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.