Rational construction of MOF derived α-Fe2O3/g-C3N4 composite for effective photocatalytic degradation of organic pollutants and electrocatalytic oxygen evolution reaction

In recent years, researchers have been actively investigating metal oxide-based materials with narrow bandgaps due to their potential applications toward wastewater treatment and oxygen evolution reactions (OER). In this study, we successfully synthesized g-C3N4 (GCN), Fe2O3, and Fe2O3/g-C3N4 (FGCN) using thermal polymerization and hydrothermal methods. We characterized the physicochemical and structural properties of these materials through various analytical techniques including XRD, FT-IR, UV-DRS, XPS, FE-SEM, and HR-TEM analyses, confirming the effective construction of the FGCN composite catalyst. We evaluated the photocatalytic activity of Fe2O3, GCN, and FGCN composite catalysts by assessing their ability to degrade rhodamine B (RhB) and crystal violet (CV) by exposing them to sunlight for 150 min. Among these catalysts, the FGCN composite demonstrated excellent photocatalytic performance, achieving 93 % and 95 % degradation of RhB and CV, respectively, under 150 min of sunlight exposure. The developed Fe2O3/g-C3N4@Nickel foam (FGCN@NF) composite catalyst exhibits remarkable OER performance, with a reduced Tafel slope of 64 mV/dec and a low overpotential of 290 mV at a current density of 10 mA/cm2 and shows excellent durable performance over a long time (15 h). Total Organic Carbon (TOC) analysis confirmed the mineralization of both dyes. The photocatalytic performance remained largely unchanged after five consecutive experiments, demonstrating excellent reusability and photostability. Trapping experiments revealed that O2●– is the main species responsible for the photocatalytic decomposition of various dyes by the FGCN composite catalyst. Therefore, the development of a versatile photo/electrocatalytic system that can efficiently promote energy conversion in environmental applications has attracted great attention.