In the past two decades, noble metal nanoparticles have been the focus of intensive research due to their unique properties. Researchers have made many efforts to synthesize noble metals with sizes in the nanometer scale and investigated their size- and shape-dependent properties. In this article, we firstly give a brief review on recent synthesis of noble metal particles. Then we mainly discuss their growth mechanism and the relationship between the shape and optical properties. Finally, we highlight a number of potential applications of noble metal materials in some fields.

In view of the scientific issues lying behind (1) the p-type dye-sensitized solar cells (DSCs) (the limited dye loading on the NiO film and serious charge recombination between the reduced dyes and the holes generated in the NiO) and (2) pn-type DSCs (mismatching of photoanode and photocathode), we review the recent progress of the electrodes, dyes, and electrolytes for these types of solar cells. The feasible solution of these issues is discussed and, at last, the future development of these types of solar cells is prospected.

We mainly investigated the phase behavior of the AOT (sodium bis-(2-ethylhexyl) sulfosuccinate/CO₂/ethanol/water quaternary system and the AOT/CO₂/ethanol/1,3-propanediol (1,3-PDO)/water quinary system at 30-50 °C and at pressures of 6.9-10.3 MPa. AOT was used as the surfactant and ethanol was used as the cosolvent at 1,3-PDO concentrations of 2.5%, 5.0%, and 7.5%(w). This result shows that a thermodynamically stable microemulsion can be formed by controlling the operating pressures and temperatures. Subsequently, the selective extraction of 1,3-PDO from the aqueous solution can be controlled using appropriate temperatures and pressures, which is useful for the practical application of this technique in industry.

We studied the reformation processes for structure I (sI) (methane, carbon dioxide) and structure II (sII) (propane) gas hydrates experimentally and investigated the memory effects between sI and sII hydrates using a constant-volume system. During these experiments, the induction period for hydrate formation was observed. Moreover, we also found that there were obvious memory effects in secondary formation of sI gas hydrates as well as in alternate secondary formation of sI and sII gas hydrates.

The Gibbs free energy of a vacuum silicothermic reduction for the production of metallic zinc was calculated and analyzed thermodynamically. The results show that reducing ZnO by silicon is thermodynamically possible at 1100-1500 K. However, about 50%(w) of the ZnO was not reduced because the SiO₂ generated by the reduction of ZnO with silicon can react with ZnO and produce 2ZnO·SiO₂. Upon the addition of CaO, it can react with SiO₂ before ZnO to inhibit the production of 2ZnO·SiO₂ and ZnO can be reduced to Zn completely. Slagging reactions and the vacuum technique can be used to lower the Gibbs free energy of the reduction reaction. We carried out experiments to reduce ZnO from hot dip galvanizing ash using silicon. The results showed that the reduction efficiency of ZnO was 92.81% and the metal Zn obtained was well crystallized under the following experimental conditions: a temperature of 1448 K, a vacuum reduction time of 120 min, and a residual gas pressure of 20 Pa. X-ray diffraction (XRD)analysis indicated that the main compound in the slag was 2CaO·SiO₂.

We synthesized crystalline bis(n-nonylammonium) tetrachlorozincate (C₉H₁₉NH₃)₂ZnCl₄(s) (C₉Zn(s)). X-ray single crystal diffraction, chemical analysis, and elemental analysis were used to determine the crystal structure and composition of the complex. The lattice potential energy U_POT was calculated to be 952.94 kJ·mol^-1 from crystallographic data. The molar enthalpies of C₉Zn(s) dissolution using various molalities were measured in double-distilled water by an isoperibol solution-reaction calorimeter at 298.15 K. According to Pitzer's electrolyte solution theory the molar enthalpy of dissolution of C₉Zn(s) at infinite dilution (Δ_sΗ_m^∞ )] was calculated to be 20.09 kJ·mol^-1 and the sums of Pitzer's parameters (4β_C9H19NH3,Cl^(0)L+2β_Zn,Cl^(0)L+θ_C9H19NH3,Zn^L) and (2β_C9H19NH3,Cl^(1)L+β_Zn,Cl^(1)L) were obtained.

A precursor NH₄CoPO₄ containing Li⁺ was synthesized using a low temperature solid-state reaction with ammonium dihydrogen phosphate, cobalt acetate, and lithium hydroxide. LiCoPO₄ powder was manufactured by high temperature baking. The products were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and thermogravimetry-differential thermal analysis (TG-DTA). The results showed that the formation of the intermediates was effected by the baking atmosphere. NH₄CoPO₄ containing Li⁺ was dehydrated and deaminated in air at 210?500 °C and then the (CoHPO₄·LiCoPO₄·Co₂(OH)PO₄·Li₃PO₄) intermediate (acid-base community) was emerged during the reaction process. The intermediate formation reaction mechanism followed the interfacial reaction power-law with an apparent activation energy of 50.0 kJ·mol^-1. The kinetic function was found to be g(x)=(1-α)^-1. The intermediate was dehydrated to form LiCoPO₄ with an average apparent activation energy of 54.2 kJ·mol^-1. The formation of the intermediate was not affected by the process of crystallization or non- crystallization of the materials. High temperatures accelerated the decomposition reaction of the intermediate and then the formation of LiCoPO₄ crystals. A perfect crystal of LiCoPO₄ was obtained by the decomposition of the intermediate at temperatures higher than 550 °C.

