Two-dimensional V2O3 MOene as promising hydrogen evolution reaction electro-catalyst revealed by first-principles calculations

The single-layer dimetal oxides (MOenes) are recently predicted two-dimensional materials derived from the widely investigated MXenes. To develop high-performance hydrogen evolution reaction (HER) electro-catalysts that beyond oxygen-terminated MXenes, we theoretically proposed the oxygen-terminated V2O MOenes (2D V2O3) and explored their potential applications as HER electro-catalysts. Through the first-principles calculations, both the 1T and 2H phases of 2D V2O3 are confirmed to be structurally stable and electrically conductive. The simulations on catalytic performance and reaction mechanism on HER indicate that 2D V2O3 is highly active at a low hydrogen coverage of 18.75 %, with negligible activation barrier following the Volmer-Heyrovsky mechanism. When comparing with the Ti-based and V-based MXenes, the 2D V2O3 takes advantages in higher HER catalytic activity and stability of the surface termination. Moreover, the 2D V2O3 is expected to be experimentally obtained by exfoliation method.