A pine‐shaped Pt nanostructured electrode with under‐water superaerophobicity for ultrahigh and steady hydrogen evolution reaction (HER) performance is successfully fabricated by a facile and easily scalable electrodeposition technique. Due to the lower bubble adhesive force (11.5 ± 1.2 μN), the higher bubble contact angle (161.3° ± 3.4°) in aqueous solution, and the smaller size of bubbles release for pine‐shaped Pt nanostructured electrode, the incomparable under‐water superaerophobicity for final repellence of bubbles from submerged surface with ease, is successfully achieved, compared to that for nanosphere electrode and for Pt flat electrode. With the merits of superior under‐water superaerophobicity and excellent nanoarray morphology, pine‐shaped Pt nanostructured electrode with the ultrahigh electrocatalytic HER performance, excellent durability, no obvious current fluctuation, and dramatically fast current density increase at overpotential range (3.85 mA mV−1, 2.55 and 13.75 times higher than that for nanosphere electrode and for Pt flat electrode, respectively), is obtained, much superior to Pt nanosphere and flat electrodes. The successful introduction of under‐water superaerophobicity to in‐time repel as‐formed H2 bubbles may open up a new pathway for designing more efficient electrocatalysts with potentially practical utilization in the near future.

show superb activities than either of the parent metal catalyst, and comparable to the best noble catalysts (e.g., IrO 2 and RuO 2 ) [ 12 ] for oxygen evolution reaction (OER), which is a key component for a number of energy storage and conversion processes. [ 13 ] However, the lack of investigations on the oxygen reduction reaction (ORR) activities of LDHs greatly limits their further application in rechargeable metal-air battery and unitized regenerative fuel cell. Thus it is intriguing to evaluate the bifunctional performance of LDH-based materials in order to broadening the usages in electrochemistry.The specifi c activity of the material for the target reaction is usually highly dependent on the chemical composition and their electronic structures. [ 14,15 ] For OER, it is found that a small amount of Fe doping was effective for enhancing the OER activities of Ni hydroxides or oxides, possibly due to the enhanced structure disorder and conductivity. [ 16 ] Recently, an excellent OER performance was observed on amorphous NiCoFe oxides which were prepared by a photochemical route. [ 17 ] As to the ORR, Co and Fe ions are believed to be the active center with specifi c crystal and electronic structures. [ 18,19 ] Moreover, Co-based compounds have been widely studied recently as bifunctional materials for oxygen electrocatalysis. [ 20 ] LDHs, which offer a wide tunability of diverse metal species and ratios in the intralayer as well as a large interlayer spacing which may accelerate the ion diffusion, should be of great potential with high bifunctional performance.In this work, the ORR and OER activities of trinary NiCoFe-LDHs have been systematically investigated. It is observed that the NiCoFe-LDH showed a reasonable bifunctional performance while the sample after preoxidation treatment (denoted as O-NiCoFe-LDH) would lead to a signifi cant enhancement. This improvement was attributed to the formation of Co 3+ in the intralayer, result in the conductivity improvement of the material. To demonstrate the practical application of the LDH catalyst, the O-NiCoFe-LDH loaded on Tefl on-treated carbon fi ber paper (T-CFP) only required a potential hysteresis of ≈800 mV to achieve stable current densities of ≈20 mA cm −2 for ORR and OER for matching the current requirement of rechargeable zinc-air batteries, [ 21 ] much smaller than those of the commercial 60 wt% Pt/C and 20 wt% Ir/C catalysts. This fi rst investigation on the bifunctional performance of LDHs not Layered double hydroxides (LDHs) are a family of high-profi le layer materials with tunable metal species and interlayer spacing, and herein the LDHs are fi rst investigated as bifunctional electrocatalysts. It is found that trinary LDH containing nickel, cobalt, and iron (NiCoFe-LDH) shows a reasonable bifunctional performance, while exploiting a preoxidation treatment can signifi cantly enhance both oxygen reduction reaction and oxygen evolution reaction activity. This phenomenon is attributed to the partial conversion of Co 2+ to Co 3+ state in the pr...

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Due to the unique structural advantages, hierarchical Co3O4@NiO nanoarrays can be regarded as advanced electrodes for Ni–Zn batteries.

Ni-rich LiNi0.6Co0.2Mn0.2O2 nanomaterials with a high percentage of exposed {010} facets have been prepared by surfactant-assisted hydrothermal synthesis followed by solid-state reaction. Characterization by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) confirmed that the particles have enhanced the growth of nanocrystal planes in favor of Li-ion diffusion. Electrochemical tests show these cathode materials endow a large Li-ion diffusion coefficient, which leads to a superior rate capability and cyclability, suggesting these cathode materials are highly beneficial for practical application in Li-ion batteries.