Microwave-based preparation of γ-Fe2O3/SrTiO3 photocatalyst for efficient degradation of organic pollutants in water

Abstract

Photocatalysis is considered one of the most promising wastewater treatment technologies. In this work, a magnetic photocatalytic γ-Fe2O3/SrTiO3 composite with high performance and stability were synthesized by a one-step microwave method, and the amount of γ-Fe2O3 on methylene blue (MB) and tetracycline (TC) degradation performance of composite photocatalyst was investigated under simulated sunlightand. The materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible diffuse reflectance spectra (UV–vis DRS) and electron spin resonance (ESR). The degradation of MB and TC over 0.3% γ-Fe2O3/SrTiO3 was found to be very effective, and the degradation reached 84.91% (150 min) and 92.03% (60 min), respectively. After five consecutive cycles of reusability test under visible light irradiation, the photocatalytic degradation efficiency remained unchanged. According to the results of free radicals capture experiments and ESR, superoxide radical and hole were found to be the main active species for MB degradation. The degradation products were identified by liquid chromatography triple quadrupole mass spectrometry (LC-MS), and a possible degradation pathway of TC was proposed. Thus, magnetic composites provide a new strategy for the design of photocatalysts with excellent catalytic performance, which is conducive to recovery.