Nitrogen coordinated metal single atoms in carbon have aroused extensive interest recently and have been growing as the active research frontier in a wide range of key renewable energy reactions and devices. However, single-atom catalysts with isolated metallic active components cannot satisfy the demand of electrocatalysis with the requirement in selectivity. Herein, we develop a step-by-step self-assembly strategy to allocate nickel (Ni) and iron (Fe) single atoms respectively on the inner and outer walls of graphene hollow nanospheres (GHSs), for the first time realizing the separate-sided different single-atom functionalization of hollow graphene. The Ni or Fe single atom is demonstrated to be coordinated with four N atoms via the formation of a Ni-N 4 or Fe-N 4 planar experimental observations. As a proof-of-concept demonstration for realistic application, the Ni-N 4 /GHSs/Fe-N 4 endows the rechargeable Zn-air battery with excellent energy efficiency and cycling stability as an air-cathode, outperforming the performance of benchmark Pt/C+RuO 2 air-cathode. The current work paves a new avenue for precise control of single-atom sites on carbon surface for the high-performance and selective electrocatalysts.

Tailoring composition and morphology of electrocatalysts is of great importance in improving their catalytic performance. Herein, a salt‐templated strategy is proposed to construct novel multicomponent Co/CoxMy (M = P, N) hybrids with outstanding electrocatalytic performance for the oxygen evolution reaction (OER). The obtained Co/CoxMy hybrids present porous sheet‐like architecture consisting of many hierarchical secondary building‐units. The synthetic strategy depends on a facile and effective dissolution–recrystallization–pyrolysis process under NH3 atmosphere of the precursors, which does not involve any surfactant or long‐time hydrothermal pretreatment. That is different from the conventional methods for the synthesis of hierarchical nitrides/phosphides. Benefitting from unique composition/structure‐dependent merits, the Co/CoxMy hybrids as a typical Mott–Schottky electrocatalyst exhibit good OER performance in an alkaline medium compared with their counterparts, as evidenced by a low overpotential of 334 mV at 10 mA cm−2 and a small Tafel slope of 79.2 mV dec−1, as well as superior long‐term stability. More importantly, the Co/CoxMy+Pt/C achieves higher voltaic efficiency and several times longer cycle life than conventional RuO2+Pt/C catalysts in rechargeable Zn–air batteries. It is envisioned that the present work can provide a new avenue for the development of Mott–Schottky electrocatalysts for sustainable energy storage.

Efficient water splitting through electrocatalysis has been studied extensively in modern energy devices, whereas the development of catalysts with high activity and stability with low‐load Pt is still a great challenge. Through the spatial confinement effect and template method, herein, hollow graphene spheres with functionalized Pt nanoclusters (Pt/GHSs) are constructed and developed as effective electrocatalysts for the hydrogen evolution reaction (HER). Electrochemical tests show that Pt/GHSs exhibit a high electrocatalytic activity and stability compared with commercial Pt/C catalysts toward HER in alkaline media. The electric double‐layer capacitance value reaches 26.0 mF cm−2, indicating that Pt/GHSs have a large electrochemically active area. Meanwhile, the load of metal Pt in the Pt/GHSs is only one‐fifth of commercial Pt/C catalysts, which significantly reduces the production cost of the catalyst. Herein a new opportunity for the low‐cost mass production of efficient and stable catalysts for practical applications is provided.

Ammonia (NH3) is an important chemical for human beings; however, the majority of NH3 is produced by the energy-intensive and environmentally unfriendly Haber–Bosch process. Electrocatalytic N2 reduction reaction (NRR) under...

Minimizing the particle size of transition metals and constructing heteroatom-co-doped carbon with a high surface area are deemed imperative in maximizing the atomic utilization of carbon-based materials. Herein, the atomically dispersed Co sites anchored on interconnected B, N-doped carbon nanotubes (B, N, Co/C nanotubes) are prepared through facile molten-salt-assisted pyrolysis of B/N/Co precursors following chemical etching. The Co single atom is demonstrated to form a Co–N4 planar configuration by XAFS analysis. The developed B, N, Co/C nanotubes exhibit excellent oxygen reduction reaction (ORR) performance in alkaline medium. They not only display a positive half-wave potential (E 1/2, 0.87 V), surpassing that of commercial Pt/C (0.84 V), but also show an outstanding stability (only 1 mV degrade can be observed after 10,000 cycles) and a high fuel selectivity. These excellent ORR performances derive from the efficient synergy of atomically dispersed Co active sites, unique 3D tubelike assembly structure, large specific surface area, and high graphitization degree. Moreover, the B, N, Co/C nanotubes assisted by RuO2 as an air cathode can enable rechargeable Zn–air batteries with larger power density (125.0 mW cm–2), higher specific capacity (746.8 mA h gZn –1), and better cycling stability than those of conventional Pt/C + RuO2-based Zn–air batteries.