A chemically enhanced mechanism of surface-enhanced Raman scattering (SERS) spectroscopy was investigated using density functional theory (DFT). We studied the Raman spectra of the Ag₁₃/MPH and Ag₁₃/MPH/TiO₂ systems under 514.5 nm excitation. We found that the intensities of the non-totally symmetric vibration modes were selectively enhanced after TiO₂ was introduced into the Ag₁₃/MPH system. By analyzing the ground state and excited states of the charge transfer (CT) complex we found that the system gave a photoinduced CT state from Ag to the MPH-TiO₂ complex when the excitation wavelength exceeded the optical absorption threshold (635 nm) of the MPH-TiO₂ complex. The selective enhancement of the b₂ modes in the SERS spectra probably originates from the Herzberg-Teller mechanism through the coupling of the corresponding modes with the CT transition. Our theoretical results support the experimental results and also define the adsorption threshold of the CT complex clearly while providing an intelligible physical explanation for the laser wavelength-dependent SERS phenomenon.

We carried out molecular dynamics simulations using an embedded atom method to investigate the mechanical properties and structure deformation of silver nanowires during anisotropic stretching along the [100], [110], and [111] orientations. The simulation results show that the mechanical properties are different for the three crystal directions. Before breaking, linear atomic chains were observed for all three orientations. A total of 900 samples were investigated for a comprehensive understanding of the influence of orientation on the formation probability of linear atomic chains. Stretching along the [111] direction had a higher probability than that along the other two directions. This difference is explained by a stretching mechanism of the silver nanowire.

The geometrical structures, electronic structures, energetics and vibrational frequencies of bent and linear NFeN molecules with different spin multiplicities were studied at the B3LYP/6-311+G(d) level. We find that: (1) the Fe―N bond length is about 155 pm for singlet states and this is shorter than those in triplets and in quintets; (2) the electronic structures of triplet bent NFeN are more complicated than that of the others. Natural bonding orbital and Mulliken population data indicate that the Fe―N bond displays ionicity; (3) the most stable electronic state among all the states is 1⁵A₂ and the energies of 1³B₁, 1³A₂, 1³B₂, and 11A1 are similar, however, the most stable electronic state of linear NFeN is ³Δ_g. This reaction is endothermic because the energies of all the states are higher than those of the ground state Fe(a⁵D)+N₂(X¹Σ_g⁺) reactants while Fe(a⁵D)+2N(⁴S) is exothermic; (4) according to the calculated structure and vibrational characteristics the 1³B₁ state might be observed in the reported experiments; (5) compared with our previous results the structures of the FeN₂ complexes are very different from that of the NFeN compound; (6) the Fe atom direct insertion reaction into the triple bonds of N₂ is especially difficult because of the energy barriers in the reaction potential energy curves.

A theoretical study of the Li+HF (ν=0, j=0)→LiF+H reaction was carried out using the quasi- classical trajectory (QCT) method based on the latest APW potential energy surface (PES) obtained by Aguado et al. The reaction cross-section, rotational alignment, and angular distributions of the products were obtained at different collision energies. The results indicate that there are two reaction pathways, i.e., an abstraction pathway and an insertion pathway for this reaction. At a low collision energy the insertion mechanism is dominant whereas at high energy (E>200 meV) the abstraction mechanism is dominant.

We studied C₂H₅OH(H₂O)_n (n=1-9) clusters using density functional theory (DFT) at the B3LYP/6-311++G(2d,2p)//B3LYP/6-311++G(d,p) level. We calculated the properties that characterize the C₂H₅OH (H₂O)_n (n=1-9) clusters and these include optimal structures, structural parameters, hydrogen bonds, binding energies, average hydrogen bond strength, natural bond orbital (NBO) charge distributions, and cluster growth rhythm, etc. The results show that the transition from two-dimensional (2-D) cyclic structure to three-dimensional (3-D) cage structure occurs at n=5. Moreover, the lowest energy structure of the C₂H₅OH(H₂O)_n (n=6) cluster is probably a magic number structure as determined by the properties of the second order difference of the binding energy, the formation energy, and the energy gap. Finally, to probe the nature of the hydrogen bond, the properties of the lowest energy structures for the C₂H₅OH(H₂O)_n (n=2-9) clusters were compared with those of pure water clusters (H₂O)_n (n=3-10), and our results show that the hydrogen bonds that form between water molecules in the former are similar to those in the latter.

