In this work, we describe two synthetic procedures for preparing palladium doped 25-atom nanoclusters (referred to as Pd₁Au₂₄(SR)₁₈, where ―SR represents thiolate, R=C₂H₄Ph). Pure Pd₁Au₂₄(SC₂H₄Ph)₁₈ nanoclusters are isolated by solvent extraction and size exclusion chromatography. Mass spectrometry and optical spectroscopy analyses demonstrate that the Pd₁Au₂₄(SC₂H₄Ph)₁₈ nanocluster adopts the same core-shell structure as that of the homo ld Au₂₅(SC₂H₄Ph)₁₈ nanocluster, that is, a Pd- or Au-centered icosahedron surrounded by six Au₂(SR)₃ “staple”-like motifs. Similar doping behavior has also been observed in 38-atom M₃₈(SR)₂₄ (M: metal) nanoclusters, indicating the unique behavior of Pd dopant being preferentially located in the icosahedral center. The catalytic activity of Pd₁Au₂₄(SC₂H₄Ph)₁₈ has also been evaluated for the selective hydrogenation of α,β-unsaturated ketone (e.g., benzalacetone) to α,β- unsaturated alcohol, and a 42% conversion of benzalacetone is attained.

Polymeric surfactants are widely used in many fields. Their aggregation behavior is different from that of small molecule surfactants because of complex configurations and large molecular weights. The studies of aggregation behavior at the micro-level can guide applications and therefore, many researchers have focused on theoretical investigations. With the recent advances in computer simulations, the study of surfactant aggregation behavior in aqueous solutions at the micro- or meso-level has been successfully undertaken. Based on our recent work, we review the aggregation behavior of polymeric surfactants by dissipative particle dynamics (DPD) and mesoscopic dynamics (MesoDyn). This paper especially introduces research about the phase behavior of polymeric surfactants as well as their interactions with low molecular weight surfactants. This method can directly provide the process of phase separations and changes in the conformation of the aggregates, which are not observable in macro- experiments. This method has the potential to complement and guide experimental methods.

We developed a reduced kinetic model for toluene reference fuel (TRF) including 70 species and 196 reactions for homogeneous charge compression ignition (HCCI) combustion. The low temperature reaction scheme for the TRF was based on the existing low-temperature reaction mechanism developed by Tanaka for primary reference fuel (PRF) oxidation. We added skeletal reactions for PRF oxidation to a reduced toluene sub-mechanism. The high-temperature reaction mechanism was mainly from the previous work of Patel and an important TRF reaction [H+O₂+M=O+OH+M] was added. Validation of the ignition delay time was performed for single-component, two-component and three-component fuels and the results were satisfactory for HCCI engine conditions. A comparison of various experimental data available in the literature, including shock tube tests and HCCI engine experiments, shows that the present TRF mechanism performs well. A sensitivity analysis at the moment of maximum heat production shows that the reaction of phenol radicals (C₆H_<5) with O₂ is more sensitive as the pressure increases. Formaldehyde (HCHO) is a very important intermediate species and should not be neglected.

Based on mimicing the N, O coordination environment of the active center of vanadium haloperoxidase (V-HPOs) and the hydrogen-bond interaction between the active center and amino acid residues or water molecules, we designed and synthesized two kinds of oxidovanadium complexes: (C₃H₅N₂)₂[(VO)₂(μ₂-C₂O₄)(C₂O₄)₂(H₂O)₂] (1) and (VO₂)₂(μ₂- C₂O₄)(C₂H₄N₂)₂ (2). We determined their structures by X-ray single crystal diffraction. The crystal structure analysis indicated that the coordination environments of those oxidovanadium complexes were similar to the active center of vanadium haloperoxidase, and there seemed to be a mimicing α-helix structure in the three-dimensional packing structure of the complexes. Additionally, by studying the bromination reaction activity we found that the oxidovanadium complexes had an upper activity during the mimic catalytic process.

The solubilities of adefovir dipivoxil (AD) in saccharin (SAC) ethanolic solutions at different temperatures and in SAC aqueous solutions at constant temperature were determined to investigate the thermodynamic characteristics of AD-SAC co-crystals. The solubility products (K_sp), complexation constants (K₁₁), and Gibbs free energy (ΔG⁰) were calculated. Ternary phase diagrams of the AD-SAC- ethanol systems at various temperatures were established. We demonstrate that temperature has significant influence on the K_sp and K₁₁ in ethanolic solution. K_sp decreased and K₁₁ increased with a decrease in temperature. Dissolution of the co-crystals in ethanol is an endothermic process. Co-crystal formation is a spontaneous and endothermic process. A decrease in temperature favors complexation between the AD and SAC in ethanol. In aqueous solutions of SAC, the solubility of AD shows a three- stage profile with a platform.

