Boosting the electrocatalytic performance of the single Fe/Co atom anchored on pristine and B/N doped 8-16-4 graphyne for overall water splitting

Abstract

Highly efficient electrocatalysts supporting the hydrogen evolution reaction (HER) and oxygen evolution reac- tion (OER) are crucial for developing the next generation of clean and sustainable energy systems. As a two- dimensional carbon allotrope, 8-16-4 graphyne (GY) provides an excellent platform for anchoring single-atom catalysts (SAC) thanks to its unique surface and electronic characteristics. The local electronic environment on the GY surface is significantly influenced by external atom doping, leading to an enhancement in the catalytic performance. In this work, using DFT computations, we fine-tune the position and number of N and B dopants, both individually and in combination, in the framework of SACs supported on the GY (Co-GY and Fe-GY). We comprehensively evaluated stability, electronic structure, and electrocatalytic performance of the proposed catalysts for both HER and OER. The outcomes of our study reveal that the bifunctional electrocatalytic per- formance of Fe–B2-GY and Co–2N2-GY is significantly improved compared to Fe-GY and Co-GY, and they are the best bifunctional electrocatalysts for overall water splitting reaction with OER/HER overpotentials of 1.18/–0.07 eV (Fe–B2-GY) and 0.57/0.03 eV (Co–2N2-GY). This investigation helps researchers fine-tune the electronic structures of catalysts and enhance catalytic efficiency.