Synthesis, structure and photocatalytic activity of nano TiO₂ and nano Ti_1-xM_xO_2-δ (M = Cu, Fe, Pt, Pd, V, W, Ce, Zr)

摘要

We have synthesized 5–7 nm size, highly crystalline TiO₂ 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 TiO₂. Transition metal ion substitution for Ti4+ 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 TiO₂ are excellent CO oxidation and NO reduction catalysts at temperatures less than 100° C.