Papers by Author: Chun Mei Zhang

Abstract: The TiC/Ti(CN)/TiN multilayer coatings were deposited on 42CrMo steel by chemical vapor deposition (CVD) method. The fracture morphology,structure,microhardness and adhesion of the coatings were analyzed. The immersion test in simulant solution with H2S,CO2 at 100°C and electrochemistry test in 20wt% H2SO4 at room temperture were applied to investigate the corrosion resistance of the multilayer films.The results reveal that the multilayer coatings can offer 42CrMo steel higher corrosion resistance,especially the immersion corrosion test.The corrosion rate of the samples coated with CVD multilayer films is reduced more 70 times than that of the uncoated and samples by quenching-polishing-quenching (QPQ) treat.

Abstract: The preparation and the photocatalytic degradation NO2 - activity of Fe3+-doped TiO2 nano-sized particles is reported in this paper. The TiO2 nano particles were prepared by sol-gel method. The various influence factors about the synthesis process of the Fe3+-doped TiO2 nano photocatalyst were controlled and investigated by XRD (X-ray diffraction), SEM (scanning electron microscopy), and TEM (transmission electron microscopy) etc.. The results show that the phase compositions, crystalline grain size, crystal structure , and photocatalytic activity of the Fe3+-doped TiO2 particles prepared by the method depend on the synthesis technology parameters such as calcination temperature, holding time, Fe3+ ions concentration etc.. The influence factors of the preparation process has been discussed. The photocatalytic decomposition of NO2 - ion into N2 and O2 using Fe3+ and Ce4+-doped TiO2 photocatalysts were investigated under UV irradiation. It was fund that Fe3+-doped TiO2 photocatalysts shows much higher photocatalytic activity than that of the Ce4+-doped TiO2 . The photocatalytic decomposition effect of NO2 - ion is related to the crystalline grain size, irradiation time, and the Fe3+ ions concentration. The Fe3+-doped TiO2 nano powders exhibited the photocatalytic degradation NO2 - activity under UV light irradiation.