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.

Ruthenium (Ru) has been theoretically considered a viable alkaline hydrogen evolution reaction electrocatalyst due to its fast water dissociation kinetics. However, its strong affinity to the adsorbed hydroxyl (OHad) blocks the active sites, resulting in unsatisfactory performance during the practical HER process. Here, we first reported a competitive adsorption strategy for the construction of SnO2 nanoparticles doped with Ru single‐atoms supported on carbon (Ru SAs‐SnO2/C) via atomic galvanic replacement. SnO2 was introduced to regulate the strong interaction between Ru and OHad by the competitive adsorption of OHad between Ru and SnO2, which alleviated the poisoning of Ru sites. As a consequence, the Ru SAs‐SnO2/C exhibited a low overpotential at 10 mA cm−2 (10 mV) and a low Tafel slope of 25 mV dec−1. This approach provides a new avenue to modulate the adsorption strength of active sites and intermediates, which paves the way for the development of highly active electrocatalysts.

Suffering from the competition adsorption between oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), the development of high‐efficiency oxygen electrocatalysts with bifunctional properties still remains a challenge. Herein, a novel and effective neodymium‐evoked valence electronic perturbation strategy to improve and balance reversible oxygen electrocatalysis of metallic cobalt sites is proposed. To heighten the coupling between Nd and Co, the metal‐organic‐framework‐induced method is chosen to prepare the target catalyst of atomic Nd‐doped Co on an N‐doped carbon substrate. The as‐prepared catalyst presents excellent bifunctional electrocatalytic properties with a low overpotential of 288 mV at 10 mA cm−2 for the OER and a high half‐wave potential of 0.85 V for the ORR. The robust electrocatalytic stabilities for both the ORR and OER are also proven. The electrochemical in situ Raman spectra confirm the surface dynamic change of the transformation of oxygen intermediates by noting the formation of Co–OOH. Theoretical calculations verify that the adsorption of oxygen intermediates is balanced owing to the strong Co 3d‐Nd 4f orbital electronic coupling effect below the Fermi level. Moreover, the potential practicability of catalyst is further demonstrated in solid‐state rechargeable Zn‐Air batteries, which exhibit large power density and a long cycling life.

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.