Hydrogen bonding structure and kinetics in aqueous glucose solutions with different concentrations were studied using the molecular dynamics simulation method. The percentage distributions of glucose and water molecules with i hydrogen bonds (intra, inter, or both) were analyzed. We find that a critical number N exists and the percentage of glucose or water molecules with N hydrogen bonds is the highest. When i<N, the percentage of glucose or water molecules with i hydrogen bonds increases as the glucose concentration increases, while when i>N the percentage of glucose or water molecules with i hydrogen bonds decreases as the glucose concentration increases. Continuous and intermittent autocorrelation functions for the different hydrogen bonds (intra-hydrogen bonds in the glucose molecules, hydrogen bonds between glucose molecules, hydrogen bonds between the water molecules, hydrogen bonds between the glucose and water molecules, and all hydrogen bonds) and the hydrogen bond lifetimes were also calculated.

Molecular dynamics (MD) simulations were performed to investigate the well-known energetic material cyclotrimethylene trinitramine (RDX) crystal, 3,3′-bis-azidomethyl-oxetane (BAMO) and the RDX/BAMO propellant. The results show that the binding energies of RDX with BAMO on different crystalline surfaces change as follows: (010)>(100)>(001). The interactions between RDX and BAMO were analyzed by pair correlation functions g(r). The mechanical properties of the RDX/BAMO propellant, such as the elastic coefficients, modulus, Cauchy pressure, and Poisson's ratio, were obtained. We find that the mechanical properties are effectively improved by adding some BAMO polymer and the overall effect of BAMO on the three crystalline surfaces of RDX changes as follows: (100)>(001)>(010). The energetic performance of the RDX/BAMO propellant was also calculated and the results show that compared with the pure RDX crystal, the standard theoretical specific impulse (I_sp) of the RDX/BAMO propellant decreases but it is still superior to that of the double base propellant.

The reaction mechanisms for the preparation of propylene carbonate (PC) from propylene oxide (PO) and CO₂ in the absence of a catalyst or by catalysis using KI or KI/NH₃ were studied in detail using density functional theory (DFT) at the B3LYP/6-311++G^** level (I atom using the MIDIX basis set). The geometric configurations of the reactants, intermediates, transition states, and products were optimized. Vibration analysis and the intrinsic reaction coordinate (IRC) of the reactions proved that the intermediates and transition states predicted were present. The natural bond orbital (NBO) and atoms in molecules (AIM) theories were used to determine the orbital interactions and the bond nature at the same level. The results reveal that PO+CO₂→M0a→TS0c→M0c→TS0c′→PC is the main reaction channel in the absence of the catalyst and it has a high energy barrier of 200.65 kJ·mol^-1. The energy barrier is reduced to 187.40 kJ·mol^-1 in the presence of KI, and it has a slow reaction rate. However, the energy barrier is reduced to 154.64 kJ·mol^-1 and the reaction rate increases considerably upon promotion by KI/NH₃, possibly because of the formation of hydrogen bonds between H in NH₃ and O in CO₂ or PO, which is in od agreement with the experimental results.

We studied the reaction mechanisms of ethylene dimerization to 1-butene on Ga/HZSM-5 and Al/HZSM-5 zeolite catalysts by theoretical calculations and investigated the influence of zeolite acidity on the reaction energetics. The calculations were performed using the hybrid ONIOM2 (B3LYP/6-31G(d, p):UFF) method based on the two-layered 76T cluster model. Ethylene dimerization may proceed along two different pathways: either a stepwise or a concerted mechanism, and both produce a surface butoxide intermediate. Our results indicated that with respect to the reactions on Al/HZSM-5, the adsorption energy of ethylene on Ga/HZSM-5 was 20.62 kJ·mol^-1 lower, and the activation energy for the protonation process was only 1.26 kJ·mol^-1 higher. Additionally, the activation energy for a combination of ethoxide intermediate with ethylene was 62.55 kJ·mol^-1 higher because of the larger atomic radius of Ga, which led to an unstable six-member ring transition state. For the concerted mechanism, protonation and C―C bond formation proceeded in one step and the activation energy on Ga/HZSM-5 was 16.44 kJ·mol^-1 higher than that on Al/HZSM-5. Therefore, the ethylene dimerization reaction proceeded according to the concerted mechanism. The surface butoxide intermediate was transformed to 1-butene by deprotonation and adsorbed on the recovered Brönsted acid sites. The corresponding activation energy on Ga/HZSM-5 was similar to that on Al/HZSM-5 but it was obviously higher than that in the other steps. Therefore, it was the rate-determining step for this reaction.

