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Metal–support interaction (MSI) is considered a key effect of electronic and geometric structures of catalysts on tuning catalytic performance. The oxygen evolution reaction (OER) is a crucial process during energy conversion and storage. However, the OER process requires the help of noble metal catalysts to reduce the reaction overpotential, enhance reactivity with intermediates, and maintain good operating stability. Carbon–supported metal catalysts have been considered candidates for noble metal catalysts for OER. MSI occurs at the interface of carbon supports and metals, affecting the catalytic performance through electronic and geometric modulation. MSI can influence the catalytic performance and change reaction pathways from charge redistribution, electron transfer, chemical coordination and bonding, and steric effect. Connecting MSI effects with the OER mechanism can provide theoretical guidance and a practical approach to the design of efficient catalysts, including the modulation of particle size, morphology, heteroatom doping, defect engineering, and coordination atom and number. Advantage can be taken of MSI modulation between metal compounds and carbon supports to provide guidance for catalyst design. [ABSTRACT FROM AUTHOR]

A highly efficient bifunctional metal‐free catalyst was prepared by growth of three‐dimensional porous fluorographdiyne networks on carbon cloth (p‐FGDY/CC). Our experiments and density functional theory (DFT) calculations show the 3D p‐FGDY/CC network is highly active and it is a high potential metal‐free catalyst for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), as well as overall water splitting (OWS) under both acidic and alkaline conditions. The experimental and theoretical results show very good consistency; for example, in the HER process, p‐FGDY/CC exhibits small overpotentials of 82 and 92 mV to achieve 10 mA cm−2 under alkaline and acidic conditions, respectively. This ensures an even higher selectivity for the adsorption/desorption of various O/H intermediate species. The essential key promotion accomplishes a bifunctional H2O redox performance application under pH‐universal electrochemical conditions. [ABSTRACT FROM AUTHOR]

Abstract The controlled synthesis of graphdiyne-wrapped cobalt nitride nanosheets and their direct application as a bifunctional electrocatalyst towards electrical splitting water was reported for the first time. Because of its unique electronic and chemical structure, the electrocatalyst has high activity and stability in electrocatalysis process of 1.0 M KOH. The catalyst embedded by graphdiyne showed excellent catalytic performance of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) with low overpotentials of 70 mV and 260 mV, respectively, at 10 mA cm−2, which was obviously superior to that of the commercial Pt/C and RuO 2 , respectively. As both the anode and cathode in a two-electrode alkaline electrolyzer, 10 mA cm−2 can be obtained at an ultralow cell voltage of 1.48 V which is much smaller than that of Pt/C RuO 2 couple. Graphical abstract Summary of the research:A new graphdiyne-wrapped cobalt nitride nanosheets array has been demonstrated to be an efficient HER/OER bifunctional electrocatalyst towards overall water splitting in alkaline conditions, exhibiting outstanding catalytic performances superior to that of commercial Pt/C for HER and RuO 2 for OER, respectively. Image 1 Highlights • An in-situ growth method was applied to synthesize graphdiyne-wrapped cobalt nitride nanosheets. • The graphdiyne triggered an energy favorable way for efficient water splitting. • The resulting products exhibit outstanding catalytic performances superior to that of Pt/C for HER and RuO 2 for OER. [ABSTRACT FROM AUTHOR]

High-entropy catalysts attract rising attention for promoting oxygen evolution reaction (OER) due to the advantages of multiple catalytic active sites, unique lattice distortion effect, interatomic d-band ligand effect, etc. However, it still needs to design new high-entropy catalysts with low cost and high efficiency to meet the requirement of large-scale applications. In this study, AlNiCuCoFeY amorphous alloy ribbon is prepared by melt spinning method. Then, the ribbon is etched in HF solution to form a nanoparticle modified ribbon, whose superficial species are further conversed to high-entropy oxides/Al alloy (HEO/Al alloy) or high-entropy fluorides/Al alloy (HEF/Al alloy) heterogeneous nanoparticles with a diameter of ∼20 nm by subsequent oxidization or fluorination process. Herein, the oxidized metallic elements with high valence state can promote the adsorption of OER. Due to the large surface area, multiple active sites, and the synergistic effect of different species, the HEO/Al alloy or HEF/Al alloy composite only need 293 and 261 mV overpotential to afford 10 mA cm−2 current density. This work discusses the design of high-entropy electrocatalysts and demonstrated a promising route to improve their OER electrocatalytic performance. [Display omitted] • AlNiCuCoFeYO x and AlNiCuCoFeYF x high-entropy catalyst with high efficiency are obtained. • The crucial role of introduction of O and F elements in high-entropy catalyst is discussed. • AlNiCuCoFeYO x and AlNiCuCoFeYF x nanocrystals are mixed with amorphous AlNiCuCoFeY nanocrystal. • HEO/Al alloy and HEF/Al alloy need 293 and 261 mV overpotentials @ 10 mA cm−2 current density. [ABSTRACT FROM AUTHOR]