Fabrication of Ag-decorated CuWO4 nanoparticles for photocatalytic degradation of crystal violet in water

The widespread release of industrial dyes into aquatic systems poses serious environmental hazards and public health concerns. Addressing this challenge serves as an impetus for the search for sustainable means of environmental remediation. Herein, a series of visible light active Ag-modified CuWO 4 photocatalysts, with varying silver loadings (1, 5, and 10 wt%), were synthesized through a simplified hydrothermal approach and their properties were studied using XRD, SEM, EDX, EIS, TEM, FTIR, UV–vis spectroscopy, and photoluminescence (PL) analyses. This novel study presents a systematic evaluation of Ag loading on the structural and photocatalytic behaviour of CuWO 4 , providing insights into the relationship between dopant concentration, charge-carrier dynamics, and photocatalytic performance. As a result, photocatalytic evaluation of crystal violet (CV) revealed that the Ag-CuWO 4 system exhibited markedly improved photoactivity for dye degradation. Among the nanoparticles, 5 wt% Ag-loaded CuWO 4 demonstrated the highest degradation activity of 86%, with a rate constant of 0.01494 min −1 , surpassing that of pristine CuWO 4 . This improvement in performance is largely due to Ag's role in promoting the formation of reactive oxygen species (ROS). Additionally, PL measurements confirmed that Ag incorporation effectively enhances charge-carrier separation in the Ag-CuWO 4 structure, thereby suppressing recombination losses. Radical scavenging experiments further identified electrons and hydroxyl radicals as the dominant reactive species involved in the oxidative degradation of the CV dye. The study also systematically explored the impacts of operational parameters, including solution pH, dye concentration, and catalyst amount, on photocatalytic performance. Overall, Ag-doped CuWO 4 demonstrates enhanced photocatalytic activity for dye degradation, indicating its potential for further investigation in wastewater treatment applications.