Dual electron transfer path and Ti3C2Tx LSPR photothermal enhancement in 2D/2D/2D Ti3C2Tx MXene@TiO2/CdIn2S4 ternary heterojunction for enhanced photocatalytic H2 production: Construction, kinetics, and mechanistic insights

Abstract

It is an inherent problem in the field of photocatalytic hydrogen (H2) production to realize the effective coordination and mutual promotion between multi-component materials. In this work, using the monolayer plasmonic Ti3C2Tx as substrate, the first example of a 2D/2D/2D Ti3C2Tx MXene@TiO2/CdIn2S4 (MTC) ternary heterojunction nanocomposite containing O and S dual vacancies is synthesized. Dual high density electron transfer path and Ti3C2Tx LSPR photothermal effect synergistically enhance light absorption, photogenerated charge carrier separation, and surface reaction rates. At room temperature, the photocatalytic H2 production rate of MTC50 reaches 6762.1 μmol·g−1·h−1. Through DFT and FDTD methods, it is proved that high density electron transfer and large area strong plasmon coupling effectively enhance the photothermal effect of Ti3C2Tx LSPR, which provides reasonable inspiration for the design of photocatalysts in extremely cold environment. This work provides important insights into the construction of 2D multi-component systems and the explanation of the LSPR enhancement mechanism.