The adsorption of 1,3-butadiene, 1-butylene, and n-butane in FAU, BEA, and LTL zeolites was investigated by Monte Carlo (MC) simulations. The adsorption isotherms, distribution of adsorbates, and isosteric heat of the C4 hydrocarbons in the zeolites at 298 K were obtained by simulation. The results show that the amount of C4 hydrocarbon saturated adsorption in FAU was the highest, in BEA it was the second highest, and in LTL it was the lowest. For the same zeolite, the isosteric heat of n-butane was the largest, 1-butylene the second largest, and 1,3-butadiene was the lowest. For the same C4 hydrocarbon, the isosteric heat in LTL was almost the same as that in BEA. The isosteric heat in FAU was the lowest. The adsorption of C4 hydrocarbon mixtures onto the zeolites at 543 K, 2.0 MPa was also simulated. In these mixtures the amount of n-butane adsorption was the highest, 1-butylene the second highest, and 1,3-butadiene the lowest.

Non-structural proteins 5B (NS5B) play an important role in protein maturation and gene replication as an RNA dependent RNA polymerase in the hepatitis C virus (HCV). Inhibiting NS5B polymerase will prevent RNA replication and, therefore, it is significant for the treatment of HCV. It is becoming increasingly important to screen and predict molecules that have NS5B inhibitory activity by computational methods. This work explores several machine learning (ML) methods (support vector machine (SVM), k-nearest neighbor (k-NN), and C4.5 decision tree (C4.5 DT)) for the prediction of NS5B inhibitors (NS5BIs). This prediction system was tested using 1248 compounds (552 NS5BIs and 696 non- NS5BIs), which are significantly more diverse in chemical structure than those used in other studies. A feature selection method was used to improve the prediction accuracy and the selection of molecular descriptors responsible for distinguishing between NS5BIs and non-NS5BIs. The prediction accuracies were 81.4%-91.7% for the NS5BIs, 78.2%-87.2% for the non-NS5BIs, and 84.1%-85.0% overall based on the three kinds of machine learning methods. SVM gave the best accuracy of 91.7% for the NS5BIs, C4.5 gave the best accuracy of 87.2% for the non-NS5BIs, and k-NN gave the best overall accuracy of 85.0% for all the compounds. This work suggests that machine learning methods can facilitate the prediction of the NS5BIs potential for unknown sets of compounds and to determine the molecular descriptors associated with NS5BIs.

A Ni-Mo/LaNi₅ porous composite electrode was successfully prepared by composite electrodeposition and dissolution with a concentrated alkali solution. We found that the electrode consisted of two phases and a porous structure using scanning electron microscopy (SEM) and X-ray diffraction (XRD). In a 20% (w) NaOH solution the electrocatalytic properties toward hydrogen evolution reaction (HER) of the electrode was evaluated using electrochemical steady-state polarization curve and electrochemical impendence spectroscopy (EIS). As a result, the porous composite electrode had od electrocatalytic activity toward HER. We also found that the control step in the HER was the electrochemical de-absorption of hydrogen. The stability of the porous composite electrode was investigated by cycle voltammetry, discontinuity constant potential electrolysis over a long time, and differential scanning calorimetry (DSC). The results show that the stability of the porous composite electrode is od.

A nano-structured manganese dioxide thin film was electrochemically deposited onto a 2304 duplex stainless steel (DSS) electrode. The structure, surface morphology, and composites of the obtained manganese dioxide were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray energy dispersive spectroscopy (EDS), respectively. The electrochemical characteristics of the manganese dioxide electrodes were investigated by cyclic voltammetry (CV), chronopotentiometry, and electrochemical impedance spectroscopy (EIS). The obtained manganese dioxide was found to be amorphous and the surface was composed of nanorods with lengths between 100 and 200 nm. As the mass of the manganese dioxide increased the capacitance also increased while the specific capacitance decreased. With an increase in the CV scan rate the specific capacitance decreased as well. The highest specific capacitance value of 288.9 F·g^-1 was obtained at a scan rate of 20 mV·s^-1 when the mass of manganese dioxide was 0.09 mg. 500 cycles were carried out at a rate of 100 mV·s^-1 and we found that the specific capacitance remained stable and even increased slightly as the cycles increased.

Ordered mesoporous carbon materials were prepared by doping boric acid using a hard- templating method. The capacitive performance of these carbons was investigated in organic and H₂SO₄ electrolytes. As demonstrated by structure analysis the prepared carbons possessed parallel mesoporous channels. The pore size increased from 3.3 to 5.7 nm and the molar fraction of oxygenated groups on the carbon surface increased from 2.0% to 5.2% with an increase in the amount of boric acid doping from 0 to 50% (molar fraction). In the organic electrolyte, the carbons mainly showed typical electric double layer capacitive performance and no visible pseudo-capacitance was induced. In H₂SO₄ electrolytes, BOMC-5 showed the highest specific mass capacitance of 140.9 F·g^-1 and the specific surface capacitance of the prepared carbons increased with an increase in the oxygenated groups and this carbon showed visible pseudo-capacitance because of the rapid redox reactions of the oxygenated groups. The capacitance retention ratio depends on the surface chemical properties, which determines the wettability of the carbon surface and the electrolytes.

