Construction of co-zeolitic imidazolate framework/Bi2WO6 heterojunction photocatalyst with improved adsorption and photodegradation of ciprofloxacin

Abstract

Refractory pharmaceutical pollutants have become a serious and formidable threat to both human health and the ecosystem. Photocatalysis presents an intriguing approach of using visible light to break down these environmental contaminants directly. Nevertheless, this technique is plagued by a fast combination of the photogenerated charges, which results in poor efficiency and instability. In this work, a novel ZIF-67/Bi2WO6 heterojunction photocatalyst has been developed as an efficient photocatalyst for ciprofloxacin (CIP) degradation under visible-light irradiation. The obtained ZIF-67/Bi2WO6 Z-type heterojunction exhibit dramatically improved visible-light-driven photocatalytic performance compared to pure ZIF-67 and Bi2WO6. Particularly, ZIF-67/Bi2WO6 shows the highest photocatalytic efficiency for the decomposition of CIP, achieving 91.5 %, at 10 mg/L in 90 min. The enhanced photocatalytic performance is attributed to the Z-type heterostructure with strong visible light absorption and effective separation of photoexcited carriers. The scavengers' studies showed that •O2– and •OH radicals have the most effect on the decomposition process. Besides, ZIF-67/Bi2WO6 is endowed excellent durability and stability. Thus, this work shows that ZIF-67/Bi2WO6 may reveal a promising potential for the degradation of several refractory pharmaceutical contaminants.