Taking advantage of the self-assembling function of amino acids, cobaltalanine complexes are synthesized by straightforward process of chemical precipitation. Through a controllable calcination of the cobalt-alanine complexes, N-doped Co 3 O 4 nanostructures (N-Co 3 O 4 ) and N-doped CoO composites with amorphous carbon (N-CoO/C) are obtained. These N-doped cobalt oxide materials with novel porous nanostructures and minimal oxygen vacancies show a high and stable activity for the oxygen evolution reaction. Moreover, the influence of calcination temperature, electrolyte concentration, and electrode substrate to the reaction are compared and analyzed. The results of experiments and density functional theory calculations demonstrate that N-doping promotes the catalytic activity through improving electronic conductivity, increasing OH − adsorption strength, and accelerating reaction kinetics. Using a simple synthetic strategy, N-Co 3 O 4 reserves the structural advantages of micro/nanostructured complexes, showing exciting potential as a catalyst for the oxygen evolution reaction with good stability.

As representative two-dimensional (2D) materials, layered double hydroxides (LDHs) have received increasing attention in electrochemical energy storage and conversion because of the facile tunability between their composition and morphology. The high dispersion of active species in layered arrays, the simple exfoliation into monolayer nanosheets and chemical modification offer the LDHs an opportunity as active electrode materials in electrochemical capacitors (ECs). LDHs are favourable in providing large specific surface areas, good transport features as well as attractive physicochemical properties. In this review, our purpose is to provide a detailed summary of recent developments in the synthesis and electrochemical performance of the LDHs. Their composites with carbon (carbon quantum dots, carbon black, carbon nanotubes/nanofibers, graphene/graphene oxides), metals (nickel, platinum, silver), metal oxides (TiO, CoO, CuO, MnO, FeO), metal sulfides/phosphides (CoS, NiCoS, NiP), MOFs (MOF derivatives) and polymers (PEDOT:PSS, PPy (polypyrrole), P(NIPAM-co-SPMA) and PET) are also discussed in this review. The relationship between structures and electrochemical properties as well as the associated charge-storage mechanisms is discussed. Moreover, challenges and prospects of the LDHs for high-performance ECs are presented. This review sheds light on the sustainable development of ECs with LDH based electrode materials.

Electrocatalysis of the hydrogen evolution reaction (HER) is a vital and demanding, yet challenging, task to produce clean energy applications. Here, the RuRh2 bimetallene nanoring with rich structural defects is designed and successfully synthesized by a mixed‐solvent strategy, displaying ascendant HER performance with high mass activity at −0.05 and −0.07 V, separately higher than that of the commercial Pt catalyst. Also, it maintains steady hydrogen bubble evolution even after 30 000 potential cycles in acid media. Furthermore, the RuRh2 bimetallene nanoring shows an outstanding activity in both alkaline and neutral media, outperforming that of Pt catalysts and other reported HER catalysts. A combination of atomic‐scale structure observation and density functional theory calculations demonstrates that both the grain boundaries and symmetry breaking of RuRh2 bimetallene cannot only weaken the adsorption strength of atomic hydrogen, but also facilitate the transfer of electrons and the adsorption of reactants, further boosting the HER electrocatalytic performance in all pH values.

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The single-atomic-site doping of oxophilic-metal (Ru) species in FeCo-LDH leads to the active atom reconstruction at symmetry-breaking interfaces and then the excellent catalytic performance for OER/HER and overall water splitting at large current densities.