Oleic acid-capped α-Fe₂O₃ nanoparticles were initially prepared as precursors by a simple hydrothermal method. Fe₃O₄/C nanocomposites were synthesized by annealing the precursor at 500 °C for 1 h under an Ar atmosphere. The surface organic groups and core phase structure of the samples were characterized by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD), respectively. Scanning electron microscopy (SEM) was used to observe their morphology. The existence of carbon was confirmed by elemental analysis, energy-dispersive X-ray (EDX) spectroscopy and high-resolution transmission electron microscopy (HRTEM). Cyclic voltammetry (CV) and galvanostatic discharge/charge measurements were used to evaluate the electrochemical performance of the as-prepared Fe₃O₄/C nanocomposites. The results showed that Fe₃O₄/C nanocomposites were spindles alike with a length of about 200 nm and a diameter of about 100 nm. A carbon layer of 1-2 nm in thickness was coated on the surface of the Fe₃O₄ nanocrystals and the carbon content was 1.956% (mass fraction). As anode materials for lithium-ion batteries, the composite exhibited excellent cycling performance (691.7 mAh·g^-1 after 80 cycles at 0.2C (1C=928 mA·g^-1)) and rate capability (520 mAh·g^-1 after 20 cycles at 2C). Compared with commercial Fe₃O₄ particles, the remarkably improved electrochemical performance of the Fe₃O₄/C composites was attributed to in situ carbon coating, which prevented nanoparticle aggregation, increased electronic conductivity and stabilized the solid electrolyte interface (SEI) films.

Using the Scharifker and Hills model and Heerman and Tarallo model, cyclic voltammetry and chronoamperometry were used to study the nucleation mechanism upon the electrodeposition of a Pd-Ni alloy from an electrolyte. The results show that the electrodeposition of the Pd-Ni alloy onto glassy carbon electrode consisted of nucleation and growth, and the nucleation process according to the Scharifker and Hills model follows three dimension-progressive nucleation, which is controlled by the diffusion of the electroactive species. By applying the Heerman and Tarallo model, the kinetic parameters associated with the crystal nucleation and growth processes were obtained. The nucleation rate constant and the density of active nucleation sites increased from 0.83 to 7.71 s^-1 and from 2.77×10⁴ to 7.09×10⁴ cm^-2, respectively, as the step potential was changed from -0.85 to -0.92 V (vs SCE).

Novel molecularly imprinted polymers (MIPs) were synthesized by the electrochemical polymerization of o-phenylenediamine (o-PD) using cyclic voltammetry in the presence of Cu(II)- ethylenediaminetetraacetate chelate (Cu(II)-EDTA), which acted as a template. The resultant polymers were characterized by UV-Vis spectroscopy, X-ray photoelectron spectroscopy (XPS), differential pulse voltammetry (DPV), and quartz crystal microbalance (QCM). UV-Vis spectral analysis indicated that a higher degree poly-o-phenylenediamine (PoPD) was obtained at pH≥5.0. XPS analysis clearly showed the successful embedding of a Cu(II)-EDTA chelate in the PoPD film and, therefore, hydrogen bonding was a major interaction between the template and the PoPD film. DPV analysis confirmed the successful removal of the template from the PoPD film. The QCM test showed that the Cu(II)-EDTA imprinted PoPD film had od Cu(II)-EDTA chelate sensitivity.

The effects of benzotriazole (BTA) on the corrosion behavior of reinforcing steel in mortar specimens were studied by corrosion potential (E_corr), polarization resistance (R_p), and resistivity of mortar cover (ρ_c). Additionally, the corrosion inhibiting efficiencies of BTA and NaNO₂ (SN) were compared after exposure to 3.5% (w) NaCl solution for 360 d. Three samples with different surface conditions (as-received reinforcing steel, pre-rusted reinforcing steel, and chloride-admixed in mortar) were studied using electrochemical impendence spectroscopy (EIS), cyclic polarization (CP) and cyclic voltammetry (CV). Environmental scanning electron microscopy (ESEM) and energy dispersive spectroscopy (EDS) were employed to obtain the mechanism of the inhibiting efficiency of BTA in cementitious materials. The results show that under all three conditions, BTA strongly reduces the uniform corrosion rates of reinforcing steels in mortar with inhibiting efficiencies better than those of SN. On the other hand, the pitting corrosion resistance of specimen with BTA is slightly lower than that with SN for the as-received and pre-rusted reinforcing steels. However, when chlorides were pre-mixed in mortar, BTA showed better protection against pitting corrosion. In previous investigations, BTA was found to form a complex film on the surface of the reinforcing steel which restrained the depassivation of the passive film by Cl^-. The results of ESEM/EDS indicate that BTA facilitates more Ca-rich C-S-H gel in the mortar matrix, which may refine the microstructure of the reinforcing steel/mortar interface. The compact microstructure delays the transport of Cl^- towards the steel surface, which protects the reinforcing steel effectively. The long-term (360 d) strength of the mortar specimen is not affected obviously when BTA is used in appropriate proportions.

