Sunlight active cellulose/g-C3N4/TiO2 nano-photocatalyst for simultaneous degradation of methylene blue dye and atenolol drug in real wastewater

Abstract

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 caused 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 (104–105 CFU·ml−1) contaminated water. This study thus paves multifaceted strategies to treat wastewater contaminants at environmental levels employing nano-photocatalysis.