Metal organic framework-derived Zn1−xCox-ZIF@Zn1−xCoxO hybrid photocatalyst with enhanced photocatalytic activity through synergistic effect

Abstract

A Zn_1−xCo_x-ZIF@Zn_1−xCo_xO hybrid photocatalyst, doped with different amounts of Co, was successfully fabricated through a novel metal organic framework (MOF)-derived method. The synthesis procedure consists of the initial preparation of Zn_1−xCo_x-ZIF and then the formation of Zn_1−xCo_xO via Zn_1−xCo_x-ZIF-derived in situ transformation with AgNO₃ to obtain the Zn_1−xCo_x-ZIF@Zn_1−xCo_xO hybrid photocatalyst. All samples were characterized by XRD, SEM, TEM, UV-vis, and FT-IR. The photocatalytic activity of all samples was evaluated by degradation of rhodamine B (RhB) solution under UV light and visible light. The results show that Zn_1−xCo_x-ZIF@Zn_1−xCo_xO hybrid photocatalysts exhibit high photocatalytic activity, and the doping of Co has great influence on the photocatalytic activity of Zn_1−xCo_x-ZIF@Zn_1−xCo_xO. Among these photocatalysts, Zn_0.95Co_0.05-ZIF@Zn_0.95Co_0.05O exhibits the highest photocatalytic activity. Zn_0.95Co_0.05-ZIF@Zn_0.95Co_0.05O can degrade 99.26% RhB under UV light, which is even higher than P25 (92.62%). Zn_0.95Co_0.05-ZIF@Zn_0.95Co_0.05O also exhibits a photoresponse to visible light, and was able to degrade 98.15% RhB under visible light irradiation. Furthermore, Zn_0.95Co_0.05-ZIF@Zn_0.95Co_0.05O also can degrade 95.83% RhB under visible light after four repeated cycles. The results indicate that Zn_0.95Co_0.05-ZIF@Zn_0.95Co_0.05O can be used as a highly efficient photocatalyst upon degradation of organic dye.