Grand canonical Monte Carlo (GCMC) simulations were performed to study the stepped behaviors of carbon dioxide adsorption in the following five isoreticular metal-organic frameworks (IRMOFs): IRMOF-1, -8, -10, -14, -16. The simulation results show that the stepped phenomenon occurs easily when the temperature is low and the pore size is large for these IRMOFs. The critical pressure and temperature where the stepped behavior occurs show a linear relationship with the pore size. The results also further indicate that the electrostatic interaction between CO₂ and CO₂ molecules plays a dominant role on the stepped behavior. All these findings may provide useful information for the design and modification of MOFs for the adsorption and separation of carbon dioxide in gas mixtures.

Based on the Green′s function method and the Landauer-Büttiker formula, we studied the electronic transport properties of a graphene heterojunction. This was a Z-shaped graphene nanoribbon (GNR), which was connected by zigzag graphene nanoribbon leads. We show that the conductance of the Z-shaped GNRs is highly sensitive to the shape and size of the heterojunctions. The charge density is strongly localized on the zigzag edge sites of the leads and thereby a conductance dip or gap results at the Fermi energy. By varying the width of the graphene ribbons between the junctions, we found many more resonant peaks in the conduction because of the quasi-bound states. The number of resonant peaks has little to do with the length of the graphene ribbons between the junctions. Importantly, we show that in the low-energy region the electrons retain their ballistic transport characteristic in the width uniformity of Z-shaped GNRs with included angle θ of 60° or 150° turns. These findings show that the Z-shaped GNRs can be selected for future ballistic device applications.

The mechanism of the reaction between HOSO and NO was investigated at the B3LYP/6-311++G(d,p) level of theory. The geometries of the reactants, intermediates, transition states, and products were optimized. The intrinsic reaction coordinates (IRC) were traced and the connecting relationship between the transition states and the reactants, products were confirmed. The single point energies of the species were corrected at the CCSD(T) /6-311++G(d,p) level of theory. The reaction rate constants were calculated over a temperature range of 200-3000 K using classical transition state theory (TST) and canonical vibration transition state theory (CVT) combined with a small-curvature tunneling (SCT) correction. The results showed that the HOSO+NO reaction occurs in both the singlet and triplet reaction channels. The singlet reaction channel is dominant, and HNO and SO₂ are the main products. The chemical bond changes in the main reaction channel were analyzed by a topological analysis of the electron density.

On the basis of Templeton′s experiment (West, N. M.; et al. Organometallics 2008, 27, 5252), the mechanisms of the main and the side reactions between (Cl-nacnac)Pt(H) (Cl-nacnac: bis(N-aryl)- β-diiminate) and a terminal alkyne were investigated by density functional theory. Our study shows that the 1,2-insertion of t-BuC≡CH into the Pt―H bond generates the main products and that C―C bond formation is the rate-determining step. The 2,1-insertion of t-BuC≡CH into the Pt―H bond generates the by- products and alkyne insertion is the rate-determining step. Based on the mechanisms of the main and side reactions the presence of the main product and the by-product could be explained. We found that the main product is thermodynamically controlled while the side product is kinetically controlled.

We investigated the mechanism of the AuCl₃-catalyzed synthesis of highly substituted furans from 2-(1-alkynyl)-2-alken-1-ones with nucleophiles using the density functional theory (DFT) with B3LYP function, and obtained the optimal pathway. The rate-determining step of the cyclization is H-migration from the hydroxy group to a ligand Cl of AuCl₃ with a 49.3 kJ·mol^-1 energy barrier. The calculated results show that the ligand Cl of AuCl₃ plays an important role in the reaction, which stabilizes the catalyst and is also directly involved in the reaction. The active energy of proton transfer decreases from 71.5 to 49.3 kJ·mol^-1 by assisting the proton transfer. In addition, the reason why HBF₄ cannot catalyze the cyclization of 2-(1-alkynyl)-2-alken-1-ones is also discussed in this work. The theoretical results are consistent with the experimental observations.

