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 multifunctionally. 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 high-efficiency noble metal-free electrocatalysts for energy-related electrochemical reactions. The significant advances are summarized. The unique advantages and mechanisms for specific applications are high-lighted. The current challenges and outlook of this growing field are also discussed. (C) 2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.