Papers by Author: Hui Zhang

Abstract: Using Y2O3, Mn(CH3COO)2·4H2O as raw materials and glacial acetic acid as solvents, YMnxFe1-xO3 precursors (x= 0, 0.05, 0.1, 0.3, 0.5) have been prepared under 80°C water bath conditions. Perovskite YMnxFe1-xO3 samples were achieved after calcination over 900 °C for 4 h. Structure of the samples was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Ultraviolet obvious diffuse reflection(UV-vis DRS), and Field-emission scanning electron microscopy (FESEM). Photocatalytic activity of the samples was also investigated. Results showed that all the samples with stable perovskite structure had high light absorption in visible-light region, suggesting good visible light harvesting. SEM image showed that the samples were sponge-like and porous agglomerates. Photodecoloration activity of 100 mL Rhodamine B (10 mg/L) was 16~56 % under illumination for 150 min. Oxygen vacancies of the perovskite may explain the high activity of x = 0.1 sample.

Abstract: Copper hydroxyphosphate,as self-assembled nanoparticles, was synthesized by using a hydrothermal method,with cupric acetate (Cu(CH3COO)2·H2O) and diammonium hydrogen phosphate ((NH4)2HPO4) as raw materials. Physical property of copper hydrophosphate was characterized by X-ray diffraction (XRD), Field-emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), and Ultraviolet obvious diffuse reflection(UV-vis DRS). No surfactants or templates were added in the procedure of preparation. By simply adjusting the pH from 3 to 9, the morphology of copper hydrophosphate varied from microrods to walnutshaped microspheres. Photocatalytic activity of the samples was also investigated. Photo decoloration of Rhodamine B in water under visible light irradiation shows that copper hydrophosphate (pH=7) have the best photocatalytic activity: Photodecoloration activity of 100 mL Rhodamine B (10 mg/L) was 98 % under illumination for 30 min.

Abstract: Using nitrate precursors, a novel microwave-assisted progress for the preparation of nanocrystalline pure YFeO3 phase has been developed. Synthesis of perovskite YFeO3 has been achieved with carbon to enhance microwave absorption, polyvinyl alcohol as inhibitor and urea as homogeneous precipitator. The precursor led to formation of phase pure YFeO3 nanocrystalline (52-64 nm) after calcination. The obtained YFeO3 samples were characterized by XRD analysis, N2 adsorption, FT-IR, SEM, TEM, UV-vis/DRS. The synthesis is a fast, simple and inexpensive process and such nanosized YFeO3 has a potential application in photocatalysis under visible light irradiation due to its structure of perovskite-type and photo-absorption property.