Improving hydrogen evolution reaction performance by combining ditungsten carbide and nitrogen-doped graphene: A first-principles study

Exploring electrocatalysts with high performance for the hydrogen evolution reaction (HER) is critical to the development of clean hydrogen energy, and their composition/structures are essential for this function. For the purpose of this study we proposed a variety of heterostructural models combining W2C and graphene-like (G-like) models, especially N-doped G-like models (GN, P3N and P2V4N), and evaluated their catalytic activities using DFT. Compared with the single component (G, GN, P3N, P2V4N or pure W2C), these heterogeneous models showed comparable or higher HER performance. Furthermore, the pH effects on ΔGH of all proposed models have also been investigated. The results revealed that the heterostructural models composed of N-modified G-like models and W2C have catalytically active sites with ΔGH = 0 eV, no matter in acidic, neutral or alkaline environments, which indicates that the N-doping enables them to maintain high catalytic activity in a wider pH range. It is expected that our calculation results could provide theoretical basis for the design and synthesis of catalysts with high HER performance.