Tuning the Electronic Structure of Se via Constructing Rh-MoSe₂ Nanocomposite to Generate High-Performance Electrocatalysis for Hydrogen Evolution Reaction

As one of the most promising acid-stable catalysts for hydrogen evolution reaction (HER), MoSe₂ was hampered by the limited quantity of active sites and poor conductivity, which severely impede the efficiency of hydrogen production. Different from heteroatoms doping and conductivity improvement, to address this issues, the electronic structure of active edge sites Se in MoSe₂ were modulated by electron injection from ruthenium deposited on MoSe₂ nanosheets. The Rh-MoSe₂ nanocomposite exhibits great performance enhancement with a low onset potential of 3 mV and quite low overpotential of 31 mV (vs RHE), which is superior to almost all Rh-based and MoSe₂-based electrocatalysts. Experimental results and density functional theory (DFT) simulations reveal that the performance improvement stems from the modulated electronic structure of Se atoms at the edge sites by electron transfer from metal Rh to MoSe₂ support, which leads to a moderate Δ<i>G</i>_H* value of 0.09 eV compared to 0.83 eV for MoSe₂ and −0.26 eV for Rh