BiVO_4/rGO的水热控制合成及其光催化性能研究

Hydrothermal synthesis and photocatalytic performance of BiVO_4/rGO

以氧化石墨烯(GO)为模板,以乙二胺四乙酸(EDTA)为络合剂,采用水热控制合成方法制备了矾酸铋/还原氧化石墨烯(BiVO_4/rGO)复合光催化剂。利用XRD、FT-IR、SEM、TEM、UV-Vis和BET对BiVO_4/rGO复合光催化剂进行了表征与分析。结果表明,GO较大的比表面积有利于单斜相多面体结构的BiVO_4晶体在其表面的分散,BiVO_4颗粒尺寸约在80~100nm;BiVO_4/rGO的禁带宽度为2.21eV,低于BiVO_4的2.32eV,更利于电子和空穴的产生;BiVO_4的平均孔径为3.54nm,比表面积为12.17m2/g,而BiVO_4/rGO的平均孔径为4.32nm,比表面积为16.04m2/g;BiVO_4/rGO复合光催化剂对亚甲基蓝(MB)的降解在100min达到稳定,降解率为88.49%,而相同条件下的纯BiVO_4对MB的降解率为65.56%,BiVO_4/rGO复合光催化剂的活性更高的原因是rGO为电子受体为光生电子和空穴提供了转移通道,可以抑制电子和空穴的复合。

The BiVO4/reduced graphene oxide （BiVO4/rGO） nanocomposite photocatalyst was synthesized by one-step solvent hydrothermal method using graphene oxide （GO） as carrier and ethylene diamine tetraacetic acid （EDTA） as chelating agent. The obtained BiVO4/rGO photocatalyst was characterized and analyzed by XRD,FT-IR,SEM, TEM, UV-Vis diffuse reflection and BET, respectively. Methylene blue （MB） was degraded to evaluate the performances of the photocatalyst materials. The results show that the monoclinic polyhedron structure of BiVO4 nanoparticles （80-100 nm） was uniformly dispersed on the large reduced graphene oxide （rGO） layers surface.The band-gap of BiVO4/rGO （2.21 eV） was narrower than BiVO4 （2.32 eV）,which is beneficial to the formation of electron-hole pairs,and the pore size and specific surface area of BiVO4/rGO （4.32 nm, 16.04 m^2/g） were higher than these of BiVO4 （3.54 nm, 12.17 m2/g）. The degradation rate of MB （10 mg/ L in aqueous solution） reached to 88.49% in BiVO4/rGO compare with 65.56% in BiVO4 under visible light irradiation in 100 min. The enhancement of photocatalytic activities of BiVO4/rGO photocatalysts can be attributed to rGO providing a transfer channel between photoinduced electron-hole pairs, which restrained the complex of the electron-hole pairs. The effective electron-hole separation by rGO.