Recasting Ni-foam into NiF2 nanorod arrays via a hydrothermal process for hydrogen evolution reaction application

Hydrogen Evolution Reaction Activities of Room-Temperature Self-Grown Glycerol-Assisted Nickel Chloride Nanostructures

Three-dimensional nanomaterials of desired structural/morphological properties and highly porous with a high specific surface area are important in a variety of applications. In this work, glycerol-mediated self-growth of 3-D dandelion flower-like nickel chloride (NiCl2) from nickel-foam (NiF) is obtained for the first time using a room-temperature (27 °C) processed wet chemical method for electrocatalysis application. Glycerol-mediated self-grown NiCl2 flowers demonstrate an excellent electrocatalytic performance towards the hydrogen evolution reaction (HER), which is much superior to the NiF (303 mV) and NiCl2 electrode prepared without glycerol (208 mV) in the same electrolyte solution. With a Tafel slope of 41 mV dec−1, the NiCl2 flower electrode confirms improved reaction kinetics as compared to the other two electrodes, i.e., NiF (106 mVdec−1) and NiCl2 obtained without glycerol (56 mV dec−1). The stability of the glycerol-based NiCl2 electrode has further been carried out for 2000 cycles with the overpotential diminution of just 8 mV, approving an electrocatalyst potential of glycerol-based NiCl2 electrode towards HER kinetics. This simple and easy growth process involves nucleation, aggregation, and crystal growth steps for producing NiCl2 nanostructures for electrocatalytic water splitting application through the HER process.

Facile fabrication of self-supporting porous CuMoO4@Co3O4 nanosheets as a bifunctional electrocatalyst for efficient overall water splitting

Research shows that redox complementarity and synergism among the ingredients of heterogeneous catalysts can enhance the performance of the catalyst. In this research, a porous CuMoO₄@Co₃O₄ nanosheet electrocatalyst is prepared, which is uniformly decorated on nickel foam (NF) by hydrothermal reactions and the impregnation method. The CuMoO₄@Co₃O₄ is an efficient bifunctional catalyst with prominent electrocatalytic activity and durability. It requires overpotentials of only 54 and 251 mV to obtain current densities of 10 and 50 mA cm^-2 for the cathodic hydrogen evolution reaction (HER) and the anodic oxygen evolution reaction (OER) in 1.0 mol L^-1 KOH, corresponding to Tafel slope values of 98.8 and 87.4 mV dec^-1, respectively. Furthermore, the CuMoO₄@Co₃O₄ shows excellent stability of 120 h chronopotentiometry at a current density of 100 mA cm^-2 for the HER/OER. Notably, an alkaline electrolyzer (with CuMoO₄@Co₃O₄ as the HER and OER electrodes) can deliver a current density of 10 mA cm^-2 at a low voltage of 1.51 V. The catalytic activity of CuMoO₄@Co₃O₄ can be attributed to the structure of the porous nanosheets and the synergistic effect between CuMoO₄ and Co₃O₄.

Recent advances in cobalt-based catalysts for efficient electrochemical hydrogen evolution: a review

Hydrogen (H2) is a new type of renewable energy that can meet people's growing energy needs and is environmentally friendly. In order to improve the industrial application prospect and electrochemical...