Facile synthesis of MOF-808/AgI Z-scheme heterojunction with improved photocatalytic performance for the degradation of tetracycline hydrochloride under simulated sunlight

Abstract

The MOF-808/AgI (MA) photocatalyst was synthesized through a plain ion-exchange precipitation means. The crystalline phase structure, microcosmic appearance, elemental composition and optical performance of the catalyst were tested by XRD, SEM, TEM, XPS, UV-vis DRS, EIS, PL and ESR techniques. Tetracycline hydrochloride (TC) was selected as the simulated contaminant for photodegradation experiments to estimate the photocatalytic properties of the as-prepared materials. The results suggested that the degradation performance of the MA compounds was significantly enhanced, and the composite with a AgI loading of 40% (MA-40) showed the best degradation performance with a 93.65% degradation rate in 80 min. Furthermore, the radical capture experiments proved that ˙O₂⁻, ¹O₂ and h⁺ were the principal active intermediates in the photochemical catalysis process. Therefore, it can be speculated that the loading of AgI enhanced the visible light absorption and a Z-scheme heterojunction between the two components was formed, which promoted the separation of photogenerated carriers.