2D/2D heterojunction of Ti 3 C 2 /g-C 3 N 4 nanosheets for enhanced photocatalytic hydrogen evolution

• Published in: Nanoscale Vol. 11; no. 17; pp. 8138 - 8149
• Main Authors: Su, Tongming, Hood, Zachary D., Naguib, Michael, Bai, Lei, Luo, Si, Rouleau, Christopher M., Ivanov, Ilia N., Ji, Hongbing, Qin, Zuzeng, Wu, Zili
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry (RSC) 25.04.2019
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/C9NR00168A

Photocatalytic hydrogen evolution from water has received enormous attention due to its ability to address a number of global environmental and energy-related issues. Here, we synthesize 2D/2D Ti 3 C 2 /g-C 3 N 4 composites by electrostatic self-assembly technique and demonstrate their use as photocatalysts for hydrogen evolution under visible light irradiation. The optimized Ti 3 C 2 /g-C 3 N 4 composite exhibited a 10 times higher photocatalytic hydrogen evolution performance (72.3 μmol h −1 g cat −1 ) than that of pristine g-C 3 N 4 (7.1 μmol h −1 g cat −1 ). Such enhanced photocatalytic performance was due to the formation of 2D/2D heterojunctions in the Ti 3 C 2 /g-C 3 N 4 composites. The intimate contact between the monolayer Ti 3 C 2 and g-C 3 N 4 nanosheets promotes the separation of photogenerated charge carriers at the Ti 3 C 2 /g-C 3 N 4 interface. Furthermore, the ultrahigh conductivity of Ti 3 C 2 and the Schottky junction formed between g-C 3 N 4 /MXene interfaces facilitate the photoinduced electron transfer and suppress the recombination with photogenerated holes. This work demonstrates that the 2D/2D Ti 3 C 2 /g-C 3 N 4 composites are promising photocatalysts thanks to the ultrathin MXenes as efficient co-catalysts for photocatalytic hydrogen production.