▎ 摘　　要

Understanding the reactivity of boron and nitrogen codoped graphene (BNG) under the charged environment is essential in developing Pt-free counter electrode materials in the dye-sensitized solar cells (DSSCs). In this study, we have calculated the I-2 molecule adsorption and its dissociation on the negatively charged single-layer and multilayer BNG sheets to elucidate the charge effects on the BNG sheets' electrocatalytic activity. Compared with Pt, the multilayer BNG sheet can easily achieve the desorption of I* anions at low charge density and thereby further promotes the overall reaction rate of the I-3(-) reduction under dim light illumination. Also, our photovoltaic experiments of DSSCs with B and N codoped graphene quantum dots (BN-GQDs) support our computational results, which (BN-GQDs) support computational results, advances high-efficiency DSSCs under the ambient light environment (similar to 5000 lux).