Abbas, Syed Asad Iqbal, Muhammad Ibrahim Kim, Seong-Hoon Jung, Kwang-Deog 2024-01-20T02:03:40Z 2024-01-20T02:03:40Z 2021-09-01 2017-02-10 0013-4686 https://pubs.kist.re.kr/handle/201004/123065 Ni nanoparticles with different morphologies were synthesized for hydrogen evolution reaction (HER) in alkaline solution. Here, Ni(acac)2 was converted into Ni metal nanoparticles in solvothermal reactions with simple alcohols and oleylamine (OAm). The morphology of the resulting Ni nanoparticles was dependent mainly on the OAm/Ni molar ratio in alcohol solvent. Aggregates of spherical Ni nanoparticles (NiEt-OAml) were observed at the OAm/Ni molar ratio of 1.0, whereas two echinoid Ni nanoparticles (NiEt-OAm4 and NiEt-OAm6) could be prepared in ethanol at the OAm/Ni molar ratios of 4.0 and 6.0. Ni (OH)(2) formed in ethanol during a reaction time of 5 h was then reduced into echinoid Ni nanoparticles after 8 h. Echinoid Ni nanoparticles were formed by atomic addition on the tops of the multipod Ni particles formed via Ni(OH)(2)/NiO aggregates. Webbed feet-like particles (NiIPA-OAm4) with plate edges were also observed in isopropanol under the same reaction conditions. The catalytic activities of the prepared Ni nanoparticles for the hydrogen evolution reaction were evaluated in alkaline solution. The NiEt-OAm4 with urchin-like morphology was much more active than the NiIPA-OAm4 with webbed feet like morphology. The exchange current density of Ni catalysts was increased with increasing the OAm/Ni molar ratio. The NiEt-OAm6 exhibited an exchange current of 0.191 mA cm(-2) and the NiEt-OAm4 exceeded electrocatalytic performance of a commercial Pt catalysts (40% Pt on Vulcan XC 72) in a stability test for 100 kiloseconds at -1.5 V (vs. Hg/HgO) in 1.0 M NaOH due to its high stability. (C) 2017 Elsevier Ltd. All rights reserved. English PERGAMON-ELSEVIER SCIENCE LTD BRANCHED METAL NANOSTRUCTURES PT BIMETALLIC NANODENDRITES PLATINUM NANOPARTICLES EFFICIENT ELECTROCATALYST GOLD NANOPARTICLES ANISOTROPIC GROWTH WATER ELECTROLYSIS NICKEL-HYDROXIDE OXYGEN REDUCTION CARBON-DIOXIDE Catalytic Activity of Urchin-like Ni nanoparticles Prepared by Solvothermal Method for Hydrogen Evolution Reaction in Alkaline Solution Article 10.1016/j.electacta.2017.01.039 1 ELECTROCHIMICA ACTA, v.227, pp.382 - 390 ELECTROCHIMICA ACTA 227 382 390 scie scopus 000394399600042 2-s2.0-85009223215 Electrochemistry Electrochemistry Article BRANCHED METAL NANOSTRUCTURES PT BIMETALLIC NANODENDRITES PLATINUM NANOPARTICLES EFFICIENT ELECTROCATALYST GOLD NANOPARTICLES ANISOTROPIC GROWTH WATER ELECTROLYSIS NICKEL-HYDROXIDE OXYGEN REDUCTION CARBON-DIOXIDE Branching Ni nanoparticles Multipod Solvothermal method Hydrogen evolution reaction