Simultaneous realization of improved activity, enhanced stability, and reduced cost remains a desirable yet challenging goal in the search of electrocatalysis oxygen evolution reaction (OER) in acid. Herein, we report a novel strategy to prepare iridium single-atoms (Ir-SAs) on ultrathin NiCo2O4 porous nanosheets (Ir–NiCo2O4 NSs) by the co-electrodeposition method. The surface-exposed Ir-SAs couplings with oxygen vacancies (VO) exhibit boosting the catalysts OER activity and stability in acid media. They display superior OER performance with an ultralow overpotential of 240 mV at j = 10 mA cm–2 and long-term stability of 70 h in acid media. The TOFs of 1.13 and 6.70 s–1 at an overpotential of 300 and 370 mV also confirm their remarkable performance. Density functional theory (DFT) calculations reveal that the prominent OER performance arises from the surface electronic exchange-and-transfer activities contributed by atomic Ir incorporation on the intrinsic VO existed NiCo2O4 surface. The atomic Ir sites substantially elevate the electronic activity of surface lower coordinated Co sites nearby VO, which facilitate the surface electronic exchange-and-transfer capabilities. With this trend, the preferred H2O activation and stabilized *O have been reached toward competitively lower overpotential. This is a generalized key for optimally boosting OER performance.

Involving eight electron transfer process and multiple intermediates of nitrate (NO3−) reduction reaction leads to a sluggish kinetic and low Faradaic efficiency, therefore, it is essential to get an insight into the reaction mechanism to develop highly efficient electrocatalyst. Herein, a series of reduced‐graphene‐oxide‐supported RuCu alloy catalysts (RuxCux/rGO) are fabricated and used for the direct reduction of NO3− to NH3. It is found that the Ru1Cu10/rGO shows the ammonia formation rate of 0.38 mmol cm−2 h−1 (loading 1 mg cm−2) and the ammonia Faradaic efficiency of 98% under an ultralow potential of −0.05 V versus Reversible Hydrogen Electode (RHE), which is comparable to Ru catalyst. The highly efficient activity of Ru1Cu10/rGO can be attributed to the synergetic effect between Ru and Cu sites via a relay catalysis, in which the Cu shows the exclusively efficient activity for the reduction of NO3− to NO2− and Ru exhibits the superior activity for NO2− to NH3. In addition, the doping of Ru into Cu tunes the d‐band center of alloy and effectively modulates the adsorption energy of the NO3− and NO2−, which promotes the direct reduction of NO3− to NH3. This synergetic electrocatalysis strategy opens a new avenue for developing highly efficient multifunctional catalysts.

We report a novel modulation strategy by introducing transition metals into NiS2 nanosheets (NSs) to flexibly optimize the electronic configurations and atomic arrangement. The Co‐NiS2 NSs exhibit excellent hydrogen evolution reaction (HER) performance with an overpotential of 80 mV at j=10 mA cm−2 and long‐term stability of 90 h in alkaline media. The turnover frequencies (TOFs) of 0.55 and 4.1 s−1 at an overpotential of 100 and 200 mV also confirm their remarkable performance. DFT calculations reveal that the surface dopants abnormally sensitize surface Ni‐3d bands in the long‐range order towards higher electron‐transfer activity, acting as the electron‐depletion center. Meanwhile, the high lying surface S‐sites possess substantially high selectivity for splitting the adsorbing H2O that guarantee the high HER performance within alkaline conditions. This work opens opportunities for enhancing water splitting by atomic‐arrangement‐assisted electronic modulation via a facile doping strategy.

Li-rich layered oxides have been in focus because of their high specific capacity. However, they usually suffer from poor kinetics, severe voltage decay, and capacity fading. Herein, a long-neglected Li-deficient method is demonstrated to address these problems by simply reducing the lithium content. Appropriate lithium vacancies can improve dynamics features and induce in situ surface spinel coating and nickel doping in the bulk. Therefore, the elaborately designed Li 1.098 Mn 0.533 Ni 0.113 Co 0.138 O 2 cathode possesses improved initial Coulombic efficiency, excellent rate capability, largely suppressed voltage decay, and outstanding long-term cycling stability. Specifically, it shows a superior capacity retention of 93.1% after 500 cycles at 1 C (250 mA g −1 ) with respect to the initial discharge capacity (193.9 mA h g −1 ), and the average voltage still exceeds 3.1 V. In addition, the discharge capacity at 10 C can be as high as 132.9 mA h g −1 . More importantly, a Li-deficient cathode can also serve as a prototype for further performance enhancement, as there are plenty of vacancies.

evolution and oxygen reduction reaction (OER and ORR) performance of the air cathode limits the efficiency of Zn-air batteries owing to the sluggish kinetics and multistep proton-coupled electron transfer process on the catalyst surface. [4-6] Anode passivation typically reduces the performance of Zn-air batteries in hard alkaline electrolytes. Moreover, aqueous electrolytes limit the temperature range of the Zn-air battery applications. [7,8] Several strategies, such as the preparation of superior catalysts with remarkable OER and ORR activity and excellent stability, [9-12] the design of new Zn-air battery systems in facile media (such as natural conditions), [13-15] and tailoring the electrolyte properties to achieve a wide temperature range for Zn-air battery applications, [7,8,16-18] have been developed to address these problems and enhance the performance of Zn-air batteries. Although many efforts have been dedicated to increasing the use of Zn-air battery in different fields, the current performance of the Zn-air batteries is still unsatisfactory utilizations in many fields, particularly under low temperature condition. The performance of Zn-air batteries depends on the bifunctional catalytic activity of the air-cathode electrode. Typically, noble Herein, a strategy is reported for the fabrication of NiCo 2 O 4-based mesoporous nanosheets (PNSs) with tunable cobalt valence states and oxygen vacancies. The optimized NiCo 2.148 O 4 PNSs with an average Co valence state of 2.3 and uniform 4 nm nanopores present excellent catalytic performance with an ultralow overpotential of 190 mV at a current density of 10 mA cm −2 and long-term stability (700 h) for the oxygen evolution reaction (OER) in alkaline media. Furthermore, Zn-air batteries built using the NiCo 2.148 O 4 PNSs present a high power and energy density of 83 mW cm −2 and 910 Wh kg −1 , respectively. Moreover, a portable battery box with NiCo 2.148 O 4 PNSs as the air cathode presents long-term stability for 120 h under low temperatures in the range of 0 to −35 °C. Density functional theory calculations reveal that the prominent electron exchange and transfer activity of the electrocatalyst is attributed to the surface lower-coordinated Co-sites in the porous region presenting a merging 3d-e g-t 2g band, which overlaps with the Fermi level of the Zn-air battery system. This favors the adsorption of the *OH, and stabilized *O radicals are reached, toward competitively lower overpotential, demonstrating a generalized key for optimally boosting overall OER performance. Zn-air batteries, as a promising alternative to fossil fuel, have received much attention owing to their safety, cleanliness, and efficiency. [1-3] However, Zn-air batteries still present shortcomings for large-scale applications, as follows. The oxygen The ORCID identification number(s) for the author(s) of this article can be found under