MOF-derived C-doped ZnO composites for enhanced photocatalytic performance under visible light

Abstract

Carbon-doped zinc oxide (ZnO) with porous structure was synthesized by pyrolysis of a zinc-based metal organic framework (MOFs). Photocatalytic effect was measured by the photodegradation of Rhodamine B (RhB) under visible light irradiation. The morphology, structure, and porous properties of the as-synthesized composites were characterized by using field emission scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), the thermogravimetric and differential scanning calorimetry analysis (TG-DSC), diffuse reflectance UV–vis spectroscopy (UV–vis DRS), photoluminescence (PL) and N2 sorption-desorption isotherms (BET). Compared with other conventional C-doping methods, MOF sacrificial template method not only retains the porous structure with interconnected ZnO nanoparticles but also introduces carbon doping evenly in ZnO lattice which reduces the band gap of ZnO and thus improves the charge-separation efficiency. The trapping experiment results showed that superoxide radicals (O2−) and photoexcited hole (h+) are the main and minor oxidative species in the photodegradation of RhB respectively. And the enhanced photocatalytic mechanism was also proposed.