Abstract

Addressing the growing challenge of water pollution, this study reports the development of an advanced WO3/g-C3N5 composite photocatalyst synthesised through a solid-state mixing approach. Comprehensive characterisation techniques confirmed the successful incorporation of WO3 nanoparticles into the g-C3N5 matrix. Optical band-gap analysis revealed a significant narrowing, which enhanced the composite's visible-light absorption. The WO3/g-C3N5 photocatalyst demonstrated excellent photocatalytic performance, achieving 92.2% degradation of congo red within 100 min and 94.3% degradation of malachite green within 120 min. Radical scavenging experiments indicated that hydroxyl radicals (center dot OH) and photogenerated holes (h+) were the dominant reactive species responsible for dye degradation. In addition, the composite exhibited good stability and reusability, retaining its photocatalytic efficiency over five successive cycles. These results highlight the potential of the WO3/g-C3N5 composite as an efficient and sustainable photocatalyst for advanced wastewater treatment applications. (c) 2026 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan. All rights are reserved, including those for text and data mining, AI training, and similar technologies.