A First Principles exploration of pristine and p-block doped triangulene carbon dots for Hydrogen evolution reaction

Abstract

The global pursuit of clean and sustainable energy sources has driven significant research into the hydrogen evolution reaction (HER). In this process, we need catalysts that outperform noble metals, and Triangulene carbon dots (TCDs) are prospective suitors. Therefore, in this study, we explore the potential of pristine and p-block element-doped TCDs as alternative electrocatalysts for HER. Stability is one of the most important virtues for a material to be a good catalyst. We have investigated the cohesive energy and formation energy of doped TCDs, and we observed that N-doped and B-doped TCDs are the most favorable energetically. We observed a lowering of the energy gap with doping, except for Si, leading to an increase in conductivity, which is expected to result in better HER activity. The increased conductivity leads to higher charge transfer between the H atom and TCDs, as validated through Mulliken charge plots. To confirm the enhanced HER activity, we computed the Gibbs free energies, and N-doped TCDs outperformed pristine TCD and B-doped TCD in HER activity, followed by the others, also corroborated by the volcano plot.