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

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 (Nb2O5/C/Nb2C) as photocatalysts for hydrogen evolution from water splitting. The Nb2O5/C/Nb2C composites were synthesized by one‐step CO2 oxidation of Nb2CTx. Nb2O5 grew homogeneously on Nb2C after mild oxidation, during which some amorphous carbon was also formed. With an optimized oxidation time of 1.0 h, Nb2O5/C/Nb2C showed the highest hydrogen generation rate (7.81 μmol h−1 gcat−1), a value that was four times higher than that of pure Nb2O5. The enhanced performance of Nb2O5/C/Nb2C was attributed to intimate contact between Nb2O5 and conductive Nb2C and the separation of photogenerated charge carriers at the Nb2O5/Nb2C interface; the results presented herein show that transition‐metal carbide are promising co‐catalysts for photocatalytic hydrogen production. Shedding light on carbides: Niobium pentoxide/carbon/niobium carbide hybrid materials (Nb2O5/C/Nb2C) are prepared as photocatalysts for hydrogen evolution. The Nb2O5/C/Nb2C sample with an oxidation time of 1.0 h shows a hydrogen generation rate that is four times higher than that of pure Nb2O5. The enhanced performance is attributed to the separation of photogenerated carriers and the formation of a Schottky junction.