Realizing the regulated carrier separation and exciton generation of Bi₂₄O₃₁Cl₁₀: Via a carbon doping strategy

The insufficient efficiency of carrier separation and faint exciton generation are the major limitations of photocatalytic performance. We herein report a dual-purpose strategy for enabling the carrier separation and exciton production of Bi₂₄O₃₁Cl₁₀via carbon doping. An impurity state appears after carbon doping in Bi₂₄O₃₁Cl₁₀, which can furnish the charge transport channels and promote carrier separation. DFT calculations confirm that a more localized distribution of conduction and valence band charges strengthens the electron-hole interaction, significantly boosting exciton generation. Besides, the hierarchical structure endows carbon-doped Bi₂₄O₃₁Cl₁₀ with a higher specific surface area. As a consequence, the photoreactivity towards photocatalytic CO₂ reduction and singlet oxygen (¹O₂) generation is dramatically enhanced in carbon-doped Bi₂₄O₃₁Cl₁₀. This study develops an effective pathway to manipulate the behavior of photoexcited species, which allows for the optimum design of excellent photocatalysts with emergent properties in energy conversion and environmental remediation.