Enhanced synergistic photocatalytic degradation of oxytetracycline antibiotic using novel Ag2MoO4/Co-zeolitic imidazolate framework (ZIF-67) Z-type heterojunction

Abstract

Enabling efficient separation of photocarriers is a critical approach for the development of high-performance photocatalyst systems to efficiently remove environmental contaminants. Herein, a novel heterojunction of Co-zeolitic imidazolate framework (ZIF-67) assembled on Ag2MoO4 has been developed using simple solvothermal and precipitation routes. The structure, composition, morphological, and surface and optical features of asprepared Ag2MoO4/ZIF-67 photocatalyst were determined by XRD, EDX, XPS, FESEM, TEM, PL, EIS, UV–vis DRS and BET analytical methods. The activity of developed composite photocatalyst was evaluated by photodegradation of a pharmaceutical oxytetracycline (OTC) under simulated visible light, in which 98.2% of was photodegraded by Ag2MoO4/ZIF-67 within 75 min. The improved photocatalytic performance of Z-type Ag2MoO4/ZIF-67 heterojunction is due to the active electron-hole separation, charge transfer between Ag2MoO4 and ZIF-67, and therefore, degradation efficiency enhanced via increasing the production of radicals. Moreover, the active species trapping experiments approved that •O2– and h+ were the most critical species, and reinforced the suggested photocatalytic mechanism of Ag2MoO4/ZIF-67 Z-type system.