Vapor-Assisted In Situ Synthesis of the Nb₂CT<i>_x</i>NS/NbO₂F MXene Heterostructure for Enhanced Solar-Driven Photoelectrochemical Performance

Photocatalytic water splitting holds great potential for transforming solar energy into valuable chemical products. However, obstacles such as the rapid recombination of electron-hole pairs and insufficiently active surface areas of photocatalysts remain significant challenges. In this study, we present the first demonstration that lithium bis(trifluoromethanesulfonyl)imide vapor successfully etches aluminum from Nb₂AlC MAX phase powders while concurrently forming NbO₂F anchors on Nb₂CT<i>_x</i> nanosheet (Nb₂CT<i>_x</i>NS) MXene, leading to the in situ formation of a Nb₂CT<i>_x</i>NS/NbO₂F heterostructure composite. This novel material exhibits a remarkable photoelectrochemical performance, achieving a current density of 252 μA cm^-2, which is 1000 and 10 times greater than those of Nb₂AlC MAX and Nb₂C nanosheet MXene, respectively. These findings shed light on innovative approaches for developing photocatalytic materials via vapor-assisted synthesis, offering a promising pathway for advancing material discovery in both photo- and energy-related fields.