Graphitic carbon nitride engineered α-Fe2O3/rGO heterostructure for visible-light-driven photochemical oxidation of sulfamethoxazole

[Display omitted] •A novel g-C3N4/Fe2O3/rGO ternary composite was synthesised using a hydrothermal process.•The catalyst exhibits a high photocatalytic oxidation efficiency for the removal of sulfamethoxazole.•Reactive oxygen species were identified by quenching tests and electron paramagnetic resonance spectra.•Detailed mechanistic studies were performed to deduce the radical and non-radical degradation pathways. Rational design of semiconductor photocatalysts is an effective way to achieve efficient visible-light-driven environmental remediation. Herein, a series of graphitic carbon nitride (g-C3N4) engineered hematite (Fe2O3)/reduced graphene oxide (rGO) photocatalysts were synthesised and employed in visible-light-driven photo-Fenton-like degradation of sulfamethoxazole (SMX). The exceptional performance of the optimal photocatalyst (0.4-FerGCN-3) was achieved because of the successful structural integration of g-C3N4/Fe2O3/rGO for efficient separation and migration of photoinduced charge carriers (e−/h+). Photochemical decomposition efficiency was also optimised by analysing the important reaction parameters such as initial catalyst loading, initial H2O2 dosage, pH, and reaction temperature. Detailed studies on the generation of reactive species and degradation intermediates were performed to propose a possible mechanism for SMX degradation. The findings may provide not only a strategy for nanostructure engineering of semiconductor photocatalysts but also insights into the effective remediation of emerging contaminants such as SMX.