Rapid construction of inverse opal structured ZnO/ZIF-8 heterostructure films with multi-stage pore structure for highly efficient purification of wastewater through piezo-photocatalysis

A novel method was established to create ZnO/ZIF-8 core/shell heterostructured film piezo-photocatalysts for highly efficient removal of pollutants from water. This method was inspired by distinctive pore structure of ZIF-8 and has the advantage of simple and quick synthesis. In this work, ZnO/ZIF-8 heterostructure thin films were created by growing ZIF-8 metal organic framework in-situ on inverse opal structure ZnO films, which also served as the porous template and zinc source of ZIF-8 simultaneously. Thus, the ZnO/ZIF-8 core/shell heterostructure is composed of ZnO core and ZIF-8 shell. The inverse opal structure enhances the process of light absorption, and the heterostructure is crucial for enhancing the carrier concentration. The ZnO/ZIF-8 heterostructure films exhibit significant degradation capacity towards Rhodamine B (RhB) and tetracycline (TC). Under UV light and ultrasound, the degradation efficiency of ZnO/ZIF-8 heterostructure is much higher than that of ZnO film and ZIF-8 film for RhB solution, indicating that the heterostructure films have a great potential for use in the field of water pollution prevention. This study not only presents an effective method for quickly creating heterostructures, but also demonstrates a path for improving the piezo-photocatalytic efficiency by manipulating the morphology and structure of ZnO/ZIF-8.