Improved sunlight-driven photocatalytic abatement of tetracycline and photoelectrocatalytic water oxidation by tin oxide quantum dots anchored on nickel ferrite nanoplates

Abstract

In this study, nickel ferrite (NiFe2O4) was prepared by a simple wet chemical procedure followed by calcination, and tin oxide (SnO2) quantum dots (SQDs) were prepared by a chemical reduction approach. Additionally, a NiFe2O4–SQD (NF–SQDs) nanocomposite was prepared by a hydrothermal approach. The NF–SQDs nanocomposite was analyzed using several techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), and electrochemical investigations. The NF–SQDs nanocomposite showed promising properties for use as a novel nanomaterial in the degradation of the water pollutant, tetracycline (TC), and was used for photoelectrochemical (PEC) water oxidation. The successful preparation of the NF–SQDs nanocomposite was confirmed by XRD, SEM, TEM, and DRS. Morphology analysis confirmed the successful decoration of SQDs on the NiFe2O4 nanoplates. The bandgap of the NF–SQDs nanocomposite was modified because of the formation of a heterojunction. The NF–SQDs nanocomposite degraded TC within 70 min under simulated sunlight irradiation and effectively separated the photogenerated charge carriers to improve the degradation efficiency. Detailed PEC investigations revealed a low charge-transfer resistance, excellent photocurrent response, and high stability of the NF–SQDs nanocomposite. The detailed potential mechanisms for the photocatalytic degradation of TC and PEC water oxidation are discussed herein with schematics.