Hybrid photocatalysts using semiconductor/MOF/graphene oxide for superior photodegradation of organic pollutants under visible light

A novel Bi2O3/MOF/GO composite photocatalyst was prepared by a facile method, and characterized by XRD, SEM, EDS, FT-IR, BET, UV-Vis DRS and PL spectrum. The as-prepared Bi2O3/MOF/GO composites displayed the standout photocatalytic activity towards the degradation of Rhodamine B (RhB) under visible light irradiation. The introduction of MOF and graphene oxide into semiconductor Bi2O3 enhanced the photocatalytic activity dramatically, and the topgallant composite referred to BCG-2, which showed the highest photocatalytic activity. In the light of the active species trapping experiments, the OH and O2- radicals were the two main active radicals in the photocatalytic tests. The enhanced photocatalytic performance is chiefly ascribed to the formation of the tight joint interface in Bi2O3/MOF/GO composites, among which GO with the excellent conductivity and MOF with the certain adsorption effect during the photodegradation process. This synergistic effect is propitious to the transfer and separation of photo-generated carriers. At the same time, the Bi2O3/MOF/GO composite photocatalyst can maintain a stable photocatalytic activity and structure after three cycles. Finally, the possible mechanism of photocatalytic degradation of RhB was put forward.