MoO_3-TiO_2复合物的制备及其增强光催化活性

Synthesis of MoO_3-TiO_2 composites and their enhanced visible-light photocatalytic activity

目的通过水热法制备MoO_3-TiO_2复合光催化剂,对其结构和催化活性进行研究。方法采用XRD,SEM,BET和UV-Vis DRS等手段对其晶相结构和化学性质进行表征,通过测试该复合结构对罗丹明B的可见光催化降解评估其光催化活性。结果实验结果显示,MoO_3-TiO_2的光催化活性与相应的MoO_3和TiO_2比较,MoO_3-TiO_2光催化剂增强了光催化活性。结论研究表明,光催化活性增强的原因归因于MoO_3和TiO_2形成p-n异质结,抑制了光生电子和空穴的复合。在光催化降解反应中,活性物种h+起主要作用。

Purposes--To study the structure and catalytic activity of MoO3-TiO2 composite photo- catalysts synthesized with hydrothermal method. Methods--Several characterization tools including X- ray powder diffraction （XRD）, scanning electron microscope （SEM）, Brunauer-Emmett-Teller （BET） and UV-Vis diffuse reflectance spectra （UV-Vis DRS） were employed to study the phase structures and optical properties of the as-prepared samples respectively. And their photocatalytic ac- tivities were investigated by the visible light catalytic degradation of rhodamine B （RhB） solution. Results--Compared to the pure MoO3 and TiO2, the MoO3-TiO2 composites exhibited enhanced photo- catalytic activities under visible light irradiation. Conclusion--The heterojunction at the interface be- tween MoO3 and TiO2 can efficiently reduce the recombination of photogenerated electron-hole pairs, which accounts for the enhancement of photocatalytic activity. The active species hole played a leading role in the photocatalytic degradation reaction.