Density functional theory (DFT) B3LYP/6-31G^* method was used to optimize the geometrical structures of a series of heteroaromatic molecules with carbazole chromophores. The second-order nonlinear optical (NLO) properties and electronic spectra were then studied by finite field (FF) and time-dependent DFT (TD-DFT) methods at the 6-311G^** level. The results showed that the polarizability α and the second-order NLO coefficient β values of all molecules were influenced greatly by the change of the push-pull electronic ability of the carbazole substituent groups and the introduction of heteroaromatic. When the pull electronic nitro and the push electronic hydroxyl were linked by carbazole substituent groups respectively and the furan heterocycle was introduced, the β values decreased (blue-shifted) with an increase in the maximum absorption wavelengths λ_max of the molecules. The “nonlinear-transparency tradeoff” conflict was avoided because of the high second-order NLO responses and od transparency. All the compounds may have potential application in the development of NLO materials.

The ground state (S₀) structures of 3(5)-(9-anthryl) pyrazole and its derivatives were obtained using the density functional theory (DFT) B3LYP/6-31G(d) method. The first singlet excited state (S₁) structures were optimized using the singlet-excitation configuration interaction (CIS)/6-31G(d) method. The absorption and emission spectra were then evaluated using the time-dependent density functional theory (TD-DFT) B3LYP method with the 6-311++G(d,p) basis set. Our calculation results reveal that for all the derivatives (electron-withdrawing groups or electron-donating groups) the calculated absorption and fluorescence emission wavelength values all show red shifts compared with the parent 3(5)-(9-anthryl) pyrazole. We also find that compared with the parent 3(5)-(9-anthryl) pyrazole, the derivatives with ―R=―BH₂, ―CCl₃, ―CHO, ―NH₂ are od candidates for longer absorption wavelength materials and for longer fluorescence emission wavelength materials.

Redox potentials are of importance in understanding the charge/electron transfer processes involved in nucleic acids. In this study, the protocol of the B3LYP/6-311++G(2df,2p)//B3LYP/6-31+G(d) in gas phase and the HF-COSMORS/UAHF for the solvation energy calculations at the HF-CPCM/UAHF re-optimized solution geometries in aqueous solution, as implemented in the Gaussian 03 programs, has been established to predict the redox potentials of the aromatic compounds in aqueous solution. In comparison with the 82 experimental redox potentials, the root mean square deviation (RMSD) is only 0.124 V. This scheme has been employed successfully to calculate the redox potentials of various nucleobases and the metabolites. The structural and charge/electron transfer impact on the redox potentials was discussed. The implications to the design of new redox-active nucleobase derivatives were suggested.

The electrocatalytic performances of a Vulcan XC-72 carbon black supported Pd (Pd/XC) catalyst and a macroporous carbon supported Pd (Pd/MC) catalyst for formic acid oxidation in a direct formic acid fuel cell were investigated and compared. This was carried out using X-ray energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) spectroscopy, Raman spectroscopy, and electrochemical techniques. The cyclic voltammograms indicate that the main peak potentials for the oxidation of formic acid at the Pd/XC and Pd/MC catalyst electrodes are similar and they are located at about 0.15 V. However, the peak current density of the Pd/MC catalyst electrode is about 30% larger than that of the Pd/XC catalyst electrode. The chronoamperometric curves indicate that the peak current density at the Pd/MC catalyst electrode at 6000 s is about 38% larger than that at the Pd/XC catalyst electrode. These results show that the electrocatalytic activity and stability of the Pd/MC catalyst for the oxidation of formic acid are better than those of the Pd/XC catalyst. Because the average size and relative crystallinity of the Pd particles in the two catalysts are similar, the reason for the better electrocatalytic performance of the Pd/MC catalyst could be only attributed to its larger pore diameter and higher conductivity because of its high extent of MC graphitization.

We synthesized LiFePO₄ directly by a solvothermal method at low temperature and then a heat treatment was carried out to give a LiFePO₄/C composite for using as a cathode in lithium ion battery. The crystal structure and the charge-discharge performance of the prepared samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and galvanostatic charge-discharge testing. The results indicated that the LiFePO₄ synthesized at low-temperature (120 °C) with glycerol as a solvent had a single olivine-type crystal structure and a spindle-shaped morphology with a very narrow size distribution. After heat treatment, a LiFePO₄/C composite with excellent charge-discharge performance was obtained and the spindle morphology of the sample was intact. Galvanostatic charge-discharge tests showed that the prepared LiFePO₄/C cathode had an initial discharge specific capacity of 147.2 mAh·g^-1 at 0.1C at room temperature and it was 136.3 mAh·g^-1 after 50 cycles. The average discharge specific capacities of LiFePO₄/C at 0.2C, 0.5C, and 1C were about 130, 120, and 108 mAh·g^-1, respectively.

