The crucial role of strained ring in enhancing the hydrogen evolution catalytic activity for the 2D carbon allotropes: a high-throughput first-principles investigation

Abstract

Based on the density functional theory (DFT) calculations, we have firstly investigated the hydrogen evolution reaction (HER) catalytic activities for three kinds of two-dimensional (2D) carbon allotropes consisted of four-, six- and eight-membered rings, including net C, net W and net Y. Different from the inert graphene only consisted of six-membered rings, all these three carbon allotropes can exhibit the HER catalytic activity, with the net C superior to net W and net Y. It is revealed that the strain in four- or eight-membered ring with the antiaromaticity can play a crucial role in dominating their HER activities. Furthermore, the HER catalytic activities for all of three carbon allotropes can be effectively enhanced by doping N, B, O, P and S atoms with the different electronegativity, and the achievement of their high HER activities can be mainly due to the cooperation of foreign-atom doping with the ring strain effect. The correlative carbon atoms, shared by four-, six- and eight-membered rings, can uniformly serve as the most active site for all these 2D pure or doped carbon systems. Undoubtedly, introducing the correlative rings with the strain or antiaromaticity can be considered as the new and effective strategy to realize the highly efficient and nonprecious HER electrocatalysts, and all these intriguing findings obtained in this work can be advantageous for designing new kind of promising HER electrocatalysts.