Harnessing sunlight: unlocking superior photocatalytic activity of g-C₃N₄/MnWO₄ heterojunction photocatalysts for degradation of hazardous compounds

A facile heat fusion spreading technique has been developed to fabricate two-dimensional (2D)/3D g-C₃N₄/MnWO₄ (g-CN/MW) heterojunction photocatalysts. Concurrent exfoliation and deposition of g-C₃N₄ on the surface of MW are achieved in a single-step process. Adjusting the carbon nitride loadings in this technique enables controlled coating of carbon nitride onto the rough surfaces of manganese tungstate particles. The xg-CN/MW catalysts demonstrate excellent photocatalytic decomposition of Clioquinol (drug) and Chlorpyriphos (insecticide) under sunlight. The degradation performance is highly dependent on the carbon nitride loading and reaches a maximum at 12 wt.%. Carbon nitride loadings lower and higher than 12 wt.% resulted in inferior performance. Scavenger studies revealed that holes play a key role, and a plausible S-Scheme mechanism has been proposed. The 12% g-CN/MW sample shows good recycling abilities with 85% and 83% conversions after the 5th run towards Clioquinol and Chlorpyriphos, respectively, indicating their potential towards practical applications.