We prepared an electrode consisting of NiCo₂O₄ nanowire arrays that stand freely on nickel foam by a template-free growth method. Its morphology was determined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The phase structure of the nanowires was analyzed by X-ray diffraction (XRD). The supercapacitance of the electrode was investigated by cyclic voltammetry, galvanostatic charge-discharge testing, and electrochemical impedance spectroscopy. The results showed that the nanowires were nearly vertical grow on and densely cover the nickel foam substrate. The nanowires have diameters around 500-1000 nm and lengths up to around 10 μm. The NiCo₂O₄ nanowire arrays have a specific capacitance of 741 F·g^-1 and this value is 655 F·g^-1 after 420 charge-discharge cycles. Electrochemical impedance spectroscopy measurements showed that the charge transfer resistance was only 0.33 Ω and this increased by only 0.06 Ω after 420 cycles.

Several microporous carbons were prepared by polyfurfuryl alcohol-impregnation and impregnation-acetonitrile chemical vapor deposition (CVD) using zeolite HY as a template, denoted as PFA carbons and AN carbons, respectively. These were used as electrode materials for supercapacitors. X-ray diffraction (XRD) patterns show that the structural regularity of the zeolite was well-replicated by the carbon structures prepared by impregnation-CVD. X-ray photoelectron spectroscopy (XPS) confirmed that the AN carbons possess abundant nitrogen-containing groups because of the CVD of acetonitrile. The prepared carbons were typical microporous materials as determined by N₂ adsorption/desorption test and they had a high BET surface area and narrow pore size distribution. Electrochemical tests showed that the AN carbons had higher capacitance because of their evident pseudo-capacitance from the nitrogen- containing groups. AN8 had a high capacitance up to 210 F·g^-1. The capacitance retention ratio of the AN carbons were determined to its electric conductivity and mesoporosity.

Spherular-Co₃O₄ particles were synthesized on graphite electrode surface by ammonia-evaporation-induction. Its electrooxidation catalytic behavior for sulfide ions in an alkaline solution was investigated by electrochemical measurements such as potentiodynamic scanning and potentiostatic polarization. We found that high catalytic activity and the highest current density of 580 mA·cm^-2 were obtained at -0.40 V. In addition, its catalytic performance was stable during potentiostatic polarization. Electrochemical impedance spectroscopy (EIS) indicated a low charge transfer resistance, which explained the high catalytic activity from the viewpoint of electrochemical kinetics.

We studied electroless Ni-B plating with sodium borohydride as the reductant by linear sweep voltammetry. The effects of bath solution composition and operating conditions on the cathodic reduction and anodic oxidation were studied. Increases in the concentrations of nickel acetate and sodium borohydride accelerated the reduction of Ni²⁺ and the oxidation of BH₄^-, respectively. Ethylenediamine, sodium hydroxide, thiourea and saccharin sodium inhibited both the cathodic and anodic reactions to varying degrees. Additionally, sulfur in the additives promoted the dissolution of nickel. High temperature was beneficial to both the cathodic reduction and anodic oxidation.

Cyclic voltammetric and chronoamperometric methods were used to study the initial stage of Au electrodeposition on an indium tin oxide (ITO) surface. The nucleation process was controlled by the diffusion of [AuCl₄]^-. The cyclic voltammetry curves showed that the electrochemical reduction included two steps which were [AuCl₄]^-→ [AuCl₂]^-, and [AuCl₂]^- → Au. Only one reduction peak was observed when the scan rate was comparatively slow and this peak separated into two peaks when the scan rate was increased. This phenomenon resulted from the disproportionation of [AuCl₂]^- during the electrodeposition process. Chronoamperometry also proved the two step reaction mechanism and the diffusion coefficient of [AuCl₄]^- was calculated to be 1.3×10^-5 cm²·s^-1. From the theoretical nucleation curves, an instantaneous three-dimensional nucleation mechanism was proposed for the nucleation of ld on ITO. Au electrodeposits were observed by field emission scanning electron microscopy (FE-SEM). SEM images of the electrodeposits showed that the morphology of the ld deposits was affected by the electrochemical deposition potential and time.

