Kumaravel, SaranrajSaranrajKumaravelKumaravel, SakthivelSakthivelKumaravelChandramoorthy, ChandrasatheeshChandrasatheeshChandramoorthyDurai, MathivananMathivananDuraiArun ThirumuruganSandoval-Hevia, GabrielaGabrielaSandoval-HeviaSomu, PrathapPrathapSomuAfzal, MohdMohdAfzalDurai, ManiManiDuraiLiu, Chuan-MingChuan-MingLiu2026-07-072026-07-072026SEPARATION AND PURIFICATION TECHNOLOGY, 380, 135332 (2026). https://doi.org/10.1016/j.seppur.2025.1353321383-58661873-3794https://hdl.handle.net/20.500.12740/24715Designing efficient dual-functional catalysts for the oxygen evolution reaction (OER) and the removal of organic pollutants from wastewater remains a major challenge in sustainable energy technology. In this study, g-C3N5, 5 % Br-g-C3N5, alpha-Fe2O3, alpha-Fe2O3@g-C3N5 (FCN), and alpha-Fe2O3@5 % Br-g-C3N5 (BFCN) composites were synthesized via an in situ solvothermal process. The performance of these materials was systematically evaluated for their electrocatalytic OER in an alkaline medium (1.0 M KOH) and for their photocatalytic degradation of norfloxacin (NOR) under white light-emitting diodes (LED) illumination. Notably, the alpha-Fe2O3@5 % Br-gC3N5@Nickel foam (BFCN@NF) composites exhibited a low overpotential (eta) of 270 mV at 10 mA/cm2 and a Tafel slope of 62 mV/dec, comparable to commercial IrO2@NF and superior to other fabricated catalysts. Moreover, this composite demonstrated excellent photocatalytic degradation of NOR, achieving a 95 % removal rate within 105 min of LED irradiation and maintaining stable performance over the 10th consecutive cycles. The identification of intermediate products by liquid chromatography-mass spectrometry (LC-MS) facilitated the proposition of plausible degradation pathways. Moreover, overall water splitting (OWS) electrolyzer assembled with BFCN@NF & Vert;"BFCN@NF electrodes operated at a low cell voltage of 1.58 V at 10 mA/cm2 and maintained stable performance for more than 100 h of continuous operation. These results are attributed to the strong synergistic effect of alpha-Fe2O3 and Br-g-C3N5, which enhances the density of surface-active sites and electrical conductivity. Overall, this catalytic system shows great potential for applications in green energy conversion and environmental purification."ElectrocatalystPhotocatalystOverall water splittingNorfloxacinLED lightalpha-Fe 2 O 3 @Br-g-C 3 N 5Articulohttps://doi.org/10.1016/j.seppur.2025.135332