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The fundamental obstacle that only a few part of hydrogen energy is currently produced by industrial electrocatalysis, is in insufficient performance and high cost of even the most advanced catalysts. To meet the demand for high-performance, lasting catalysts at industry-relevant current densities (≥500 mA cm-2) with overpotentials ≤300 mV, here, we uniquely heterointerface the Ni, Co, and W phosphoxide phases in situ on plasma-defect-engineered Ni-Co support (MxO@MxP/PNCF (M = Ni, Co, W) core-shell heterostructure) to dramatically enhance the electrocatalytic performances with very high current densities. The achieved H2 evolution requires low overpotentials of only 53 and 343 mV for current densities of 10 (j10) and 1000 mA cm-2 (j1000) and shows fast reaction kinetics with a small Tafel slope of 40 mV dec-1. Importantly, the MxO@MxP/PNCF presents spectacular activity at industry-relevant current densities (>j300) and outperforms the industry Pt/C benchmark. Our catalyst shows excellent long-term stability and durability with no significant activity loss after 104 cycles and 100 h of operation in an alkaline electrolyte. First-principles simulations reveal the best metal-phosphide combination to minimize the Gibbs energy for absorbing H+ ions on the reactive sites and to enhance the desorption of H2.

In-situ engineering of nonprecious catalysts with highly electrocatalytic performances for H2 or O2 generation is one of unresolved challenges in industrial chemistry. In this work, a trimetallic (...

Hydrogen is a source of sustainable and clean energy poised to replace fossil fuels. Bifunctional electrocatalysts are actively pursued to simultaneously drive the two key reactions, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), for hydrogen production by electrolysis water. One of the most promising candidates based on bimetallic layered double hydroxide salts (LHSs) and cobalt-based organic framework (ZIF-67) suffer from poor interface coupling. Herein, we present a new approach based on fusing NiCo LHSs nanowire arrays with ZIF-67 to fabricate three-dimensional flower-like structures on a Ni-Fe foam support. To improve interfacial coupling and catalytic performance, simple oxidation, carbonization, sulfurization, and selenization are performed to study the effects of different post-treatments and discover the optimum bifunctional electrocatalysts. The optimized S-doped catalyst reveals the highest electrocatalytic characteristic quantified by the low overpotentials of 170 and 100 mV for OER and HER at 10 mA cm -2 in 1 M KOH, respectively. This outstanding electrocatalytic property is ascribed to strong interfacial coupling between the NiCo-LHSs and ZIF-67 derivatives, as well as the rational electronic structures, dense catalytic active sites, and large specific surface area. This work opens new prospects for fabricating efficient and low-cost electrocatalysts for renewable hydrogen energy production.

Rational design of noble-metal-free electrocatalysts with excellent performance for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is critical for next-generation industrial applications of water electrolysis. Here, a simple and robust preparation method of three-dimensional (3D) nanostructured catalysts made of abundant metals is presented. The 3D hydrangea-like microspheres made of nickel–vanadium double hydroxide nanosheets are first prepared on the Ni–Co foam (NCF) followed by the hydroxides exchange with (MoS4)2– ions to form Chevrel-phase Ni–V–Mo sulfide. Benefiting from the 3D holey nanostructures with a large surface area, low adsorption free energy values, and fast electronic transport, the overpotentials of the optimized Ni8V2(Mo3S4)11/NCF catalyst for HER and OER at a current density 10 mA cm–2 are as low as 129 and 330 mV, respectively. The amounts of H2 and O2 generated at a current density of 10 mA cm–2 are about 517 and 342 μmol h–1, which is very competitive wit...

A facile and effective strategy for fabricating a three-dimensionally (3D) structured nanocomposite catalyst based on nonprecious metals for water splitting in alkaline electrolyzers is reported in this paper. This nanocomposite catalyst consists of the CdS quantum dots (QDs) decorated Ni3S2 nanosheet flowers deposited on the plasma-treated nickel foam (PNF). The NiO formed during the plasma treatment is shown to play an important role for pushing the hydrogen and oxygen evolution reactions (HER and OER) in alkaline media. The enhanced exposure of active sites on the nanopetalages results in superior catalytic performance for promoting HER and OER in alkaline electrolyzers. Specifically, a current density of 10 mA cm–2 can be achieved for the HER with a 121 mV overpotential when the working electrode based on the 1 mM CdS/Ni3S2/PNF catalyst is employed in 1 M KOH. The corresponding Tafel slope is 110 mV/decade. For the OER, the onset potential can be as low as 1.25 V vs reversible hydrogen electrode (RHE)...