Visible Light-Driven Photocatalytic Activity of Magnetic Recoverable Ternary ZnFe2O4/rGO/g-C3N4 Nanocomposites

Abstract

ZnFe2O4/rGO/g-C3N4 ternary nanocomposite photocatalysts with different ZnFe2O4/g-C3N4 weight ratio (0.5, 0.75, 1) were prepared by a stepwise solvothermal method using ethylene glycol as the solvent. Physicochemical methods such as X-ray diffraction, UV-Vis diffuse reflectance spectroscopy and photoluminescence spectroscopy were applied in order to characterize the composites. The formation of a meso-/macroporous structure with specific surface area between 67 and 77 m2 g–1 was confirmed by N2 adsorption/desorption. The bandgap of the composites was found to be lower (2.30 eV) than that of g-C3N4 (2.7 eV). In contrast to pure g-C3N4, the composites showed no fluorescence, i.e. no recombination of e–/h+ took place. All samples, including pure g-C3N4 and ZnFe2O4, were tested for adsorption and photocatalytic degradation of aqueous malachite green model solutions (10–5 M) under visible light irradiation (λ > 400 nm). The results show that the prepared nanocomposites have higher absorption and photocatalytic activity than the pristine g-C3N4 and ZnFe2O4 and can be successfully used for water purification from organic azo-dyes.

Recent advances in spinel ferrite-based magnetic photocatalysts for efficient degradation of organic pollutants

“…It is believed that the combination of heterojunction and graphene can greatly enhance photocatalytic efficiency (Hafeez et al 2023). In 2020, Tsvetkov et al reported the ternary ZnFe 2 O 4 /rGO/g-C 3 N 4 nanocomposite (Tsvetkov et al 2020), prepared by the solvothermal method. During the photodegradation process, rGO (reduced GO) acted as an electron mediator, and efficiently separated photo-induced charge carriers (e À /h þ ), it also enhanced the adsorption ability to target pollutants.…”