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Surface/interface engineering plays an important role in improving the performance and economizing the cost and usage of electrocatalysts. In recent years, substantial progress has been achieved in designing and developing highly active electrocatalysts with the deepening understanding of surface and interface enhanced mechanism. In this review, recent development about optimizing the surface and interfacial structure in promoting the electrocatalytic activity of noble-metals and transition metal compounds is presented and the chemical enhancements are also described in detail. The relationship between the surface/interface structures (both atomic and electronic configuration) and the electrochemical behaviors has been discussed. Finally, personal perspectives have been proposed, highlighting the challenges and opportunities for future development in tuning the surface/interface active sites of electrocatalysts. We believe that this timely review will be beneficial to the construction of highly active and durable electrode materials through optimizing surface atomic arrangement and interfacial interaction, which can largely promote the development of next-generation clean energy conversion technologies.

A report is presented on the facile fabrication of Ni(SO4)0.3(OH)1.4 nanowires via the hydrothermal synthesis method. The outcome demonstrates that the existence of SO4 2− and a comparatively lower pH are of great essence to form nanowires morphology rather than flake-like or amorphous ones. When the molar ratio of SO4 2− to OH− was 1:1, almost pure nanowires of diameter 20−30 nm and several micrometres long could be obtained. Ni(SO4)0.3(OH)1.4 is actually a type of α-Ni(OH)2. The growth mechanism of this hydroxyl-lacking hydroxide is discussed. The embedded SO4 2− between Ni(OH)2 layers can realise electrostatic equilibrium which may ensure an hcp crystal structure of Ni(OH)2 having the trend to grow along the (001) direction. On the contrary, when SO4 2− was superseded by other anions, the nanowires would progressively convert to nanosheets, accompanied by an α-phase to β-phase transformation.