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The widespread use of unsustainable fossil fuels has caused serious damage to the ecological environment. The development of sustainable clean energy is urgent. Producing hydrogen by water electrolysis can effectively solve fossil energy shortage and environmental pollution issues. The preparation of inexpensive, efficient, and stable electrocatalytic hydrogen evolution electrode materials is the key to achieving the application of electrocatalytic hydrogen evolution. Herein, the amorphous nickel oxide/nickel foam (NiO x /NF) hydrogen evolution electrode was prepared by a simple one-step hydrothermal method with hydrogen peroxide as an oxidant. The amorphous leaf array structure of NiO x /NF electrode can enrich the surface composition and expose more catalytic active sites. Further, hydrogen peroxide etching can optimize the electronic structure of NiO x , and accelerate the electron migration. Thus, NiO x /NF displays excellent alkaline hydrogen evolution activity with the low over potentials of 70, 318 and 361 mV at 10, 500 and 1000 mA cm−2, respectively, leading to high performance in alkaline HER than those of reported Ni-based electrodes and even surpasses commercial Pt/C at high current density. Our work provides a new approach for developing inexpensive electrocatalysts with excellent alkaline hydrogen evolution activity and stability. [Display omitted] • Amorphous NiO X /NF electrocatalyst was developed in a simple hydrothermal process with hydrogen peroxide as an etchant. • Hydrogen peroxide etching optimized the electronic structure of NiO X , and increased the electron transfer rates. • NiO X /NF exhibited admirable alkaline HER activity (η 10 of 70 mV, 68.2 mV dec-1) and excellent long-term stability. • NiO X /NF displayed obvious advantages at a practical current density of 500 mA cm-2 over commercial Pt/C. [ABSTRACT FROM AUTHOR]

Multiphasic fish-gill-like NiCoP@Co 0.5 Ni 0.5 Se 2 heterostructure with an extremely high stability is fabricated as high performance electrocatalyst for high current density hydrogen evolution. This work provides an innovative approach to efficient electrocatalysts of industrial potential. [Display omitted] • A fish-gill-like heterostructure NiCoP@Co 0.5 Ni 0.5 Se 2 /NF is created. • Water and hydrogen adsorption kinetics are optimized. • NiCoP@Co 0.5 Ni 0.5 Se 2 /NF achieves a high-current-density of 671 mA cm−2 at 250 mV. • An excellent overall water splitting performance is realized. Multiphasic engineering is powerful to improve the performance of hydrogen evolution. Here, NiCoP@Co 0.5 Ni 0.5 Se 2 heterostructure with a fish-gill-like morphology has been initially prepared via an epitaxial controlled growth strategy. When used as catalyst in the hydrogen evolution, this heterostructure gives low overpotential of 235 mV and long-term durability of 100 h at high current density of 500 mA cm−2 in 1.0 M KOH, showing a superior activity and excellent stability. Such superior performances are achieved by its 3D multiphasic heterostructure and optimized interface electronic structure because extremely porous superhydrophilic and superaerophobic surface of hierarchical morphology enhance kinetic of hydrogen evolution. The findings reported in this work open new occasion for creating novel technologies based on nature-inspired strategy and multiphasic engineering, as evidenced by a superior overall water splitting performance of an assembled NiCoP@Co 0.5 Ni 0.5 Se 2 /NF‖NiFe-LDH/NF cell under industrial condition (30 % KOH, 25 and 60 °C). [ABSTRACT FROM AUTHOR]

Powerful, efficient, and corrosion-resistant electrocatalysts are in need to achieve high-current-density neutral seawater hydrogen evolution. Here, a novel strategy through strong metal-support interaction (SMSI) and incorporation of Pt to construct PtNb-Nb 2 O 5 clusters @C was developed with stable high-current-density neutral seawater hydrogen evolution property for the first time. SMSI prevents agglomeration and corrosion of nanomaterials. Pt sites were proposed to play an anabranch role by binding H* to stabilize the Nb valence state and prevent water dissociation incapacitation. The optimized PtNb-Nb 2 O 5 @CC delivers low overpotentials of 440 mV (500 mA cm−2) and 570 mV (1000 mA cm−2) in neutral seawater and has 360 h excellent durability at 500 mA cm−2. In-situ Fourier transform infrared spectroscopy (FTIR), in-situ Raman spectroscopies and theoretical calculations supported the hydrogen evolution reaction (HER) mechanism. PtNb-Nb 2 O 5 heterogeneous interface provided more active sites for water dissociation. OH* adsorbed on Nb sites in stable Nb 2 O 5 , and H* adsorbed on Nb sites and desorbed as H 2 on Pt sites in stable PtNb. Overall, this work not only first achieves stable high-current-density neutral seawater hydrogen evolution property, but also opens a new opportunity to explore SMSI and incorporation of Pt to prevent agglomeration, corrosion, and water dissociation incapacitation for catalytic applications under high current densities. [Display omitted] • A novel strategy through strong metal-support interaction and incorporation of Pt was proposed. • This strategy can prevent agglomeration, corrosion and water dissociation incapacitation. • PtNb-Nb 2 O 5 clusters @C was synthesized by solvent-free microwave method. • Stable high-current-density neutral seawater hydrogen evolution property was achieved. • In-situ characterizations and theoretical calculations demonstrate the reaction mechanism. [ABSTRACT FROM AUTHOR]

Abstract: New self-ordering porous alumina films were fabricated in organic acid electrolytes. Highly ordered cell arrangements of porous alumina films were realized in malonic acid at 120V and tartaric acid at 195V having 300nm and 500nm pore intervals, respectively. Self-organization was achieved at the maximum voltage required to induce high-current-density anodization while preventing burning, i.e., an extremely high-current flow concentrated at local points. The cells of the film grown at a high field must be pressed against each other, so that the self-ordering proceeds with the porous layer growth. When the self-ordering of cell arrangement proceeds, the cells became smaller. To improve the regularity of the cell configuration, a low electrolyte temperature and a relatively high electrolyte concentration were effective for maintaining a high-current-density to prevent burning. Surface flatness was an essential factor for self-ordering, however, the surface oxide film produced by electropolishing an aluminum substrate prevented quick pore growth in the organic acids having a low dissociation constant. It is confirmed that electropolishing followed by alkaline treatment was most appropriate as the pre-treatment in preparing flat surfaces. [Copyright &y& Elsevier]

The magneto-impedance (MI) effect in amorphous and current annealed Fe73.5Cu1Nb3Si13.5B9 wires has been measured to investigate the influence of DC annealing, high-current-density electropulsing annealing and tensile stress on it. The results show that the MI of DC annealed sample exhibits sharp maximum at Hex=Hk. Maximum MI ratio of 60% is observed in sample of high-current-density electropulsing annealed under applied tensile stress. [Copyright &y& Elsevier]