The inhibitive action of a sorbitol/diethylenetriamine condensation (SDC) product toward carbon steel corrosion in saturated Ca(OH)₂ solution containing 3.5% NaCl was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), surface morphological observations, and quantum chemical calculations. The results indicate that the addition of SDC can effectively decrease the corrosion current densities of the carbon steel and increase the pitting corrosion potential suggesting that the local corrosion induced by Cl^- is strongly restricted by the inhibitor, which acts as a mixed type inhibitor. In the studied concentration range, the inhibition efficiency increased with an increase in inhibitor concentration. The overall inhibition behavior of SDC is attributed to the stabile adsorption film formd by the dominantly physical adsorption on the carbon steel surface according to the Langmuir adsorption isotherm.

The effects of three newly synthesized alkylimidazolium based ionic liquids: 1-butyl-3- methylimidazolium hydrogen sulfate ([BMIM]HSO₄), 1-hexyl-3-methylimidazolium hydrogen sulfate ([HMIM]HSO₄), and 1-octyl-3-methylimidazolium hydrogen sulfate ([OMIM]HSO₄), on the corrosion inhibition of copper in 0.5 mol·L_-1 H₂SO₄ solution were investigated using potentiodynamic polarization and electrochemical impedance spectroscopy. All the measurements show that these alkylimidazolium ionic liquids are excellent inhibitors for copper in sulfuric acid media and the effectiveness of these inhibitors decreases as follows: [OMIM]HSO₄>[HMIM]HSO₄>[BMIM]HSO₄ at the same concentration. Potentiodynamic polarization studies indicate that the three inhibitors are mixed type inhibitors and that both the cathodic and anodic processes of copper corrosion are suppressed. The electrochemical impedance results were evaluated using an equivalent circuit in which two constant phase elements (CPE) were offered for these systems with two time constants. Changes in impedance parameters (charge transfer resistance and double layer capacitance) with the addition of the inhibitors also suggest that these imidazolium based molecules act by adsorbing at the copper/solution interface. The adsorption of these imidazolium based compounds on the copper surface in an acidic solution is found to fit the Langmuir adsorption isotherm. Thermodynamic calculations reveal that the adsorption of inhibitors on the metal surface occurs by a physisorption-based mechanism involving a spontaneous process.

A novel photo-sensitive telechelic polymer——coumarin-containing poly(4-vinylpyridine) (C- P4VP) was prepared using 4-vinylpyridine as a monomer, azodiiso-butyronile (AIBN) as an initiator, and coumarin-containing disulfides (C-S-S-C) as a chain transfer agent in the presence of tributylphosphine (Bu₃P)/H₂O. The polymer was characterized by Fourier transform infrared (FTIR) spectroscopy, ¹H nuclear magnetic resonance (¹H-NMR), and gel permeation chromatography (GPC). We found that the telechelic polymer can form polymer micelles in aqueous solutions at various pH values (pH=3-6). Additionally, when lowering the acidity of the aqueous solution, the polymer micelles gradually compacted and the degree of coumarin photo-dimerization decreased initially and then increased within a similar irradiation time.

A fatty acid disulfonate anionic gemini surfactant was prepared and the structure of the surfactant was characterized by ¹H-NMR. Hydrophobically associating polyacrylamide was prepared according to a procedure from literature. The interaction between the hydrophobically associating polyacrylamide (HAPAM) and the anionic gemini surfactant was studied by surface/interfacial tension, apparent viscosity, and atomic force microscopy (AFM). Experimental results show that HAPAM can form a network structure in the aqueous solution by self assembly. Mixed micelles are formed by the interaction of gemini surfactant micelles and the hydrophobic microdomain of the hydrophobically associating polyacrylamide in aqueous solution, which plays a remarkable role in the surfactant and polymer assembly. Mixed micelles can enhance the inter- or intra-molecular association between the polymer molecules and the surfactant, which increases the strength of the network formed by the hydrophobically associating polyacrylamide. The apparent viscosity of the solution increased by the addition of the gemini surfactant. When the addition of the gemini surfactant exceeded a certain amount, the association between the hydrophobic groups of the polymer decreased and the network formed by hydrophobically associating interaction was weakened by the surfactant micelles, which led to a decrease in solution viscosity. The polymer also largely influenced the interfacial properties of the gemini surfactant, especially the dynamical interfacial tension. A high polymer concentration led to an increase in the time required to reach equilibrium.

