Solar Light-Induced Photocatalytic Response of BiOCl/PANI Composite towards the Degradation of Tetracycline

Abstract

Photocatalytic degradation has gained much attention as a means of reducing water contamination as, with increasing industrialization and population growth, water pollution is a menace to both individuals and the environment. In this respect, metal oxide photocatalysts demonstrate effectiveness due to their excellent properties, such as their narrow band gap and low recombination rate of charge carriers. Here, various weight ratios of BiOCl/PANI composites have been synthesized by the simple wet chemical method. The crystallinity, oxidation state and surface chemical composition of the elements were analyzed by XRD and XPS techniques. FESEM and HRTEM images verified the formation of BiOCl nanosheets, covered well with PANI nanofibers, while EDX spectra revealed the uniform distribution of elements. The high surface area of the photocatalyst with a mesoporous nature was revealed by BET analysis. Low recombination rate and narrow band gap, suitable for photocatalysis, were confirmed by PL and UV–DRS spectroscopy. The photocatalytic performance of the photocatalyst was tested for the photodegradation of rhodamine-B (Rh-B) and tetracycline (TC) under natural sunlight irradiation. Kinetic results demonstrated that the 15% BiOCl/PANI hybrid exhibits excellent photocatalytic activity, degrading 97% of Rh-B and 77% of TC with a high rate constant (for Rh-B 0.0236 min−1 and for TC 0.0106 min−1). Trapping experiments highlighted that O2•− radicals play a vital role in the photodegradation mechanism. The reusability studies confirmed the good stability of the catalyst for the degradation of Rh-B (~85%) after five sequential runs. Considering its superior properties and ease of preparation, the synthesized photocatalyst can be used for ecological remediation.