负载CuO的Ti^(3+)/TiO_2催化剂制备及其光催化甲苯降解性能

Preparation of the Ti^(3+)/TiO_2 supported CuO catalyst and its photocatalytic performance in the degradation of toluene

通过在锐钛矿TiO_2载体表面上负载Cu-BTC(BTC,1,3,5-苯甲酸)前驱体,还原处理制备光催化剂CuO-Ti^(3+)/TiO_2(Cu-TiMB),对其在可见光条件下气相甲苯净化催化性能进行了研究。结果表明,该改良方法制备的CuO-Ti^(3+)/TiO_2(CuTiM B)催化剂的活性是浸渍法所得催化剂CuO-TiO_2(Cu-TiD)的2.68倍。CuO-Ti^(3+)/TiO_2(Cu-TiMB)具有更大的比表面积(147 m2/g)和较小的颗粒粒径(0.45μm),呈现多孔状,CuO的分散度较高;催化剂表面Ti^(3+)提供了大量的氧缺位,在400-800 nm波段的光响应能力显著增强。CuO-Ti^(3+)/TiO_2(Cu-TiMB)催化剂中Cu^(2+)、Cu^+与Ti^(3+)形成的异质结构进一步增多了氧缺位数量,延缓e--h+的复合时间;氧缺陷增强了捕获吸附氧能力,通过金属氧化物价态变化增强化学吸附能力,提高了光催化性能。

The CuO-Ti^3+/TiO 2(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-Ti^3+/TiO2(Cu-TiMB)by visible irradiation was 2.68 time higher than that of CuO-TiO2(Cu-TiD)prepared by impregnation.The CuO-Ti^3+/TiO2(Cu-TiMB)catalyst shows relatively high surface area(147 m^2/g),small particle size(0.45μm),porous structure and high CuO dispersion;Ti^3+may provide a large number of oxygen vacancies,which can significantly enhance the photocatalytic response at 400-800 nm.In addition,Cu^2+and Cu^+may form heterogeneous structure with Ti^3+,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.