Plasmonic Au Nanoparticle@Ti₃C₂T_x Heterostructures for Improved Oxygen Evolution Performance

As we know, in plasmonic-enhanced heterogeneous catalysis, the reaction rates could be remarkably accelerated by generating hot carriers in the constituent nanostructured metals. To further improve the reaction rate, well-defined heterostructures based on plasmonic gold nanoparticles on MXene Ti₃C₂T_x nanosheets (Au NPs@Ti₃C₂T_x) were rationally designed and systematically investigated to improve the performance of the oxygen evolution reaction (OER). The results demonstrated that the catalysis performance of the Au NPs@Ti₃C₂T_x system could be easily tuned by simply varying the concentration and size of Au NPs, and Au NPs@Ti₃C₂T_x with an average Au NP diameter (∼10 nm) exhibited a 2.5-fold increase in the oxidation or reduction current compared with pure Ti₃C₂T_x. The enhanced OER performance can be attributed to the synergistic effect of the plasmonic hot hole injection and Schottky junction carrier trapping. Owing to easy fabrication of Au NPs@Ti₃C₂T_x, the tunable size and concentration of Au NPs loaded on MXene nanosheets, and the significantly enhanced OER, it is expected that this work can lay the foundation to the design of multidimensional MXene-based heterostructures for highly efficient OER performance.