Carbon Dots Mediated In Situ Confined Growth of Bi Clusters on g-C3N4 Nanomeshes for Boosting Plasma-Assisted Photoreduction of CO2

Abstract

Synthesis of high-efficiency, cost-effective, and stable photocatalysts has long been a priority for sustainable photocatalytic CO₂ reduction reactions (CRR), given its importance in achieving carbon neutrality goals under the new development philosophy. Fundamentally, the sluggish interface charge transportation and poor selectivity of products remain a challenge in the CRR progress. Herein, this work unveils a synergistic effect between high-density monodispersed Bi/carbon dots (CDs) and ultrathin graphite phase carbon nitride (g-C₃N₄) nanomeshes for plasma-assisted photocatalytic CRR. The optimal g-C₃N₄/Bi/CDs heterojunction displays a high selectivity of 98% for CO production with a yield up to 22.7 µmol g⁻¹ without any sacrificial agent. The in situ confined growth of plasmonic Bi clusters favors the production of more hot carriers and improves the conductivity of g-C₃N₄. Meanwhile, a built-in electric field driving force modulates the directional injection photogenerated holes from plasmonic Bi clusters and g-C₃N₄ photosensitive units to adjacent CDs reservoirs, thus promoting the rapid separation and oriented transfer in the CRR process. This work sheds light on the mechanism of plasma-assisted photocatalytic CRR and provides a pathway for designing highly efficient plasma-involved photocatalysts.