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For the catalyst for water splitting, low overpotential and longer stability is very important. Here, we developed a simple strategy to prepare an efficient catalyst for oxygen evolution by partially phosphating NiFe-LDH and then etching and growing Prussian blue analogues on it. Benefiting from its unique hierarchical structure, the synthesized NiFeCo PBA-NiFeP catalyst showed excellent electrocatalytic performance in 1 M KOH. At 100 mA/cm2, the overpotential of the oxygen evolution reaction (OER) is only 245 mV and exhibits stability for over 50 h. This is superior to most of the OER catalysts reported so far. Its excellent performance is due to its unique hierarchical structure and the synergistic effect between polymetals, which enables it to have abundant active sites and efficient electron transfer. This controllable and universal strategy will provide a new idea for developing interfacial composites and preparing high efficiency electrocatalysts. • A new NiFeCo-PBA-NiFeP composite was prepared by hydrothermal-phosphating-etching process. • The unique hierarchical structure facilitates gas release and contact between the active site and the solution. • The synergistic effect between multiple metals improves the OER properties of the materials. • The combination of NiFeP and NiFeCo PBA improves the OER performance of the material. [ABSTRACT FROM AUTHOR]

[Display omitted] Sluggish kinetics of the oxygen evolution reaction during the water splitting requires high-performance electrocatalysts with low cost and good stability. Metal-organic frameworks (MOFs) have attracted much attention as electrocatalysts owing to their unique properties. To improve their electrocatalytic activity and stability, we report a selenylation method to modulate the morphology and interfaces by forming flower-like MOF-selenide nanocomposites. The optimal sample exhibits high activity with an overpotential of 260 mV at 10 mA cm−2, much better than commercial RuO 2 and the control samples. Moreover, the optimal sample has the lowest Tafel slope of 54.3 mV dec-1, indicating the fast reaction kinetics, which can be attributed to the lower charge-transfer resistance and high intrinsic activity. Chronoamperometry shows that the optimal sample can maintain the current density for 60 h at 10 mA cm−2 after the initial surface reconstruction, demonstrating good stability. This study provides a new perspective on the development of highly efficient electrocatalysts based on polymetallic MOFs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Heterogeneous MnNiCoP/FeOOH was successfully prepared by electrodeposition phosphating electrodeposition. • The interfacial synergism results in excellent HER and OER electrocatalytic activity and stability. • The catalyst can provide 1.627 V battery voltage at 100 mA cm−2, and shows good stability and durability. The production of three-dimensional heterogeneous structures is a vital approach for the creation of high-performance bifunctional electrocatalysts. Herein, three-dimensional heterostructure MnNiCoP/FeOOH (MNC-P/FeOOH) supported by Ni foam was prepared by simple electrodeposition and phosphorylation as a bifunctional electrocatalyst. The results showed that the required overpotential for MNC-P/FeOOH catalyst to reach 100 mA cm−2 current density was 124 mV and 251 mV in 1.0 M KOH solution, respectively. Construction of heterojunction not only improves the OER performance of MnNiCoP, but also reduces the potential required to drive the integral water splitting at 100 mA cm−2 current density. The electrocatalytic activity of MNC-P/FeOOH is greatly increased due to a distinctive interface synergy and strong electronic contacts in the MNC-P/FeOOH heterojunction. This design approach of bifunctional transition metal phosphides provides a potential route to achieve total water splitting. [ABSTRACT FROM AUTHOR]

Electronic structure regulation is one of the essential strategies for developing advanced electrocatalysts. Herein, FeOOH was electrodeposited on the surface of NiSe 2 /Ni 2 O 3 , resulting in a layered NiSe 2 /Ni 2 O 3 /FeOOH interfacial composite with a unique hierarchical structure and strong electronic interactions. This sheet-like nanostructure provides sufficient space for mass transfer, fully exposes the active sites, and accelerates the reaction kinetics. The optimal sample exhibits excellent oxygen evolution reaction (OER) activity with a low overpotential of 270 mV at a current density of 100 mA cm−2 and a Tafel slope of only 54.7 mV dec−1. It also has excellent durability. This study provides a new perspective for developing efficient electrocatalysts by constructing interfacial composites. [Display omitted] • Construction of nanocomposites was built by facile electrodeposition. • The electrocatalyst exhibits an overpotential of 270 mV and a Tafel slope of 54.7 mV dec−1 at 100 mA cm−2. • Interfacial electron redistribution is the fundamental reason for improving electrocatalytic performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • NiCoP electrocatalyst was prepared by two-step hydrothermal phosphating process. • A simple and controllable method was used to construct layered porous plates to reduce the charge transfer resistance of NiCoP materials and showed the best catalytic performance. • NiCoP porous sheet has a large electrochemical active surface area and catalytic activity and the stability of the catalyst was investigated. Research on the stable and high-efficiency transition metal-based electrocatalyst to achieve hydrogen evolution reaction (HER) becomes one of the core solutions for water decomposition. Non-precious metals phosphide has the potential to become a non-noble metal electrocatalyst due to its good electronic structure effect, extremely low price, and expected durability in a larger pH range. In this paper, hexagonal NiCoP porous nanosheets were synthesized using a facile hydrothermal and post-phosphating method. We anticipate that bimetal doping can further enhance electrocatalyst activity as well as improve the capability of absorbing hydrogen from the materials by modifying the electronic structure. The obtained NiCoP electrocatalyst behaves outstanding catalytic performances for HER in alkaline media with 83 mV initial overpotential at 10 mA cm−2, as well as the low Tafel slopes of 41 mV dec−1. In addition, the current density showed almost no attenuation in the 10 h chronoamperometry experiment. The outstanding catalytic function can be attributed to the nanosheets with many orifices, which can expand the effective reaction specific surface area, promote mass transport and boost the water decomposition efficiency. And the collaboration of Ni and Co in NiCoP nanosheets can also improve the electrochemical function. Moreover, the current work offers a feasible approach for synthesizing a cheap and efficient NiCoP electrocatalyst for HER, which is especially appealing to practical application. [ABSTRACT FROM AUTHOR]