Ultrathin graphene oxide encapsulated in uniform MIL-88A(Fe) for enhanced visible light-driven photodegradation of RhB

It is very important to design excellent heterojunction structure for the improvement of the photocatalytic performance. In this study, we report a facile approach of polymerizing the ultrathin graphene oxide on the surface of the MIL-88A(Fe) to form MIL-88A(Fe)/grapheme oxide composite for enhancing the photocatalytic efficiency of organic molecules degradation. The optical grapheme oxide doping content in MIL-88A(Fe)/grapheme oxide hybrid is determined to be 9.0 wt%, which increases the surface area of the MOFs from 15.9 m(2)g(-1) to 408.9 M(2)g(-1) due to the emerging micropores, and the corresponding photocatalytic rate for RhB is 8.4 times higher than that of pure MIL-88A(Fe). Meanwhile, DMF-free MOF-based heterostructure could avoid secondary contamination in the photocatalytic application process, and the degree of RhB removal is maintained at about 100% after the five cycles of the reaction. Integrating the related electrochemical analysis and the active species trapping experiments, the decisive factors for the improved photocatalytic efficiency of MIL-88A(Fe)/grapheme oxide may be the unique structural advantages of ultrathin grapheme oxide sheets, compact and uniform interface contact, more adsorption sites and more reaction sites. This work provides a novel sight for preparing high-efficient and environment-stable photocatalysts by designing the surface heterojunction structure.