Abstract: Industrial organic wastewater pollution endangers human health and hinders economic development, which is an urgent problem to be solved. Metal-organic framework (MOFs) material is expected to be a potential new material for industrial organic wastewater treatment because of its unique pore structure, large specific surface area and excellent adsorption performance. Due to its complex SOD topological structure and high stability, ZIF-8 (zeolite imidazole ester skeleton-8) has attracted more and more attention to its application value in industrial wastewater adsorption. In this paper, the optimal phase ratio of anatase/rutile mixed phase TiO₂ nanoparticles were firstly prepared by the sol-gel method and temperature regulation, and the coated type ZIF-8 composite material was prepared by in-situ growth on the surface of the TiO₂ particles by the solvent method. The results show that the degradation rate and reaction rate of methylene blue (MB) pollutants in the composite material constructed by introducing 10% (mass fraction) TiO₂ and ZIF-8 follow the first-order kinetic model, which are 1.27 times and 2.3 times that of pure ZIF-8, respectively. The controlled preparation of the uniformly distributed Zn/ZnO_x nano-heterojunctions in the pores of the ZIF-8 organic framework materials served as the activation site, which increases the contact area with MB molecules and the capture number of carriers. At the same time, TiO₂ and the exposed highly active heterojunction interface formed a synergistic enhancement effect and a stereoscopic catalytic degradation complex system, which enhances the catalytic degradation ability.

Key words: TiO₂@ZIF-8, organic wastewater, catalytic degradation, heterojunction, synergistic enhancement