Synthesis of Cuox/Tio2 Photocatalysts with Enhanced Photocatalytic Performance

Abstract

CuOx/TiO2 co-photocatalysts with various Cu loading contents were synthesized by impregnation method and their photocatalytic activities were evaluated by photodegradation of organic pollutants under visible light illumination. The as prepared CuOx/TiO2 composites exhibited a unique structure, in which CuOx clusters with about 2~3 nm nanocrystals were uniformly distributed on the TiO2 cube. The mesoporous Ti3+/TiO2 substrate with uniform pore structure greatly improved uniformity of the loaded Cu, wherein Ti3+ acted as a reducing agent for reducing Cu2+ to Cu+ and Cu0. The reversible process of Cu species between Cu+ and Cu0 markedly enhanced the photocatalytic activity of the CuOx/TiO2 co-photocatalyst, by promoting the transfer of photogenerated electrons and suppressing the recombination of photogenerated electron and hole pairs. The synergistic effect between CuOx and TiO2 also played an important role for enhancing photocatalytic activity of CuOx/TiO2 co-photocatalyst. Results indicated that CuOx/TiO2-1.0 had the highest photocatalytic efficiency, which was 1.5 times higher than that of commercial nano TiO2 P25 under visible light, and demonstrated a good stability even after five recycles. This structural design and the valence control strategy for Cu atom provide an idea that facilitates the utilization of visible light and the improvement of photocatalytic activity of TiO2, promoting the practical application of TiO2 photocatalyst.

Keywords: CuOx/TiO2, photocatalysis, visible-light, synergistic effect