Ethylenediamine-modified magnetic chitosan nanoparticles (EMCN) were prepared and used for the adsorption of Acid Orange 7 (AO7) and Acid Orange 10 (AO10) from aqueous solutions. Magnetic chitosan nanoparticles were prepared by adding a basic precipitant NaOH solution to a W/O microemulsion system containing cyclohexane/n-hexanol, chitosan and ferrous salt. This was then modified with ethylenediamine to increase the amine content and to improve the adsorption capacity. Transmission electron microscopy showed that the EMCN was essentially monodispersed and had a main particle size distribution of 15-40 nm. Adsorption experiments indicated that the maximum adsorption capacity was at a pH of 4.0 for AO7 and a pH of 3.0 for AO10. Because of the small diameter and the high surface reactivity of EMCN, the adsorption equilibrium for both dyes was reached very quickly. The equilibrium experiments fitted the Langmuir isotherm model well and the maximum adsorption capacities of 3.47 and 2.25 mmol·g^-1 were obtained for AO7 and AO10, respectively. We estimated the thermodynamic parameters and accordingly the adsorption process was found to be spontaneous and exothermic. Additionally, we regenerated EMCN with an NH⁴OH/NH⁴Cl solution (pH 10.0) and the regenerated material was used to readsorb the dyes.

Sulfonated carbon nanotubes (CNTs)/activated carbon composite beads were obtained by suspension polymerization, carbonization, activation, and further sulfonation using the diazonium salt coupling method. Adsorption of low density lipoprotein (LDL) was explored with these composite beads. The results showed that the composite beads had od sphericity, smooth surface, developed mesopores and were sulfonated by p-aminobenzenesulfonic acid. With the increase of CNTs mass ratio, the adsorption capacity of LDL increased. When the CNTs mass fraction was 45%, the amount of LDL adsorption reached 6.564 mg·g^-1 and was 3.3 times as large as that of the beads without CNTs. Therefore, the composite beads have od prospects as LDL adsorbents in hemoperfusion.

We synthesized a series of micro/mesoporous composites of S-β-MCM41(c), P-β-MCM41(c), P-ZSM-MCM41(c), P-ZSM-C through a two-step crystallization process. During this process, the microporous zeolite precursor solution (S) or the zeolite powder (P) was first synthesized and treated with NaOH solution with different concentration (c), and then the mesopores were induced by hexadecyltrimethyl- ammoniumbromide (CTAB) as a soft template or mesoporous carbon as a hard template. The effects of the type of inorganic precursor, the base concentration, and the type of mesoporous template on the structure and property of the micro/mesoporous composites were investigated. The results of X-ray diffraction (XRD), transmission electron microscopy (TEM), and nitrogen adsorption-desorption isotherms showed that the products contained micropores and mesopores, simultaneously. The CO₂ adsorption capacities of these micro/mesoporous composites were obviously improved compared to the pure microporous or mesoporous materials. Among them, P-ZSM-MCM41(2) had the highest CO₂ adsorption capacity of 1.51 mmol·g^-1, which was almost twice that of the original ZSM-5.

Ni-Co bimetallic catalysts supported on commercial γ-Al₂O₃ modified with La₂O₃ were prepared by conventional incipient wetness impregnation for biogas reforming. The catalysts were characterized using temperature-programmed hydrogenation (TPH), temperature-programmed oxygenation (TPO), temperature-programmed surface reaction (TPSR), temperature-programmed desorption (TPD), and a pulse experiment. During biogas reforming the surface carbon species on Ni-Co/La₂O₃-γ-Al₂O₃ originated mainly from the cracking of CH₄ and the contribution of CO₂ was insignificant. Cracking of CH₄ results in three carbon species of C_α, C_β, and C_γ, which have different reaction activities. During the reaction, the amount of C_α decreased but C_β and C_γ increased. In addition, C_γ could be changed into inactive graphite carbon. The activation of CH₄ and CO₂ was mutually promoted in the reforming reaction. It was revealed that the controlling step for biogas reforming over the Ni-Co/La₂O₃-γ-Al₂O₃ catalyst could be the reaction of the surface species of O with C to form CO or with CH_x to give CH_xO followed by the formation of CO and adsorbed H.

