Preparation TiO₂ Nanotube Arrays By Pulse Anodization And Study On The Properties Of Photoelectricity

The scientists have devotd themselves to work at photocatalytic decomposition of water to hydrogen energy with various semiconductor to produce stored and clean hydrogen chemical energy, since Honda and Fujishima discovery that water could be decomposed to product hydrogen under the solar illumination with TiO₂ semiconductor, increasingly improved the photocatalytic perfor acesof semiconductor, and got spectacular results.With the development of science and technology. The living standards of penple are improving every day. The growing demand for energy throughout the world has caused great importance to be at tached to the exploration of new. Solar and hydrogen energy are considered as the'Green Energy'which is most likely to gradually replace foss fuels,in the past several decades. TiO₂-based nanostructure semiconductors have been extensively studied due to their excellent chemical stability, nontoxicity, low-cost and high photocatalytic activities. It is can save a lot of prmeparation time and enhance preparation efficiency. By reason of impulse power supply can promote voltage of max. after that then, split second resume zero pressure. split second reverse voltage promote max, then, reverse voltage become zero. This can avoid lot of time that formation TiO₂ nanotubes.In this experiment, we adopt bidirectional pulse power source. Before pulse anodization, the Ti foil is prepared from high-purity 99.99% cut the foil with 12cm2 area and 0.4mm thickness. Then it was mechanically polished, using SiC paper of successively finer roughness (1000 and 2000 grit). Surfaces showed a homogenous distribution of TiO₂ nanotubes by mirror finished. This contrasted with the preferential growth along grooves occurring when the Ti surfaces were left with microscopic grooves resulting from a (rougher) sand paper polish treatment . After polishing proc, the Ti foils were cleaned in three 15 min steps in ultrasonicated acetone, alcohol, and finally ultrapure water before drying in flowing N2 stream; the sample was applicationed immediately after cleaning. After that, along with impulse power supply hoist pressure 1V, 2V, 3V, 7V, 12V, 15V. We can see Ti that in electrolyte dissolution in electric field effect gradually enhance. Along with pulse power source hoist 15V. TiO₂-based Nanotude Arrays with the average tube diameter of about 80nm and the tube length about 800nm. Apparently together with direct current power supply 20V preparation showpiece resemble. We can see use pulse power source preparation TiO₂ nanotubes, it is can energy conservation, at the same time it can be enhanced efficiency of photoelectricconversion.We can research photoabsorption through that the ultraviolet light. It is can see that the the ultraviolet light photoabsorption move turn towards the red light. This means that photoabsorption move turn towards visible light, along with the raise voltage.By reason of the duty cycle decisive ratio that the time of output voltage and the minor cycle, that is say the duty cycle decisive persistent period that positive voltage in positive change time. So that the influence of the duty cycle is not ignore. Now that we research law that impulse electrical source preparation TiO₂ Nanotubes in different t duty cycle. Similarly, the time of electrolysis set as an hour. In sight of the duty cycle descend that the pipe diameter of TiO₂ Nanotubes is minify. This is so that the duty cycle is ratio that the hight voltage and the low voltage. The duty cycle set knock-down, the durative time of the hight voltage is abate.A pulse waveform for the anodic growth of TiO₂ nanotubes arrays with Fe-doping is described, because of Fe-doping introduced effective reduced energy gap of TiO₂ (with the narrowing of the band gap), thus making the band width of TiO₂ optical absorption boundary red shift, this experiment confirmed that Fe-doping may enhance light absorption activity of TiO₂ and enhanced efficiency of photoelectricconversion.