New Efficient Electrocatalyst for the Hydrogen Evolution Reaction: Erecting a V2Se9@Poly(3,4-ethylenedioxythiophene) Nanosheet Array with a Specific Active Facet Exposed

To obtain catalysts with remarkable activity for the hydrogen evolution reaction (HER), rational design and synthesis of catalysts with rich active sites are very urgent. Herein, we reported, for the first time, V2Se9 nanosheet arrays exposed with the highly active (100) facet as a new efficient catalyst for HER. The highly active but thermodynamically instable (100) facet was converted from V2O5 based on a low crystal-mismatch strategy. Furthermore, conductive poly(3,4-ethylenedioxythiophene) (PEDOT) acting as a co-catalyst further contributed to the redistribution of charge and reduction of hydrogen adsorption energy. Due to the strong synergistic effect between V2Se9 and PEDOT, the resulting material, noted as V2Se9@PEDOT NSs/NF, exhibited excellent electrocatalytic performance among selenide catalysts, for example, a small overpotential of 72 mV at 10 mA cm–2, a low Tafel slope of 36.5 mV dec–1, and remarkable durability. Simultaneously, density functional theory (DFT) computations proved that the ads...