Fast adsorption combined with Z-scheme charge migration in ZIF-8/CeO2 enables efficient photocatalytic performance

Constructing a heterostructure is a key factor in effectively enhancing photocatalytic activity. In this paper, CeO₂ was tightly anchored on the surface of ZIF-8 through a simple co-precipitation method, successfully constructing a Z-scheme heterostructure and accelerating the separation of photogenerated carriers. The photocatalytic activity was evaluated by eliminating RhB and MB with the assistance of visible light. The results showed that the optimized ZC2 exhibited better photocatalytic degradation ability than pure ZIF-8 and CeO₂, with a degradation rate of 92.8 % and 85.38 % for RhB for MB within 90 min. The improvement of the photocatalytic ability of the ZC series is due to constructing a Z-scheme heterostructure between ZIF-8 and CeO₂, resulting in effectively reduced interface impedance and increased the separation of photogenerated electron-hole pairs and improving the electron utilization rate. Moreover, the increase in the specific surface area of the composite material provides more active sites for reactants and more possibilities for degrading organic pollutants. The coexistence of multiple free radicals was proved by free radical trapping experiments to achieve efficient degradation of pollutants. In addition, this paper will discuss in detail the transfer of photogenerated carriers and the possible photocatalytic mechanism.