Papers by Author: Yong Cai Zhang

Abstract: Using BP neural network method, we calculate and analyze the molecular structure of aromatic hydrocarbons. Then, we get the electrotopological state indices and the molecular electronegativity distance vectors of 25 aromatic hydrocarbons based on the calculation of molecular structure characteristics and adjacency matrix. By regression, we get and optimize the structural parameters E₉, E₁₃, E₁₇ and M₁₅. The four structural parameters are used as the input variables and a 4-2-1 network structure is employed to construct a BP artificial neural network model for predicting acute toxicity pEC₅₀. The total correlation coefficient R is 0.994 and the average error between the predicted value and experimental value of pEC₅₀ is 0.079, which indicate that the ANN model has good stability and superior predictive ability. The results show that there is a good nonlinear correlation between acute toxicity pEC₅₀ and the four structural parameters. The results of our research reveal that the toxicity of aromatic hydrocarbons is closely affected by electrotopological state indices and the molecular electronegativity distance vectors. Therefore, it will be helpful in assessing the hazard of aromatic hydrocarbons to environment.

Abstract: A two-step method was developed for the preparation of CdO nanowires from CdO2 nanoparticles, that is, first, Cd(OH)2 nanowires were synthesized via solvothermal treatment of CdO2 nanoparticles in the mixed solution of deionized water and toluene at 180 °C for 24 h; second, CdO nanowires were obtained by thermolysis of the Cd(OH)2 nanowires in air at 300 °C for 3 h. The obtained products were characterized by powder X-ray diffraction and transmission electron microscopy.

Abstract: TiO₂/SnS₂ nanocomposite was synthesized via hydrothermal treatment of tin (IV) chloride pentahydrate, thioacetamide and TiO₂ nanotubes in deionized water at 150 °C for 3 h. The structure, composition and optical property of the as-synthesized nanocomposite were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy and UV-vis diffuse reflectance spectra, and its photocatalytic property was tested in the reduction of aqueous Cr⁶⁺ under visible-light (λ > 420 nm) irradiation. It was observed that TiO₂ nanotubes exhibited no photocatalytic activity, whereas TiO₂/SnS₂ nanocomposite exhibited photocatalytic activity in the reduction of aqueous Cr⁶⁺ under visible-light (λ > 420 nm) irradiation.

Abstract: A low temperature (130 °C) hydrothermal method was proposed for the synthesis of SnO2-SnS2 nanocomposite. The composition, structure and optical property of the as-synthesized SnO2-SnS2 nanocomposite were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy and UV-vis diffuse reflectance spectra, and its photocatalytic activity was tested by the reduction of Cr(VI) in water under visible light (λ > 420 nm) irradiation. It was found that the as-synthesized SnO2-SnS2 nanocomposite exhibited high photocatalytic activity in the reduction of Cr(VI) in water under visible light (λ > 420 nm) irradiation, whereas SnO2 nanoparticles displayed no photocatalytic activity in the reduction of Cr(VI) in water under visible light (λ > 420 nm) irradiation.

Abstract: An in situ thermal oxidation strategy was proposed for synthesizing different SnO2 nanostructures, using our homemade SnS2 nanoplates as a precursor. The characterization results from X-ray diffraction, energy dispersive X-ray spectroscopy, and field emission scanning electron microscope revealed that the heating temperature played an important role in the microstructure and composition of the resultant products. By heating the SnS2 nanoplates in air at 400, 600 and 800 °C for 5 h, nanoplates, a mixture of nanoplates and nanoparticles, and nanoparticles of SnO2 were synthesized, respectively. The residual S was about 2.2 mol % in the product synthesized at 400 °C, while no residual S was detected in the products synthesized at 600 and 800 °C.

Abstract: SnS2/SnO2 nanocomposite was synthesized by a simple in situ hydrothermal oxidation route, and characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy and UV-vis diffuse reflectance spectrum. The as-synthesized SnS2/SnO2 nanocomposite displayed much superior photocatalytic activity to SnS2 and SnO2 nanoparticles in the reduction of aqueous Cr(VI) under visible light (λ > 420 nm) irradiation.

Abstract: A simple and cost-effective method based on the reduction of AgNO₃ by H₂O₂ (5 vol.%) in 2.5–5 vol.% NH₃•H₂O aqueous solutions at room temperature and under atmospheric pressure was developed for the synthesis of Ag submicron crystallites. X-ray diffraction patterns demonstrated that the resultant products were pure cubic phase Ag powders. Field emission scanning electronic microscopy images showed that the Ag powders synthesized in 2.5 and 5 vol.% NH₃•H₂O aqueous solutions comprised submicron crystallites with the sizes of about 355–580 and 200–650 nm, respectively. Besides, the possible formation mechanism of Ag powders in the present system was also proposed.

Abstract: The electrochemical interaction between bacteria and electrode should be further strengthened at the present stage in order to develop microbial fuel cells (MFCs) to practical power sources. Developing effective anode materials is an alternative to achieving this goal. In this study, the redox activity of polyaniline (PAn) in neutral pH solution was improved by doping ionic liquid (IL) into the synthesized PAn; and the current output of MFC could be enhanced by using IL doped polyaniline (PAnIL) film as anode material. Both cyclic voltermmeter (CV) measurement and MFC operation showed that PAnIL electrochemically synthesized in solution with 30%(v/v) IL addition exhibited the best performance.

Abstract: ZnO2 nanorods were synthesized via hydrothermal treatment of 2ZnCO3•3Zn(OH)2 powder in 30 mass% H2O2 aqueous solution at 170 °C for 12 h, and characterized by means of X-ray diffraction, transmission electron microscopy and UV–vis diffuse reflectance spectra. Besides, the photocatalytic activity of the as-synthesized ZnO2 nanorods was tested for the degradation of methyl orange in distilled water under UV light irradiation.

Abstract: ZnO₂ nanoparticles were synthesized via hydrothermal reaction between Zn₅(CO₃)₂(OH)₆ powder and 30 mass% H₂O₂ aqueous solution at 80 °C for 24 h, and ZnO powders with granular and rodlike morphologies were synthesized via hydrothermal decomposition of the as-synthesized ZnO₂ nanoparticles in water at 150-170 °C for 24 h. The obtained products were characterized by X-ray diffraction, Raman and Field emission scanning electron microscopy.