Perovskite CsPbI3 Nanocrystal and Nanowire Incorporated G-C3N4 Nanosheets for CO2 Reduction and NO Removal.

Expanded light absorption and optimized heterostructure interfaces can significantly enhance photocatalytic redox performance. Herein, perovskite CsPbI3 nanocrystals (NCs) and nanowires (NWs) are integrated with graphitic carbon nitride (g-C3N4) nanosheets via a combined mechano-chemical pre-reaction and solvothermal process. This strategy effectively removes surface ligands and enables the formation of well-defined heterostructures with strong interfacial contact, facilitating efficient charge carrier transfer. The distinct morphologies and band structures of CsPbI3 NCs and NWs lead to differentiated photocatalytic behaviors in CO2 reduction and NO removal. An S-scheme charge transfer mechanism further promotes charge separation and migration. Among the composites, g-C3N4/CsPbI3 NWs exhibit superior CO2 reduction activity, achieving a visible-light-driven CO production rate of 4.6 µmol g-1 h-1, attributed to the face-to-face interface and one-dimensional architecture that enhance charge transport. In contrast, g-C3N4/CsPbI3 NCs demonstrate excellent NO removal performance, with a removal efficiency of 69.5% and low NO2 selectivity (5.0%) at 600 ppb NO, owing to the generation of high-energy photoinduced charge carriers. This work presents a versatile design strategy for g-C3N4-based photocatalysts toward efficient energy conversion and environmental remediation.