Pd-Cu/activated carbon catalysts were prepared by wetness impregnation and their performance in the room-temperature catalytic oxidation of the pulse reaction of carbon monoxide were investigated using simulated cigarette smoke gas consisting of 4.4 CO-4.2 H₂O-19.2 O₂-72.2 He (volume fraction, %). The effect of different activated carbon supports on catalytic performance was investigated in detail. The results show that at room temperature the order of catalytic performance for CO oxidation is: the catalyst supported on coconut activated carbon (CAC)2+ and Pd⁰ are also present on the surfaces of the CAC and WAC catalysts but only Pd²⁺ is present on the surface of the SAC catalysts, which results in better catalytic activity for SAC than that of the CAC and WAC catalysts. When the ternary composite filter was prepared by inserting the catalyst between the cigarette filter and the acetate filter rod, the smoking tests showed that the amount of CO in the main cigarette smoke decreased noticeably. The SAC catalyst reduced CO by 25.4% when the amount of Pd in the catalyst increased to 3.4% (w).

Pt-Ni alloy catalysts with different atomic ratios were deposited on CMK-5 (carbon replicated from SBA-15 silica) by NaBH₄ reduction. X-ray diffraction (XRD) suggests alloy formation between Pt and Ni. X-ray photoelectron spectroscopy (XPS) shows that Pt-Ni/CMK-5 (5:1) has more detectable oxidized Ni. More metallic Pt is present on Pt-Ni/CMK-5 (5:1) (atomic ratio) than on Pt/CMK-5. Oxidized Ni species, such as NiO, Ni(OH)₂， and NiOOH, favor the adsorption of methanol and the dissociation of methanol from the surface of Pt. Cyclic voltammetry shows that Pt-Ni/CMK-5 (5:1) has the highest specific activity among the as-made catalysts and its electrochemical active area is 63.9 m²·g^-1. It has more resistance to CO poisoning than Pt/CMK-5.

We prepared a new crystalline nonlinear optical coordination compound, benzyltriethylamine bis (2-thioxo-1,3-dithiole-4,5-dithiolato) aurate(III) (BTEAADT). A BTEAADT-doped poly(methyl methacrylate) (PMMA) thin film with a mass fraction of 1% was prepared by spin-coating. The third-order nonlinear optical properties of BTEAADT in acetonitrile and a BTEAADT-doped PMMA film were investigated using the laser Z-scan technique with 20 ps pulses at 1064 nm. The linear optical properties of the polymer thin film were also studied. The Z-scan spectra revealed that the polymer thin film sample possessed negative nonlinear refraction and exhibited a similar self-defocusing effect to that found for the solution. In addition, nonlinear absorption was negligible for both systems under the experimental conditions used. The nonlinear refractive index was calculated to be -1.459×10^-18 m²·W^-1 for the solution sample and -3.978×10^-15 m²·W^-1 for the film. These results suggest that this material is a promising candidate for application in nonlinear optical devices such as all-optical switching manufacture at 1064 nm.

Water-soluble surface modified silver nanoparticles were synthesized by liquid phase reduction with tannic acid as the reductant and polyvinyl pyrrolidone (PVP) as the surface modification agent. The structure and morphology of the as-synthesized powders were investigated by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis) absorption spectroscopy, and Fourier-transform infrared (FTIR) spectrometry. The antibacterial activity of the water- soluble Ag nanoparticles against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was investigated by broth dilution. The stable dispersion duration of the as-synthesized Ag nanoparticles in water was also determined. A mechanism for PVP modified Ag nanoparticle formation is proposed. The results show that the as-synthesized PVP modified Ag nanoparticles have a face-centered cubic crystalline structure. The average diameter of the Ag nanoparticles ranges from 15 to 17 nm. The as- synthesized powders have od solubility in water over a long period of time. PVP modified Ag nanoparticles exhibit od antibacterial properties against E. coli and S. aureus. This simple and mild preparation method can be easily increased to an industrial scale process and, therefore, PVP modified Ag nanoparticles are potentially a new type of antibacterial.

