Abstract
Carbon dioxide is the major contributor to greenhouse effect. Recent year, the concentration of carbon dioxide increased dramatically, and made global warming become more serious. Discussion and application of carbon dioxide fixation technology to reduce its content in the atmosphere is an important topic of global warming mitigation. The use of semiconductor photocatalyst to photoreduce CO2 into methanol or other hydrocarbons. This way can be applied not only to reduce the CO2 emissions, but also convert CO2 into economic organic compounds . In this study, we can fabrication vertical distribution and density of titanium dioxide nanotubes arrays on titanium foil, through the organic electrolyte containing fluoride ions and fixed-voltage DC power. And we doped nitrogen into catalyst by annealed it with urea. Compare to nanoparticles, titanium dioxide nanotubes arrays can promote the separation of electron-hole pair. The immobilized catalyst film is much easy to recycle and be used again. Doping nitrogen can enhance the capacity of absorption of visible light, by this way, we can enhance the efficiency of the use of photocatalysis under solar light. In the study of CO2 reduction, the yield of titanium dioxide nanotubes arrays thin film is much better than nanoparticles thin film. Under simulator solar light, the yield of catalyst which doped nitrogen is better than undoped one, and the one annealed under 500 ℃ show the highest yield.