Sunlight active cellulose/g-C3N4/TiO2 nano-photocatalyst for degradation of industrial dye and pharmaceutical drug in real wastewater

The paper critically addresses two contemporary environmental challenges: the water crisis and the unrestricted discharge of organic pollutants in waterways together. An eco-friendly method was used to fabricate a cellulose/g-C3N4/TiO2 photocatalytic composite that displayed a remarkable degradation of methylene blue dye and atenolol drug under natural sunlight. Introducing graphitic carbon nitride (g-C3N4) onto pristine TiO2 improved hybrid material’s photonic efficacy and enhanced interfacial charge separation. Furthermore, immobilizing TiO2/g-C3N4 on a semi-interpenetrating cellulose matrix promoted photocatalyst recovery and its reuse, ensuring practical affordability. Under optimized conditions, the nano-photocatalyst exhibited ~95% degradation of both contaminants within two hours while retaining ~55% activity after ten cycles demonstrating a promising photostability. The nano-photocatalyst causes 66% and 57% reduction in COD and TOC values in industrial wastewater containing these pollutants. The photocatalysis was fitted to various models to elucidate the degradation kinetics, while LC-MS results suggested the mineralization pathway of dye majorly via ring opening demethylation. >98% disinfection was achieved against E. coli (10-105 CFU∙mL-1) contaminated water. This study thus paves multifaceted strategies to treat wastewater contaminants at environmental levels employing nano-photocatalysis.