Synthesis, structure and photocatalytic activity of nano TiO_2 and nano Ti_(1-x)M_xO_(2-δ) (M = Cu, Fe, Pt, Pd, V, W, Ce, Zr)

摘要

We have synthesized 5-7 nm size, highly crystalline TiO_2 which absorbs radiation in the visible region of solar spectrum. The material shows higher photocatalytic activity both in UV and visible region of the solar radiation compared to commercial Degussa P25 TiO_2. Transition metal ion substitution for Ti~(4+) creates mid-gap states which act as recombination centers for electron-hole induced by photons thus reducing photocatalytic activity. However, Pt, Pd and Cu ion substituted TiO_2 are excellent CO oxidation and NO reduction catalysts at temperatures less than 100℃.