Mesoporous carbon materials with a range of pore sizes were synthesized by a delicately controlled procedure using disordered γ-alumina as template and sucrose as carbon source. Under optimized conditions, the carbon materials had narrow pore size distribution, large surface area (>1000 m²·g^-1), large pore volume (up to 3.82 cm³·g^-1), high mesopore ratio (>99%), and thin pore walls with thickness of 1-2 graphene layers. In the present work, we employed three types of alumina, and investigated the correlation of their texture with that of the resultant carbon materials. A mechanism for the formation of the carbon materials was proposed and tested against experimental data. A carbon sample prepared by this method can approximately duplicate the pore structure of the template, if the carbon layer in the precursor carbon-covered alumina is complete and sufficiently robust. The mesopores of the carbons had two sources, one from the removal of the template particles and the other from the original pores of the template. Calculated pore volumes strongly support the proposed mechanism.

A stable hydrosol of graphene was synthesized by oxidation reduction and then a flow assembly of this graphene was used to form a graphene-based membrane by vacuum extraction filtering method. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, particle size analysis, and scanning probe microscopy (SPM) were used to characterize the crystal structure, granularity, and characteristic change of the molecular spectrum of the samples in the reaction. FTIR tests show that the structural layer of graphite during the oxidation process bonds to a large number of functional groups and parts of these stable functional groups remain on the reduced structural layer of graphene. X-ray diffraction results show that the peaks of the graphite oxide shift to lower angles, become broader and the original graphite peak disappears. Suspensions of graphene oxide form condensed matter and graphene flocculating constituent during film deposition. Particle size analysis and SPM tests show that the particle sizes of the graphene oxide sheets that are dispersed in water show a tailing peak and a broad distribution while the graphene sheets show a singlet, narrower distribution, and smaller dimensions. Raman results show that during oxidation and reduction, the D peak and G peak of the samples gradually extend, I_D/I_G increases gradually and the degree of sample disorder increases. On the basis of the above analyses, the structural characteristics of the samples in the reaction are summarized.

We synthesized mesoporous MnO₂ nanospindles by a one-step hydrothermal process in an aqueous solution of KMnO₄ and glucose. The structure, morphology, purity, and size of the products were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), and nitrogen adsorption/desorption (BET) measurements. The reaction time and concentrations of glucose influenced the final structures and shapes of the MnO₂ nanospindles. The length to diameter ratio of the MnCO₃ precursor nanospindles can be easily tuned from 1.35:1 to 2.89:1. A possible formation mechanism for the mesoporous MnO₂ nanospindles is proposed and discussed.

An anodic aluminum oxide (AAO) ultrathin film (~140 nm, about half the thickness of the original Al film) was successfully fabricated directly onto an indium tin oxide (ITO) electrode without the erosion of ITO by a two-step anodization process in 0.3 mol·L^-1 O₂SO₄ solution at a constant voltage of 20 V. Here, a thin titanium buffer layer was included between the ITO electrode and the Al film by radio frequency (RF) magnetron sputtering. A large area (about 4 cm²) of porous alumina with nanoscaled channels perpendicular to the substrates was obtained. The average pore diameter and the pore interspace were approximately 30 and 60 nm, respectively. We found that the Ti buffer layer with a thickness of 10-40 nm between the Al layer and the ITO substrate played a critical role in improving the adhesion and ensuring ITO protection, which could not be duplicated by other metals, e.g., Cr, Au, Ag, and Cu. UV-visible transmittance spectra confirmed that the Ti buffer layer was oxidized and became transparent TiO₂ and that 10-20 nm of the Ti buffer layer together with the two-step anodization process is suitable for high transparency. Therefore, the AAO specimen possessing a high nanoscale regularity and transparency may have potential use in photonics, photovoltaics, and nanofabrications.

We successfully prepared a novel inorganic-organic hybrid electrostatically self-assembled multilayer film by alternately depositing Prussian blue (PB) and a thiophene-containing hemicyanine. The optical, electrochemical, and photoelectrochemical properties of the as-prepared films were studied by UV-visible absorption spectroscopy, cyclic voltammetry, and photoelectrochemical experiment. Linear increases in the absorbances at 376 and 698 nm with the number of deposited layers, up to at least 8 layers, indicated that film deposition was uniform and reproducible. The PB in the prepared films was found to occur surface-confined rather than diffusion-controlled redox reactions and the peak currents increased with an increase in the number of layers up to 5 layers. Upon irradiation with 100 mW·cm^-2 white light the films exhibited stable and reproducible cathodic photocurrents, which increased as the number of layers increased up to 4 layers. A maximum photocurrent density of 0.28 μA·cm^-2 was found for the four-layer film at a bias voltage of -0.4 V vs the saturated calomel electrode.