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Constructing electrocatalysts with p‐block elements is generally considered rather challenging owing to their closed d shells. Here for the first time, we present a p‐block‐element bismuth‐based (Bi‐based) catalyst with the co‐existence of single‐atomic Bi sites coordinated with oxygen (O) and sulfur (S) atoms and Bi nanoclusters (Biclu) (collectively denoted as BiOSSA/Biclu) for the highly selective oxygen reduction reaction (ORR) into hydrogen peroxide (H2O2). As a result, BiOSSA/Biclu gives a high H2O2 selectivity of 95 % in rotating ring‐disk electrode, and a large current density of 36 mA cm−2 at 0.15 V vs. RHE, a considerable H2O2 yield of 11.5 mg cm−2 h−1 with high H2O2 Faraday efficiency of ∼90 % at 0.3 V vs. RHE and a long‐term durability of ∼22 h in H‐cell test. Interestingly, the experimental data on site poisoning and theoretical calculations both revealed that, for BiOSSA/Biclu, the catalytic active sites are on the Bi clusters, which are further activated by the atomically dispersed Bi coordinated with O and S atoms. This work demonstrates a new synergistic tandem strategy for advanced p‐block‐element Bi catalysts featuring atomic‐level catalytic sites, and the great potential of rational material design for constructing highly active electrocatalysts based on p‐block metals. [ABSTRACT FROM AUTHOR]

Cuprous oxide catalysts have attracted much attention because they exhibited high selectivity of C2+ products in CO2 electroreduction, but the effect of the structure of catalysts on the reaction needs to be studied further. Herein, we studied the effect of the coordination number (CN) of Cu–Cu and Cu–O in Cu2O on the catalytic performance of CO2 electrocatalytic reduction to C2H4. It was demonstrated that Cu–Cu CN and Cu–O CN, which could be tuned by changing the crystal surface and size of Cu2O, influenced the current density and faradaic efficiency (FE) of C2H4 significantly. At suitable CNs, the FE of C2H4 could reach 50.6% with a current density of 24.5 mA cm−2. [ABSTRACT FROM AUTHOR]

High-efficiency water electrolysis is the key to sustainable energy. Here we report a highly active and durable RuIrOx (x ≥ 0) nano-netcage catalyst formed during electrochemical testing by in-situ etching to remove amphoteric ZnO from RuIrZnOx hollow nanobox. The dispersing-etching-holing strategy endowed the porous nano-netcage with a high exposure of active sites as well as a three-dimensional accessibility for substrate molecules, thereby drastically boosting the electrochemical surface area (ECSA). The nano-netcage catalyst achieved not only ultralow overpotentials at 10 mA cm−2 for hydrogen evolution reaction (HER; 12 mV, pH = 0; 13 mV, pH = 14), but also high-performance overall water electrolysis over a broad pH range (0 ~ 14), with a potential of mere 1.45 V (pH = 0) or 1.47 V (pH = 14) at 10 mA cm−2. With this universal applicability of our electrocatalyst, a variety of readily available electrolytes (even including waste water and sea water) could potentially be directly used for hydrogen production. Water electrolysis is considered a key reaction for future sustainable fuel generation. Here, authors report a three-dimensional RuIrOx nano-netcage catalyst that shows high activities and efficiencies for pH-universal overall water splitting. [ABSTRACT FROM AUTHOR]

Electrochemical reduction of CO2 into energy‐dense chemical feedstock and fuels provides an attractive pathway to sustainable energy storage and artificial carbon cycle. Herein, we report the first work to use atomic Ir electrocatalyst for CO2 reduction. By using α‐Co(OH)2 as the support, the faradaic efficiency of CO could reach 97.6 % with a turnover frequency (TOF) of 38290 h−1 in aqueous electrolyte, which is the highest TOF up to date. The electrochemical active area is 23.4‐times higher than Ir nanoparticles (2 nm), which is highly conductive and favors electron transfer from CO2 to its radical anion (CO2.−). Moreover, the more efficient stabilization of CO2.− intermediate and easy charge transfer makes the atomic Ir electrocatalyst facilitate CO production. Hence, α‐Co(OH)2‐supported atomic Ir electrocatalysts show enhanced CO2 activity and stability. High‐density atomic Ir supported on α‐Co(OH)2 had outstanding performance for CO2 reduction to CO. The faradaic efficiency can reach 97.6 % with a TOF of 38 290 h−1. The high catalytic activity is attributed to more active sites for CO2 adsorption and activation and the higher efficiency in stabilizing the CO2.− intermediate. [ABSTRACT FROM AUTHOR]

