Efficient Visible-Light Photocatalysis Using Fe-Doped SnO2/Chitosan Composite for Organic Pollutant Degradation: Mechanisms, Reusability, and Sustainability

Abstract

Water pollution induced by organic dyes offers serious environmental and health problems, necessitating the development of effective and sustainable photocatalysts for wastewater treatment. This work successfully produced a novel Fe-doped SnO₂ supported on chitosan (Fe@SnO₂/Chitosan) composite via a co-precipitation process and assessed for its photocatalytic effectiveness in degrading organic dyes under visible light. Comprehensive structural, morphological, and optical characterizations verified the successful inclusion of Fe doping and Chitosan, leading to a lowered bandgap of 2.73 eV and delayed charge carrier recombination. The average particle size was 16.1 nm, and the X-Ray Photoelectron Spectroscopy (XPS) analysis confirmed the presence of Fe in the + 3 state, which resulted in enhanced photocatalytic activity. The composite displayed excellent degradation efficiencies of 87.3% for methylene blue (MB) and 99.8% for rose bengal (RB) utilizing a low catalyst dosage and without the requirement for oxidizing agents. Scavenger investigations demonstrated the key function of hydroxyl and superoxide radicals in the photodegradation pathway. Additionally, reusability studies validated the composite’s high stability and efficiency across several cycles. The Fe-doped SnO₂/Chitosan (Fe@SnO₂/Chitosan) composite presents a sustainable, cost-effective solution for advanced wastewater treatment, giving tremendous promise for large-scale applications.