Effects of activation method on biomass carbon-based materials used for electrochemical hydrogen evolution reaction catalyst

In recent years, the scarcity and high cost of platinum and other precious metals catalysts for hydrogen evolution in water electrolysis have stimulated the enthusiasm of researchers to study non-precious metals and carbon-based catalysts. Pure carbon materials themselves are inert to hydrogen evolution, but they have active catalytic sites after doping with heteroatoms, which has been verified by experiments and theoretical calculations. Biomass carbon materials with a wide range of sources and low cost have attracted more and more attention in the field of electrocatalytic hydrogen evolution catalysts due to their abundant heteroatomic doping. In order to improve the catalytic performance of biomass carbon-based catalysts, it is necessary to improve its specific surface area and promote the formation of specific structures by activation. In this review, the characteristics of physical activation, chemical activation and template activation are summarized. The activation mechanisms and applications of different types of activators such as KOH, KCl, ZnCl2 and H3PO4, arising in recent years, are analyzed in depth. Finally, the selection basis of activators is proposed, aiming to help researchers in the field of biomass carbon-based catalyst materials to scientifically select biomass precursors and activators.