2D/2D Heterojunction of R-scheme Ti3C2 MXene/MoS2 Nanosheets for Enhanced Photocatalytic Performance

Combination of two-dimensional (2D) materials and semiconductors is considered to be an effective way for fabricating photocatalysts for solving the environmental pollution and energy crisis. In this work, novel 2D/2D heterojunction of R-scheme Ti3C2 MXene/MoS2 nanosheets is successfully synthesized by hydrothermal reaction. The photocatalytic activity of the Ti3C2 MXene/MoS2 composites is evaluated by photocatalytic degradation and hydrogen evolution reaction. Especially, 0.5 wt% Ti3C2 MXene/MoS2 sample exhibits optimum methyl orange (MO) degradation and H2 evolution rate of 97.4% and H2 evolution rate of 380.2 μmol h-1 g-1, respectively, which is attributed to the enhanced optical absorption ability and increased specific surface area. Additionally, Ti3C2 MXene coupled with MoS2 nanosheets is favorable for improving the photocurrent response and reducing the electrochemical impedance, leading to the enhanced electron transfer of excited semiconductor and inhibition of charge recombination. This work demonstrates that Ti3C2 MXene could be a promising carrier to construct 2D/2D heterojunction in photocatalytic degradation and hydrogen evolution reaction.