Liquid phase deposition of flower-like TiO2 microspheres decorated by ZIF-8 nanoparticles with enhanced photocatalytic activity

In this study, the liquid phase deposition of flower-like TiO2 microspheres were decorated by ZIF-8 nanoparticles, forming the ZIF-8/TiO2 composite materials. The results showed that the ZIF-8 nanoparticles can be well-deposited on the surface of TiO2 microspheres with a porous microstructure. The photocatalytic activity of the as-prepared materials were evaluated by the degradation of methylene blue (MB) and rhodamine B (RhB) solutions. It revealed that the ZIF-8/TiO2 composite materials exhibited the enhanced photocatalytic activity, of which the photodegradation rate of MB and RhB solutions with initial concentration of 10 mg/L can reach approximately 90% under illumination for 40 min. Moreover, the reactive species trapping experiments indicated that ·OH was the main active species during the photodegradation process in this system. The enhanced photocatalytic activity of ZIF-8/TiO2 composite materials was attributed to the synergistic effect between the TiO2 microspheres and ZIF-8 nanoparticles, which resulted in the increased specific surface area and the reduced recombination of photogenerated charge carriers.