Enhanced photocatalytic water splitting for green hydrogen production and enrofloxacin degradation using a novel In2S3-Based ternary photocatalyst: Fabrication and mechanism insights

The development of efficient photocatalysts is pivotal for advancing solar-driven processes, particularly for simultaneous pollutant degradation and hydrogen (H2) generation. In this study, a novel Fe2Os/Bi2Os/In2Ss (FB/ IS) heterojunction photocatalyst was synthesized via a facile preparation method. The optimized 30-FB/IS composition (3o wt.% loading of Fe2Os/Bi2Os/ on the In2Ss) exhibited superior photocatalytic performance under visible light irradiation, achieving a hydrogen production rate of 590.36 mu mol center dot g-1 center dot h-1 and a 98 % degradation efficiency for Enrofloxacin (ENX). Detailed morphological, structural, optical and electrochemical characterization using SEM, XRD, XPS, TEM, BET, photocurrent response, Mott-Schottky, PL, EIS, and ESR techniques confirmed the formation of an S-scheme heterojunction, which efficiently enhanced charge separation and minimized electron-hole recombination. The 30-FB/IS catalyst demonstrated optimal kinetics, with a rate constant of 0.043 min-1 for ENX degradation, outperforming binary and single-component catalysts. ESR and scavenging experiments identified hydroxyl radicals (center dot OH) and superoxide radicals (center dot O2-) as the primary reactive species driving the degradation process. Furthermore, LC-MS analysis revealed three potential degradation pathways for ENX. The photocatalyst showed excellent stability, retaining 85 % of its initial activity after five cycles, and demonstrated broad-spectrum pollutant degradation, including in real water samples. These findings underscore the potential of the FB/IS heterojunction system for practical applications in both clean energy production and environmental remediation.