Revealing the Superior Electrocatalytic Performance of 2D Monolayer WSe2 Transition Metal Dichalcogenide for Efficient H2 Evolution Reaction

Abstract

AbstractH2 evolution reaction (HER) requires an electrocatalyst to reduce the reaction barriers for the efficient production of H2. 2D transition metal dichalcogenides (2D TMDs) have emerged as a pinnacle group of materials for many potential applications, including HER. In this work, a pristine 2D monolayer WSe2 TMD is computationally designed using the first principle‐based hybrid density functional theory (DFT) to investigate its structural, electronic properties and the electrocatalytic performance for HER. The possible Volmer‐Heyrovsky and Volmer‐Tafel reaction mechanisms for HER at the W‐edge of the active site of WSe2 are studied by using a nonperiodic finite molecular cluster model W10Se21. The study shows that the pristine 2D monolayer WSe2 follows either the Volmer‐Heyrovsky or the Volmer‐Tafel reaction mechanisms with a single‐digit low reaction barrier about 6.11, 8.41 and 6.61 kcal mol−1 during the solvent phase calculations of H•‐migration, Heyrovsky and Tafel transition (TS) states, respectively. The lower reaction barriers, high turnover frequency (TOF) ≈ 4.24 × 106 s−1 and 8.86 × 107 s−1 during the Heyrovsky and Tafel reaction steps and the low Tafel slope 29.58 mV dec−1 confirm that the pristine 2D monolayer WSe2 might be a promising alternative to platinum group metals (PGM) based electrocatalyst.