Preparation Of Nano - TiO 2 Photocatalyst By Microwave Water And Its Modification

Nowadays, environmental pollution and energy shortage have been increasingly clamping down our sustainable development strategy owing to the over-exploitation. To solve this problem, millions of people and researchers from all fields carried out varieties of work and showed great interests in solar photocatalytic oxidized degradation for its rapid degradation rate, non-second pollution, and abundant energy. Among all semiconductor oxides, TiO2is the most extensively studied and applied material in environmental pollution control owing to the strong oxidization, non-toxic property and outstanding chemical stability.In this thesis, nano-TiO2photocatalytic powder were prepared by microwave-assisted grinding method, and modified by doping iron-ion. The pure and modified TiO2photocatalytic powder were characterized by various teniques. such as therm ogravimetry-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Raman spectroscopy. BET surface. UV-vis absorption spectra and so on. Based on analysis of microwave-assisted grinding process, the influence of roasting temperature, holding time and doping amount on crystal type, grain size, BET surface. UV-vis absorption spectra and catalytic activity were studied by the first time.It was showed that on the process of roasting, Ti(C2O4)2·2H2O would desorbe crystal water around112℃forming Ti(C2O4)2, and at about220℃the Ti(C2O4)2would decompose to TiO2.The photocatalytic activity of pure TiO2photocatalytic powder calcined between400-600℃phase was better and the particles of prepared power were round shap with uniform particulates, and their grain size existed mainly around180nm. The best prepared conditions for iron-doped TiO2photocatalytic powder was calcining at500℃. holding up30min, and doped with0.5%Fe ion. Compared to conventional calcination, the prepared samples roasted by microwave was characterized by high crystallinity, low crystallinity energy, uniformity heating, small particle size and high BET surface, and the absorption edges was also obviously red shift. The initial adsorption and degradation rate of methylene blue was significantly higher than conventional solid-state grinding method.In this paper, TiO2photocatalyt powder were prepared by solid state grinding method assisted by microwave heating technology and modified by Fe ions doping. It showed that microwave heating had advantage in the preparation of functional materials. The influence of roasting temperature, holding time and doping amount on TiO2photocatalytic powder crystallize type, particle size, BET surface, UV-vis absorption spectra and photocatalytic activity were got through systematieally experimental study and various data analysis.