Tea biomass carbon quantum dots mediated Bi12O17Cl2 nanosheets for enhanced photocatalytic activities: Promoting the activation of molecular oxygen

In recent years, the development of catalysts with high spatial separation efficiency of photoinduced carriers and molecular oxygen activation has received extensive attention. In this research, a simple solvothermal method was employed to prepare Bi12O17Cl2 nanosheets modified with different concentrations of tea biomass carbon quantum dots (T-BCDs), and the morphology, structure and photo-electrochemical characteristics of the as- prepared catalysts were explored in detail. The tea biomass quantum dots adopted a green synthesis strategy. The method converts waste into high-value biomass carbon quantum dots, thereby enabling sustainable use of resources. T-BCDs can store and transfer photogenerated electrons, which can accelerate photoinduced carrier migration and charge separation, boost molecular oxygen activation, and enhance photocatalytic activities. Among which, Bi12O17Cl2 loading with 2 mL T-BCDs displays significantly enhanced photocatalytic performance towards the removal of antibiotics under visible and near-infrared light irradiation. In addition, microbial toxicological experiments show that the toxicity of the degradation products is significantly reduced. Superoxide radicals (center dot O2- ) and holes (h+) are determined to be the major reactive species in photocatalytic reactions. Finally, a viable photocatalytic mechanism is put forward. This study provides a promising strategy for the development of wide-spectrum responsive catalyst in the field of environmental purification.