Monolayers may be obtained by an electrostatic force between cationic surfactants and anionic electrolyte deoxyribonucleic acid (DNA) molecules, and a corresponding Langmuir-Blodgett (LB) complex monolayer can be fabricated by compression and deposition of the monolayer at the air/water interface. In this work, the interaction between cationic Gemini surfactants ([C₁₈H₃₇(CH₃)₂N⁺-(CH₂)_s-N⁺(CH₃)₂C₁₈H₃₇]·2Br^-, abbreviated 18-s-18, s=3, 4, 6, 8, 10, 12) and double-strand DNA (dsDNA)/single-strand DNA (ssDNA) was investigated by surface pressure-surface area (π-A) isotherms, atomic force microscope (AFM), and Quartz crystal microbalance (QCM). Moreover, the limiting molecular areas of 18-s-18 on different subphases were compared. We found that the spacer and the subphase greatly influence the properties of the Gemini surfactants at the air/water interface. In addition, we conclude that the adsorption capacity of the Gemini surfactants with DNA is closely related to their interaction modes.

Glycidyl methacrylate (GMA) was grafted onto micron-sized silica gel particles and the grafted particles of PGMA/SiO₂ were obtained. Subsequently, a ring-opening reaction of the epoxy groups on the grafted PGMA was carried out using iminodiacetic acid (IDAA) as a reagent, which resulted in IDAA group bonding and in the preparation of the composite chelating particles IDAA-PGMA/SiO₂. In this work, the adsorption behavior and adsorption thermodynamics of IDAA-PGMA/SiO₂ toward heavy metal ions and rare earth ions were investigated, and the adsorption mechanism was investigated in depth. The experimental results show that the particles IDAA-PGMA/SiO₂ possess strong adsorption action for heavy metal ions and the adsorption capacity of the Pb²⁺ ions reached 0.235 g·g^-1. The adsorption of heavy metal ions on IDAA-PGMA/SiO₂ is exothermic and is driven by enthalpy, leading to a decrease in the adsorption capacity as temperature is raised. The adsorption of rare earth ions on IDAA-PGMA/SiO₂ is driven by entropy. The adsorption ability of IDAA-PGMA/SiO₂ toward heavy ions is much stronger than that toward the rare earth ions.

A new and improved photocatalyst, reduced graphene oxide (R )-modified Bi₂WO₆ (Bi₂WO₆-R ), was synthesized by a two-step hydrothermal process. The effect of R content on photoactivity was investigated and the optimum mass ratio of R to Bi₂WO₆ was determined to be 1%. Based on scanning electron microscopic study, R does not change the structure and morphology of the Bi₂WO₆ photocatalyst. Therefore, the improvement in the photoactivity of the Bi₂WO₆-R composite is undoubtedly ascribed to R . The presence of graphene can facilitate the dissociation of photogenerated excitons, which leads to more O₂^·- to degrade dye pollutants like rhodamine-B (RhB). Moreover, the efficient adsorption of RhB molecules on graphene is another reason for the improved photoactivity.

TiO₂ and SiO₂-doped TiO₂ (TiO₂/SiO₂) catalysts were prepared using aqueous solutions containing a TiOSO₄ and/or SiO₂ sol in which NH₃·H₂O was used to adjust the pH value by a precipitation method. The as-synthesized photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), N₂ adsorption (BET), UV-Vis diffuse reflectance spectroscopy, NH₃ temperature programmed desorption (NH₃-TPD), and Fourier transform infrared (FT-IR) spectroscopy. The XRD patterns showed that anatase and rutile coexisted in the as-prepared TiO₂ and the rutile phase content increased with the increase in pH value. However, only anatase-TiO₂ was observed in the TiO₂/SiO₂ catalysts. SEM revealed that the surface morphology of the particles was a sub-spherical shape and some agglomeration occurred on the surface while the particle size was mostly between 10 and 25 nm. Surface area measurements showed that the surface areas of the catalysts increased slightly with the increase in pH value. The incorporation of SiO₂ increased the surface area. NH₃-TPD analysis indicated that the amount of surface acid increased as the pH increased. The amount of surface acid on SiO₂-doped TiO₂ was higher than that on TiO₂ when they were prepared at identical pH values. The addition of silica and the high pH value environment led to more surface hydroxyl groups on the catalysts as determined by FT-IR spectroscopy. The photocatalytic activity of the catalysts improved remarkably with the increase in pH value. The photocatalytic activity of SiO₂-doped TiO₂ is better than that of TiO₂. The TiO₂/SiO₂ catalyst has better durability.

