Efficient solar-light photodegradation of tetracycline hydrochloride using BiVO4/MoO3 composites

Abstract In recent years, photocatalysis has been confirmed as an emerging route to eliminate the contaminants such as dyes, antibiotics, and heavy metals from wastewater. To explore MoO3-based photocatalyst with excellent photocatalytic activity, BiVO4-modified hexagonal h-MoO3 (BiVO4/MoO3) composites were constructed for solar-light induced photodegradation of tetracycline hydrochloride (TCH) via a chemical precipitation approach. Compared with pure h-MoO3, BiVO4/MoO3 exhibited the inferior adsorption capacity while efficient photocatalytic activity. The removal efficiency of TCH over BiVO4/MoO3 was affected by BiVO4 content, pH, and inorganic ions. For optimal 3-BiVO4/MoO3 with a BiVO4 content of 4.25%, the adsorption-photocatalytic efficiency of 190 mg L−1 TCH was 97.66% within 160 min, and decreased to 91.35% after five cycles under the same conditions. The quenching experiments indicated that h+ and·O2- served as the main species in adsorption-photocatalytic system. The tight junction interface between BiVO4 and MoO3 could enhance the visible-light response and the transfer and separation of photoinduced electron-hole pairs. Hence, the excellent activity and durability of BiVO4/MoO3 was favorable for the adsorption-photodegradation of organic pollutants.