Surface/interface engineering of high-efficiency noble metal-free electrocatalysts for energy-related electrochemical reactions

To date,much efforts have been devoted to the high-efficiency noble metal-free electrocatalysts for hydrogen-and oxygen-involving energy conversion reactions,due to their abundance,low cost and nultifunctionally.Surface/interface engineering is found to be effective in achieving novel physicochemical properties and synergistic effects in nanomaterials for electrocatalysis.Among various engineering strategies,heteroatom-doping has been regarded as a most promising method to improve the electrocatalytic performance via the regulation of electronic structure of catalysts,and numerous works were reported on the synthesis method and mechanism investigation of heteroatom-doping electrocatalysts,though the heteroatom-doping can only provide limited active sites.Engineering of other defects such as vacancies and edge sites and construction of heterostructure have shown to open up a potential avenue for the development of noble metal-free electrocatalysts.In addition,surface functionalization can attach various molecules onto the surface of materials to easily modify their physical or chemical properties,being as a promising complement or substitute for offering materials with catalytic properties.This paper gives the insights into the diverse strategies of surface/interface engineering of the highefficiency noble metal-free electrocatalysts for energy-related electrochemical reactions.The significant advances are summarized.The unique advantages and mechanisms for specific applications are highlighted.The current challenges and outlook of this growing field are also discussed.