Bi2MoO6/BiVO4异质结的水热合成和可见光催化活性

采用一步水热法制备Bi₂MoO₆/BiVO₄复合光催化剂. 利用X 射线衍射(XRD)、场发射扫描电子显微镜(FESEM)、高分辨透射电子显微镜(HRTEM)等手段对其晶体结构和微观结构进行了表征. 结果表明, Bi₂MoO₆纳米粒子沉积在BiVO₄纳米片表面从而形成异质结结构. 紫外-可见漫反射光谱(UV-Vis DRS)表明所制备的Bi₂MoO₆/BiVO₄异质结较纯相Bi₂MoO₆和BiVO₄对可见光吸收更强. 由于形成异质结结构及其光吸收性能使Bi₂MoO₆/BiVO₄ 光催化活性有较大提高. 可见光下(λ>420 nm)光催化降解罗丹明B (RhB)实验结果表明,Bi₂MoO₆/BiVO₄光催化活性较纯相Bi₂MoO₆和BiVO₄高. Bi₂MoO₆/BiVO₄样品光催化性能提高的原因是Bi₂MoO₆和BiVO₄形成异质结, 从而有效抑制光生电子-空穴对的复合, 增大了可见光吸收范围及比表面积.

Hydrothermal Synthesis and Efficient Visible Light Photocatalytic Activity of Bi2MoO6/BiVO4 Heterojunction

A Bi₂MoO₆/BiVO₄ photocatalyst with a heterojunction structure was synthesized by a one-pot hydrothermal method. Its crystal structure and microstructure were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HRTEM). The FESEM and HRTEM images indicated that Bi₂MoO₆ nanoparticles were loaded on the surface of BiVO₄ nanoplates to form a heterojunction. The ultraviolet visible (UV-Vis) diffuse reflection spectra (DRS) showed that the resulting Bi₂MoO₆/BiVO₄ heterojunction possessed more intensive absorption within the visible light range compared with pure Bi₂MoO₆ and BiVO₄. These excellent structural and spectral properties endowed the Bi₂MoO₆/BiVO₄ heterojunction with enhanced photocatalytic activity. It was found that the Rhodamine B (RhB) degradation rate with Bi₂MoO₆/BiVO₄ was higher than that with pure BiVO₄ and Bi₂MoO₆ under visible light (λ>420 nm) by photocatalytic measurements. The enhanced photocatalytic performance of the Bi₂MoO₆/BiVO₄ sample can be attributed to the improved separation efficiency of photogenerated hole-electron pairs generated by the heterojunction between Bi₂MoO₆ and BiVO₄, intensive absorption within the visible light range, and high specific surface area.