Abstract: The practical use of overall water electrolysis is largely hindered by the need for precious noble metal‐based catalysts. Here, the colloidal synthesis of earth‐abundant electrocatalysts of Mo–Ni nanoparticles for efficient water splitting by thermal decomposition of Ni(acac)2 and Mo(CO)6 in the presence of 1‐octadecene and oleylamine at 320 °C is reported. It is shown that the optimized catalysts (Mo0.6Ni0.4) only require low overpotentials of 0.065 V for the hydrogen evolution reaction (HER) and of 290 mV for the oxygen evolution reaction (OER) to deliver a current density of 10 mA cm−2 in KOH (1.0 m). The as‐prepared Mo–Ni alloy nanoparticles also show extraordinary durability for both the HER and OER. A low potential of ≈1.62 V is required to yield a current density of 10 mA cm−2 when utilizing the alloy nanoparticles as bifunctional catalysts in a two‐electrode electrolyzer system. The ease of preparing either rigid or flexible high‐performance electrodes by making use of the alloy nanoparticle electrocatalysts without the need for binder further suggests the attractive application of colloidally stable nanoparticles in the field of electrochemical water splitting. [ABSTRACT FROM AUTHOR]

Highlights • A novel multi-dimensional Ni/NiCoP core/shell NHs was constructed. • The Ni/NiCoP NHs exhibits enhanced bifunctional HER and OER performances. • The interactions at the interface of Ni/NiCoP changed the electronic structures. • The Ni/NiCoP NHs reveal more optimal binding strength for H adatom and H 2 O molecule. • Only 1.57 V was needed for water splitting using Ni/NiCoP NHs at 10 mA·cm−2. Tuning structure, morphology and electronic state of electrocatalysts is essential to achieve highly efficient water splitting. Herein, we report synthesis of snap bean-like multi-dimensional core/shell Ni/NiCoP nano-heterojunctions (NHs) by adopting a solid phase transformation strategy. In the special structure, Ni nanoparticles are enclosed and strung by single phased NiCoP, forming strings of Ni/NiCoP core/shell heterojunctions, which showed improved stability and activity for both hydrogen evolution (HER) and oxygen evolution reactions (OER). X-ray photoelectron spectroscopy and synchrotron-radiation-based X-ray absorption spectroscopy reveal that interactions at the interface of Ni/NiCoP greatly changed electronic structures, which is a key intrinsic factor to underpin the enhanced electrocatalytic performance. Density functional theory calculations demonstrate Ni/NiCoP interface provide more optimal binding strength for H adatom and H 2 O molecule for HER, strong capture of hydroxyl, high valence Ni/Co species for OER. All these peculiarities facilitate the electrocatalytic process: only 1.57 V was needed to reach the current density of 10 mA·cm−2 for the overall water splitting using Ni/NiCoP NHs as both electrodes. This work demonstrates a facile strategy for synthesis of sophisticated catalytic interface at nano level and endows nano-heterojunction catalysts with enhanced performance for catalytic applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe2+-induced oxygen vacancy strategy was developed to construct robust OER catalysts. • Ni/β-FeOOH-1/CC shows an ultralow overpotential of 192 mV at 10 mA·cm−2. • The high OER activity is attributed to the massive oxygen vacancies and Ni doping. • Ni/β-FeOOH-1/CC can drive overall water splitting by dry battery or GaAs solar cell. • Ni/β-FeOOH-1/CC can realize an industrial-scale current density of 300 mA·cm−2. Abundant oxygen-vacancy and heteroatomic doping have been demonstrated to be beneficial to obtain high electrocatalytic performance for the oxygen evolution reaction (OER). In present work, a simple cathodic electrodeposition (CED) method based on Fe(II)-induced oxygen deficiency-metal doping (FeIIIOD/MD) strategy was developed to prepare robust water oxidation electrocatalysts. By using Fe2+ ions as the iron precursors, a series of Ni-doped β-FeOOH (Ni/β-FeOOH- x) on the carbon cloth (Ni/β-FeOOH- x /CC, here, the × is the molar percent of Fe2+ in the total ferric salt; x = 0, 0.2, 0.5, 0.8 or 1) electrocatalysts with different oxygen vacancy content were prepared. Relevant characterizations indicated that the oxygen-vacancy ratio and electrocatalytic OER performances of Ni/β-FeOOH-1/CC electrocatalysts prepared by using Fe2+ ions as the iron precursor is significantly higher than that of Fe3+. Fascinatingly, the Ni/β-FeOOH-1/CC with massive oxygen vacancies shows an ultralow overpotential of 192 mV at the current density of 10 mA·cm−2. Furthermore, the Ni/β-FeOOH-1/CC catalyst can also be directly driven by a dry cell or solar cell. More importantly, the Ni/β-FeOOH-1/CC catalyst prepared by CED method based on this FeIIIOD/MD strategy can realize water oxidation at the industrial current density, and it shows a potential industrial application value in the future. [ABSTRACT FROM AUTHOR]