Optimizing oxygen functional groups on porous carbon monoliths by green activation promotes seawater hydrogen evolution†

Abstract

Oxygen-doped carbon materials are promising candidates for the electrocatalytic hydrogen evolution reaction (HER). However, optimizing and delineating the roles of specific oxygen-containing functional groups in modulating their catalytic activity remains challenging. Herein, a green and environmentally friendly method involving hydrogen peroxide (H₂O₂) hydrothermal activation of carbonized wood (CW) is employed to regulate and examine oxygen-containing functional groups. Experimental results show that oxygen-doped carbon with a higher proportion of CO species exhibits enhanced electrocatalytic activity in KOH and alkaline seawater. Theoretical calculations further revealed that the CO functional group regulated the electronic structure of defective carbon and improved the electrocatalytic activity of the HER by promoting the dissociation of water. This study presents a green method for modulating oxygen-containing functional groups and offers theoretical insights into their roles, paving the way for designing more efficient oxygen-doped, metal-free carbon-based electrocatalysts for HER.