Na-promoted CuCoMn catalysts were successfully applied to the highly efficient production of higher alcohols from bio-syngas, which was derived from biomass gasification. The influence of Na content and synthesis conditions (temperature, pressure, and gas hourly space velocity (GHSV)) on higher alcohol synthesis was investigated. The CuCoMnNa_0.1 catalyst gave the best performance for higher alcohol synthesis. Carbon conversion increased significantly with an increase in temperature at lower than 300 °C but alcohol selectivity showed an opposite trend. A higher pressure was found to be beneficial for higher alcohol synthesis. Increasing the GHSV reduced carbon conversion but increased the yield of higher alcohols. The maximum higher alcohol yield that was derived from bio-syngas was 304.6 g·kg^-1·h^-1 with the C₂₊ alcohols (C₂-C₆ higher alcohols) of 64.4% (w, mass fraction) under the conditions used. The distributions of the alcohols and the hydrocarbons were consistent with Anderson-Schulz-Flory (ASF) plots. Adding Na to the CuCoMn catalysts led to an increase in the selectivity toward the higher alcohols and promoted the dispersion of the active elements, copper and cobalt. X-ray photoelectron spectroscopy (XPS) results suggested that Cu was present as a mixture of Cu⁺ and Cu⁰ on the catalyst′s surface after use and Co was present as a mixture of Co²⁺/Co³⁺ and Co⁰. With an increase in sodium addition the Cu⁰/Cu⁺ ratio and the Co⁰ intensity both decreased.

A series of P/HZSM-5 zeolites modified with different metals (Cr, Co, Cu, Zn) were prepared by impregnation. The physicochemical features of the M-P/HZSM-5 catalysts were characterized by X-ray diffraction (XRD), BET surface area measurements, and temperature programmed desorption of ammonia (NH₃-TPD). We investigated the catalytic activity upon the aromatization of ethanol. The results showed that the framework of the modified zeolites was retained while the specific surface area decreased and the distribution of the acid sites changed greatly. Cu-P/HZSM-5 gave excellent catalytic activity. When the P loading and the Cu loading were 3% and 5% on the HZSM-5 zeolites, respectively, P was modified first and then Cu, the aromatization of ethanol over the 5%Cu-3%P/HZSM-5 zeolite achieved 57.6% with a total light aromatic hydrocarbons (BTX) yield at 400 °C and a weight hourly space velocity (WHSV) of 1.0 h^-1.

Titanium dioxide coated multiwalled carbon nanotubes (MWCNTs) composite photocatalysts were prepared by the controllable oxidation of titanium carbide coated MWCNTs obtained by the molten salt method using MWCNTs as a reaction template and metal titanium powder as a titanium source. The effects of the molten salt reaction temperature, the molar ratio of MWCNTs to titanium powder, and the oxidation temperature on the structure and morphology of the products were investigated. The samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The photodegra- dation of a methylene blue (MB) solution was used to evaluate the photocatalytic activity of the catalyst under visible light irradiation (λ>420 nm). The results suggest that the TiO₂ coated MWCNTs keep the similar fibred morphology with the pristine MWCNTs. Uniform and fine well-dispersed TiO₂ coatings on the surface of MWCNTs closely contact with the MWCNTs support and Ti－O－C chemical bonds form between them. The prepared TiO₂/MWCNTs photocatalyst shows higher visible light photocatalytic activity because the MWCNTs increase the adsorption of methylene blue on the photocatalyst and an impurity state is formed close to the valence band of titanium dioxide, which can enhance the absorption and utilization of solar energy.

A series of fluorene-triphenylamine derivatives containing an electron donor-acceptor (D-A) structure based on 9,9-diarylfluorene was designed and synthesized. Their optical properties were investigated by UV-Vis spectroscopy and photoluminescence (PL) techniques in solution as well as in the solid state. The maximum PL emission wavelengths of the compounds ranged from 430 to 530 nm. A dual fluorescence phenomenon was observed in particular polar solvents and the relationship between emission properties and molecular structures was studied. The results reveal the existence of a charge transfer (CT) excited state in the molecules and the PL properties of these compounds depend on the structure of the compound and also on the polarity of the solvent. The molecular constitution of the compounds improves the hole-injection issues for fluorene-based materials because of the introduction of a triphenylamine group. Cyclic voltammetry (CV) shows that the highest occupied molecular orbital (HOMO) energy level of the compounds is located between -5.24 and -5.50 eV and it can be tailored by changing the electronegativity of the substituent group. Simultaneously, the spiro-skeleton molecular structure leads to an excellent glass transition temperature (192-206 °C) and it retains od morphological stability. The thermogravimetric (TG) curves of the compounds show a thermal-decomposition temperature of higher than 400 °C.

