Detoxification of emerging contaminants bisphenol A (BPA) and malathion (MLT) through a visible-light-activated...

Bisphenol A (BPA) and Malathion (MLT) are persistent organic pollutants widely detected in aquatic environments, posing significant ecological and human health risks. In this study, a visible-light-responsive photocatalyst based on MnO₂ coupled with defective graphitic carbon nitride (MnO₂/def-g-C₃N₄) was rationally designed for photocatalytic decomposition of 50 mg L^-1 of BPA and 40 mg L^-1 of MLT in water. Structural characterizations viz. XRD, XPS, Mott-Schottky analysis, UV-visible, AFM, SEM and TG-DTA etc. confirmed the successful formation of the p-n heterojunction with abundant surface defects, enhanced light absorption, and improved charge-carrier separation. The optimized MnO₂/def-g-C₃N₄ (DCN-MnO₂) composite exhibited conspicuously suppressed charge recombination and increased photoactivity under visible-light irradiation that showed rapid photodegradation efficiencies of BPA and MLT. The photocatalyst also demonstrated good stability and recyclability over four cycles with minimal activity loss. Mechanistic investigations suggested that the synergistic interaction between MnO₂ and defective g-C₃N₄, along with defect-mediated charge transfer pathways, played a crucial role in enhancing photocatalytic performance. This work highlights MnO₂/def-g-C₃N₄ as an efficient and sustainable visible-light photocatalyst for the decomposition of emerging organic contaminants in wastewater, offering promising potential for environmental remediation applications.