Tio <sub> 2 </ Sub> Nanomaterials And Photocatalytic Hydrolysis Of Hydrogen Production Research

Four kinds of TiO2 (titanium dioxide) powder catalysts,pure TiO2,Fe3+(ferric metal ion)-doped TiO2,N(nitrogen non-metallic element)-doped TiO2 and Fe3+/N-codoped TiO2 respectively,were prepared by modified sol-gel method,aiming at filter out the best TiO2 catalyst and determining the optimal process conditions.Single factor experiment and catalyst characterizations were carried out in order to analyze the influences of doping elements,doping contents and other factors during the preparation process on the properties of catalyst,and thus the mechanism of modification by element doping was concluded.Further more,the four kinds of TiO2 powder catalysts were treated by hydrothermal method under different reaction conditions. Single factor experiment and catalyst characterizations were conducted for determining the optimal hydrothermal reaction conditions.Properties of catalysts after treatment improved a lot compared with that not been treated.TiO2 catalysts after treatment were characterized to analyze their structures and properties by means of XRD,BET,SEM,TG/DSC and UV-Vis, including crystal structure,absorbance of visible light,ratio of surface area,particle size and thermal stability. characterization results showed that the particle size was reduced, the specific surface area was increased,the absorption range of visible light was widen and the photocatalytic activity was greatly improved after TiO2 was modified by doping with Fe3+ or N,especially co-doping with Fe3+ and N.Properties of TiO2 catalysts was significantly improved after treatment,especially in specific surface area and absorption range of visible lightPhotocatalytic water splitting reaction was carried out to research photocatalytic activities of all kinds of doped TiO2 catalysts,which were represented by yield of hydrogen,the splitting product of water.The photocatalytic activity in a descending order was that Fe-N/TiO2>Fe/TiO2>N/TiO2>TiO2 respectively and the best hydrogen yield was about 31.20 umol·h-1·g-1 cat while Fe-N/TiO2 was used.Based on single-factor test results related to yield of hydrogen,the optimal preparation conditions were determined,including calcination temperature,reaction time,hydrothermal reaction temperature,hydrothermal reaction time and the doping ratio.Response Surface Methodology(RSM) was adopted to optimize the process conditions and predict the best yield of hydrogen.