Interface engineering of NiTe@CoFe LDH for highly efficient overall water-splitting

Construction of 3D Hierarchical Co3O4@CoFe-LDH Heterostructures with Effective Interfacial Charge Redistribution for Rechargeable Liquid/Solid Zn–Air Batteries

“…24,42 Given the unique advantages of Co-based catalysts, the heterostructured catalysts based on Co-based LDHs are expected to achieve high OER catalytic capacity, which has been of considerable interest in the field of water splitting lately. 43,44 Nevertheless, the application of such hybrid catalysts in ZABs and flexible energy storage devices still demands further exploration and improvement, while the comprehension of the interaction mechanisms between heterojunctions has yet to be deepened. Therefore, combining Co-based LDHs and oxides to construct 3D self-supporting heterostructures may be an appealing strategy to elevate electrocatalytic efficiency for liquid/solid ZABs, but simultaneously challenging.…”

“…To date, extensive efforts have been devoted to the earth-abundant transition metal-based compounds, which are regarded as highly promising candidates to replace precious metal-based catalysts. , In particular, cobalt (Co)-based layered double hydroxides (LDHs) or oxides with favorable catalytic activity are the focus of attention according to their richly variable valence states, good corrosion stability in alkaline medium, and environmental friendliness. − It is worth mentioning that, since an increase in the 3D energy band centers from late to early transition metals in the periodic table, Co-based catalysts exhibit higher binding energies for oxygen intermediates at the Co active site compared to the nickel (Ni)-based LDHs. , Unfortunately, the insufficiently exposed active sites of LDHs or the intrinsically low conductivity of oxides greatly restrict further improvements in the OER catalytic performance. , Quite a few recent studies have shown that the design strategies for specific nanostructures, such as self-supported nanosheets, nanotubes, nanowire arrays, and so forth, can usefully enhance the electrical conductivity and supply a high specific surface area with increased catalytic sites while successfully coping with the negative effects of binders. , More importantly, interfacial engineering, for example, three-dimensional (3D) core/shell heterostructure, can endow the composite catalysts with an outstanding electrocatalytic activity over their single-component counterparts, mainly due to the strong interfacial electronic coupling between different components. − A number of advanced non-precious metal catalysts possessing heterostructures continue to be reported. − Yu et al developed a composite electrocatalyst with highly efficient catalytic activity and excellent stability in alkaline media by tailoring cobalt tetroxide (Co 3 O 4 )/Co nano-heterojunctions in nitrogen-doped porous graphitized carbon frameworks . In addition, this approach can effectively avoid the aggregation and stacking of ultrathin LDHs to expose more active sites and accelerate mass diffusion. , Over the past few years, a series of catalysts integrating NiFe-LDH and transition metal oxides on metal substrates (e.g., nickel foam) to construct heterojunctions have displayed excellent OER catalytic performance for water splitting. , In the meantime, the relevant reports on energy storage devices mainly concentrate on liquid ZABs. , Given the unique advantages of Co-based catalysts, the heterostructured catalysts based on Co-based LDHs are expected to achieve high OER catalytic capacity, which has been of considerable interest in the field of water splitting lately. , Nevertheless, the application of such hybrid catalysts in ZABs and flexible energy storage devices still demands further exploration and...…”

Two-Dimensional Amorphous Cobalt Oxide Nanosheets/N-Doped Carbon Composites for Efficient Water Splitting in Alkaline Medium

“…Furthermore, these catalysts are unstable in a PEM environment . For both PEMWEs and AEMWEs, IrO 2 and RuO 2 are generally used as the state-of-the-art OER catalyst and commercial Pt/C are used as the state-of-the-art HER catalysts. , However, their low abundance and exorbitant cost prevent them from being applied extensively to water electrolysis . Thus, it is essential to develop a earth-abundant, cheaper, and noble-metal-free bifunctional electrocatalyst with tunable d-electron configuration for the development of AEMWEs …”

“…Because of low cost, high performance, and long-term stability toward water splitting in base, earth-abundant 3d-block transition metals, such as nickel, cobalt, and so forth, are much preferred for alkaline media . As transition metals have unfilled d-orbitals, they can easily lose and gain electrons, making them a sensible substitute for precious metals . The nonprecious as well as precious metal-based electrocatalysts were reported in the literature for HER, OER, and overall water splitting applications.…”

“…21 As transition metals have unfilled d-orbitals, they can easily lose and gain electrons, making them a sensible substitute for precious metals. 19 The nonprecious as well as precious metal-based electrocatalysts were reported in the literature for HER, OER, and overall water splitting applications. For example, Huo and co-workers 22 prepared Mo 2 C electrocatalysts for HER and other electrocatalytic applications.…”