Microcalorimetry was used to study the influence of extracellular NaCl concentration on the growth metabolism of Halobacterium halobium (Hbt. halobium) using a TAM air isothermal microcalorimeter. The metabolic thermogenic curves of Hbt. halobium growth in different concentrations of NaCl were obtained using the ampoule method. The thermokinetic equations and parameters of Hbt. halobium growth were calculated and the relationship between each thermokinetic parameter and the concentration of NaCl was obtained. The results showed that the optimum NaCl concentration for Hbt. halobium growth was not a wide range from 3.5 mol L^-1 to about 5.2 mol·L^-1 (NaCl saturation), as is generally acknowledged, but just around 3.9 mol·L^-1. For an extracellular NaCl concentration above 3.9 mol·L^-1, the growth metabolism of Hbt. halobium decreased constantly with an increase in the NaCl concentration. Further investigation by transmission electron microscopy revealed that the Hbt. halobium cells growing in approaching NaCl saturation underwent plasmolysis, which interpreted the finding of microcalorimetry perfectly. All these results led to a new interpretation of the structural transformations of Hbt. halobium upon NaCl concentration altering.

Hydrogenated silicon nitride films were prepared on the p-type polished silicon substrates by the direct plasma enhanced chemical vapor deposition (PECVD). The influences of deposition temperature on the composition, optical characteristics, structural characteristics, and passivation characteristics of the SiN_x:H film were studied. All the solar cell devices were fabricated using industrial state-of-art crystal silicon solar cell technology. The influence of deposition temperature on the as-fabricated cell's electrical performance is demonstrated. The refractive index of the film ranges from 1.926 to 2.231 and it increases with an increase in the deposition temperature. This shows that the Si/N mole ratio also increases with deposition temperature. The Si－H bond and the N－H bond break and form a new Si－N bond when the deposition temperature is higher. This increase in the Si－N concentration results in an increase in film density. The effective minor carrier lifetime of the coated wafer increases initially with the substrate temperature. At a temperature of 450 °C the effective minor carrier lifetime begins to decrease. This phenomenon can be explained by H extraction from the film. For all the samples, the effective minor carrier lifetime degrades with time. The SiN_x:H film prepared at a deposition temperature of 450 °C shows the best anti-reflection and surface passivation properties. The electrical performance of the fully functional solar cells is also demonstrated and the optimized results are highlighted and discussed.

A LiMn(BH₄)₃/2LiCl composite was prepared by reactive ball-milling a mixture of LiBH₄ and MnCl₂, and its dehydrogenation properties were investigated. The results indicate that the LiMn(BH₄)₃/2LiCl composite consists of crystalline LiCl and amorphous LiMn(BH₄)₃, and decomposes at 135-190 °C with an activation energy of 114.0 kJ·mol^-1, resulting in an emission of 7.0% (w) gas. The released gases contain 96.0% H₂ and 4.0% B₂H₆ (mole fraction, x), which is the reason for why the mass loss of the LiMn(BH₄)₃/2LiCl composite is larger than that of theoretical hydrogen capacity of 6.3% (w). Moreover, the influence of various Ti-containing dopants on the decomposition of the LiMn(BH₄)₃/2LiCl composite was studied. We found that among TiF₃, TiC, TiN, and TiO₂, only TiF₃ achieved a reduction in decomposition temperature. Compared with the undoped LiMn(BH₄)₃/2LiCl composite, the onset decomposition temperature and the activation energy of the TiF₃-doped composite are reduced to 125 °C and to 104.0 kJ·mol^-1, respectively. These are attributed to the formation of Ti(BH₄)₃ in some local regions of the TiF₃-doped composite by the partial substitution of Ti for Li in LiMn(BH₄)₃.

Structural engineering of nanocrystals is of great importance to control the properties of semiconductor oxides. Here, we present a mild wet chemical reduction route to obtain a sub-micron porous jujube-like Cu₂O hierarchy structure. Sodium dodecylbenzene sulfonate (SDBS) is crucial in structural regulation and it acts as a soft template and a capping agent. The jujube-like particle consists of crystal grains less than 10 nm in size as verified by transmission electron microscopy (TEM) and X-ray diffraction (XRD). A set of time control experiments were carried out to study the evolution of the jujube-like structure. Interestingly, we found that altering the amount of added HCl resulted in a size-tuning effect of changing the size of the particles from approximately 300 to 900 nm. Based on these results, we propose a possible growth-etching competition mechanism to explain the formation of the hollow interior and its porous nature, which also agrees with the sizing-tuning effect. The optical properties were analyzed using Raman spectroscopy. By comparison with a conventional sub-micron solid polyhedral we found a novel Raman property for the porous jujube-like Cu₂O. Our research complements the library of Cu₂O Raman spectra, which is meaningful for the nondestructive examination of pigments on the surface of antiques by Raman techniques.