Recent developments in transition metal carbides and nitrides as hydrogen evolution electrocatalysts.

The production of hydrogen by the electrolysis of water, a sustainable and greenhouse-gas-free source, requires an efficient and abundant electrocatalyst that minimizes energy consumption. Interest in transition metal carbides and nitrides has been aroused by their promising properties that make them potential substitutes for Pt-group metals as catalysts for the hydrogen evolution reaction. In this review, we discuss systematically the recent progress in the development of group IV-VI metal carbides and nitrides toward the hydrogen evolution reaction. Some strategies for designing such catalysts and improving their efficiency and reliability, including nanostructuring, optimizing hydrogen binding energy, interaction with the supporting material, and exploiting hybrid structures, are highlighted. We conclude with an outlook on the challenges in designing future HER electrocatalysts.