Enhanced photocatalytic NO removal and toxic NO2 production inhibition over ZIF-8-derived ZnO nanoparticles with controllable amount of oxygen vacancies

The controlled introduction of oxygen vacancies (OVs) in photocatalysts has been demonstrated to be an efficient approach for improving the separation photogenerated charge carriers, and thus, enhancing photocatalytic performance photocatalysts. In this study, a two-step calcination method where ZIF-8 was used as precursor explored synthesis ZIF-8-derived ZnO nanoparticles with gradient distribution OVs. Electron paramagnetic resonance measurements indicated that concentration OVs samples depended on temperature treatment process. Ultraviolet–visible spectra supported calcined presented excellent light-harvesting ability ultraviolet-to-visible light range. Moreover, it determined superior removal NO, inhibited generation NO2. These properties could attributed contribution present their performance. electrons confined by transferred O2 generate superoxide radicals, which oxidize NO final product, nitrate. particular, efficiency Z 350-400 (which sample first at 350 °C 2 h, then 400 1 h) 1.5 4.6 times higher than one-step directly °C) commercial ZnO, respectively. findings suggested OV-containing metal oxides derived from metal-organic framework materials hold great promise highly NO.