Preparation of the Ti³⁺/TiO₂ supported CuO catalyst and its photocatalytic performance in the degradation of toluene

The CuO-Ti³⁺/TiO₂(Cu-TiMB) pholocatalyst was prepared by reducing TiO₂ loaded with Cu-BTC (BTC, 1, 3, 5-benzoic acid) precursor; its photocatalytic performance in the removal of gaseous toluene was investigated. The result indicated that the toluene removal efficiency of CuO-Ti³⁺/TiO₂(Cu-TiMB) by visible irradiation was 2.68 time higher than that of CuO-TiO₂(Cu-TiD) prepared by impregnation. The CuO-Ti³⁺/TiO₂(Cu-TiMB) catalyst shows relatively high surface area (147 m²/g), small particle size (0.45 μm), porous structure and high CuO dispersion; Ti³⁺ may provide a large number of oxygen vacancies, which can significantly enhance the photocatalytic response at 400-800 nm. In addition, Cu²⁺ and Cu⁺ may form heterogeneous structure with Ti³⁺, which can further increase the number of oxygen vacancies and delay the electron-hole pairs (e^--h⁺) recombination time. The oxygen vacancies are effective in enhancing the ability for capturing adsorption oxygen, promoting the chemisorption ability by changing the valence state of metal oxides, and then improving the photocatalytic performance.