One‐Step Synthesis of Nb2O5/C/Nb2C (MXene) Composites and Their Use as Photocatalysts for Hydrogen Evolution

Abstract Hydrogen production through facile photocatalytic water splitting is regarded as a promising strategy to solve global energy problems. Transition‐metal carbides (MXenes) have recently drawn attention as potential co‐catalyst candidates for photocatalysts. Here, we report niobium pentoxide/carbon/niobium carbide (MXene) hybrid materials (Nb 2 O 5 /C/Nb 2 C) as photocatalysts for hydrogen evolution from water splitting. The Nb 2 O 5 /C/Nb 2 C composites were synthesized by one‐step CO 2 oxidation of Nb 2 CT x . Nb 2 O 5 grew homogeneously on Nb 2 C after mild oxidation, during which some amorphous carbon was also formed. With an optimized oxidation time of 1.0 h, Nb 2 O 5 /C/Nb 2 C showed the highest hydrogen generation rate (7.81 μmol h −1 g cat −1 ), a value that was four times higher than that of pure Nb 2 O 5 . The enhanced performance of Nb 2 O 5 /C/Nb 2 C was attributed to intimate contact between Nb 2 O 5 and conductive Nb 2 C and the separation of photogenerated charge carriers at the Nb 2 O 5 /Nb 2 C interface; the results presented herein show that transition‐metal carbide are promising co‐catalysts for photocatalytic hydrogen production.