Abstract: A cubic  Co₃O₄/SnO₂ composite photocatalyst was prepared by combining do-decahedral nano-blocks derived from metal-organic framework (MOF) material ZIF-67 with SnO₂ at room temperature. Results showed that the band gap of the calcined  Co₃O₄/SnO₂ material was significantly reduced, and the phenomenon of fluorescence quenching was obvious. The addition of Co3O4 expanded the photoresponse range of SnO₂ to visible light or even infrared light and simultaneously promoted the separation of photo-generated carriers during the photocatalytic reaction. With Rhodamine B (RhB) used as the target reactant, the photocatalytic degradation activity of  Co₃O₄/SnO₂ derived from the MOF was investigated under visible light. It was found that  Co₃O₄/SnO₂ could degrade 89.6%RhB within 60 min, which was 4.5 and 3 times greater than those of pure SnO2 and pure ZIF-67, respectively. In addition, Co3O4/SnO2 showed good photoreactivity and stability. Based on these experimental results and those from free-radical quenching experiments, the mechanism of photocatalytic degradation of organic dyes RhB by the MOF-derived Co3O4/SnO2 composite material was proposed.

Key words: Co₃O₄/SnO₂, Metal Organic Framework (MOF), Photocatalytic, Mechanism