Wood-supported nitrogen-doped carbon quantum dot @Cu₂O composites for efficient photocatalytic degradation of dye wastewater

Photocatalytic degradation is a sustainable method for tackling various forms of environmental pollution. One challenge with this technology is the difficulty in recycling photocatalysts when they are in powdered form. To address this, wood, known for its porous structure and renewability, serves as an excellent substrate for photocatalysts. In this study, we developed a novel photocatalyst, W-NCQDs@Cu₂O, by impregnating nitrogen-doped carbon quantum dots (NCQDs) and Cu₂O composites onto carbonized wood via a straightforward hydrothermal synthesis method. This composite photocatalyst addresses the recycling challenges of powdered photocatalysts and features self-floating properties, which enhance its exposure to light and oxygen, thereby boosting photocatalytic efficiency. The effects of loading of NCQDs, solution pH, and cycling stability are carefully investigated. The optimal W-NCQDs@Cu₂O demonstrated a remarkable degradation rate of 96.4% at pH 6 within 120 min. Even after four cycles, the degradation performance robustly maintained at 78.9%, underscoring its substantial potential in wastewater treatment applications. The successful deployment of this composite material marks a significant stride towards practical wastewater treatment solutions, improving environmental quality and advancing sustainable development goals.