Implementation of visible light-driven photocatalytic degradation of antibiotic chloramphenicol using Bi2S3/ZrO2 and Bi2WO6/ZrO2 heteronanostructures

Abstract

Zirconium dioxide-incorporated bismuth sulfide (Bi2S3/ZrO2) and bismuth tungstate (Bi2WO6/ZrO2) heteronanostructures (HNSs) were fabricated to serve as photocatalysts for the visible light-driven degradation of antibiotic chloramphenicol (CAP). A two-step hydrothermal process was applied to synthesize HNSs, and their structural and optical properties were validated by several analytical techniques. Interestingly, a multi-structural feature was ascertained in which nanoflower-structured ZrO2 was attached to the surface of nanorod- and nanosheet-structured Bi2S3 and Bi2WO6, respectively, resulting in the formation of Bi2S3/ZrO2 and Bi2WO6/ZrO2 HNSs. For the photocatalytic degradation of CAP, both HNSs showed magnificent catalytic activity during a visible light-based photocatalytic degradation. Furthermore, when peroxymonosulfate (PMS) was used as an activator for an oxidative catalytic reaction, the photocatalytic degradation rate was drastically enhanced to nearly 5 times. Bi2S3/ZrO2 and Bi2WO6/ZrO2 showed ∼96 % CAP degradation in 15 min, with rate constants of 0.2511 and 0.2163 min−1, respectively. The synergistic effects of the substantial generation and separation of photoinduced charge carriers are responsible for the highly improved catalytic activity. Scavenger analysis demonstrated that hydroxyl radical species predominated in the effective degradation process. These kinds of inorganic-based HNSs are expected to rule the field of contaminated water remediation, which will also expand a platform for the fabrication of photocatalyst materials.