Incorporation of CuWO4 With Hollow Tubular g-C3N4: Harnessing the Potential in Photocatalytic Degradation, Hydrogen Production, and Supercapacitor Applications

Abstract

Driven by the urgent need for sustainable energy conversion and environmental remediation technologies, the development of multifunctional materials has gained growing interest. Herein, a bifunctional heterostructure was fabricated by depositing copper tungstate (CuWO<inf>4</inf>) spherical particles over hollow tubular graphitic carbon nitride (HTCN) using an ultrasonic-assisted thermal impregnation method. The photocatalytic activities were evaluated through tetracycline degradation and hydrogen evolution tests, while electrochemical measurements were conducted to assess the supercapacitor performance. CuWO<inf>4</inf>@HTCN composite achieved up to 83% degradation efficiency, a hydrogen evolution rate of 2538 μmol g1 h−1, and a specific capacitance of 212 F g1, demonstrating its strong potential as a multifunctional material for solar-driven environmental and energy storage applications. The enhanced photocatalytic performance was attributed to extended visible light absorption ability, efficient charge separation, and suppressed electron–hole recombination resulting from the formation of a Z-scheme heterojunction. Furthermore, the superior capacitance behavior was ascribed to enhanced electrical conductivity and ion transport, enabled by the porous, nitrogen-rich HTCN structure. The increased HTCN content in the composite improved pore accessibility and active site availability while an excessive amount of CuWO<inf>4</inf> reduced electrochemical performance. These results highlight the multifunctional applicability of CuWO<inf>4</inf>@HTCN composite in photocatalytic hydrogen production and supercapacitor systems, emphasizing their relevance for renewable energy technologies. © 2025 Elsevier B.V., All rights reserved.