies on the Fermi level and the covalence between atoms are considered.

The facilitative effects of four bioactive extracts from Cornu Cervi Pantotrichum, a valuable traditional Chinese medicinal herb, on the growth of two kinds of intestinal diagnostic flora were investigated by the microcalorimetry. By analyzing the power-time curves, quantitative parameters, such as the growth rate constant (k), maximumheat output power (Pmax), peak time of maximumheat output power (tp), and effective power (E), were obtained to characterize the interactions of the extracts and Bifidobacterium adolescentis, which benefits the host animal by improving its intestinal microbial balance. The potential pharmacological action of the four bioactive extracts was analyzed to determine the strongest facilitative extract from Cornu Cervi Pantotrichum. The sequence of facilitative activity for the different extracts was: n-butanol > diethyl ether > chloroform > ethyl acetate (EtAc). The inhibitory effects of n-butanol extraction on the growth of Staphylococcus aureus, a harmful bacterium, were investigated. Results indicated that the concentration (200-1200 μg·mL-1) of n-butanol extraction notably affected the growth of this fungus. Furthermore, the value of tp increased as the concentration of n-butanol used in the extraction increased. However, k and Pmax decreased as the concentrations of the drugs increased. The results show that microcalorimetry is sensitive, accurate, rapid and convenient. This method can also be applied in real time and online to monitor the process of bacterial growth and can be used to screen the bioactive extracts of Cornu Cervi Pantotrichum. This method is also useful in providing some suggestions for the study of pharmacodynamic action.

First-principles were used to investigate hydrogen adsorption and diffusion on clean and Al doped Mg2Ni(100) surfaces. The calculation results show that H prefers to adsorb onto Mg-Ni bridge sites and Mg-Mg bridge sites on a clean Mg2Ni(100) surface, and their adsorption energies range from1.19 to 1.52 eV. For the Al doped Mg2Ni(100) surface, H prefers to adsorb onto the Al-Ni, Mg-Ni, Mg-Al bridge sites and the adsorption energies range from 0.10 to 0.29 eV. The results indicate that the Al doped Mg2Ni(100) surface reduces the adsorption energy for hydrogen. The transition state calculation shows that the energy barrier for H that diffuses from the clean and the Al doped Mg2Ni(100) surface to the subsurface is 0.59 and -0.04 eV, respectively. Doping the Mg2Ni(100) surface with Al weakens the interaction between H and the surface, and also reduces the barrier for hydrogen diffusion, which may be one reason for improving the kinetic properties of hydrogen adsorption for Mg2Ni alloy doped with Al.

Microscale V-shaped impact pits are formed on copper surfaces after sandblasting. After surface oxidation, the whole copper surface is uniformly and completely covered by petal-like CuO nanosheets. Micro-and nanoscale structures are fabricated by a combination of sandblasting and surface oxidation, which leads to a high water contact angle of 161° and an ultra-low water roll angle of 1° for the surface after fluorination. Water condensation is difficult at low temperatures as heat transfer between the surface and water droplets is greatly reduced on these surfaces. This is thought to be the main reason for the improvement in ice resistance of the superhydrophobic copper surface. Superhydrophobic copper surfaces with excellent anti-icing performance can be widely used in many fields such as in heat exchange and in products operating at low temperatures. Such a facile technique is expected to be a feasible method for the industrial fabrication of superhydrophobic surfaces on other engineering materials.