• Title/Summary/Keyword: $Ni(OH)_2$ microcrystals

Search Result 3, Processing Time 0.017 seconds

Synthesis of Fe-doped β-Ni(OH)2 microcrystals and their oxygen evolution reactions (Fe 도핑된 β-Ni(OH)2 마이크로결정 합성과 산소발생반응 특성)

  • Je Hong Park;Si Beom Yu;Seungwon Jeong;Byeong Jun Kim;Kang Min Kim;Jeong Ho Ryu
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.33 no.5
    • /
    • pp.196-201
    • /
    • 2023
  • In order to improve the efficiency of the water splitting system for hydrogen energy production, the high overvoltage in the electrochemical reaction caused by the catalyst in the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) must be reduced. Among them, transition metal-based compounds (hydroxide, sulfide, etc.) are attracting attention as catalyst materials to replace currently used precious metals such as platinum. In this study, Ni foam, an inexpensive metal porous material, was used as a support and β-Ni(OH)2 microcrystals were synthesized through a hydrothermal synthesis process. In addition, changes in the crystal morphology, crystal structure, and water splitting characteristics of β-Ni(OH)2 microcrystals synthesized by doping Fe to improve electrochemical properties were observed, and applicability as a catalyst in a commercial water electrolysis system was examined.

Effects of Mo co-doping into Fe doped β-Ni(OH)2 microcrystals for oxygen evolution reactions (Fe-doped β-Ni(OH)2의 산소발생반응 증가를 위한 Mo의 동시도핑효과)

  • Je Hong Park;Si Beom Yu;Tae Kwang An;Byeong Jun Kim;Jeong Ho Ryu
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.34 no.1
    • /
    • pp.30-35
    • /
    • 2024
  • In order to improve the efficiency of the water splitting system for hydrogen production, the high overvoltage in the electrochemical reaction caused by the catalyst in the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) must be reduced. Among them, transition metal-based compounds are attracting attention as catalyst materials that can replace precious metals such as platinum that are currently used. In this study, nickel foam, an inexpensive metal porous material, was used as a support, and Fe-doped β-Ni(OH)2 microcrystals were synthesized through a hydrothermal synthesis process. In addition, in order to improve OER properties, changes in the shape, crystal structure, and water splitting characteristics of Fe-Mo co-doped β-Ni(OH)2 microcrystals synthesized by co-doping with Mo were observed. The changes in the shape, crystal structure, and applicability as a catalyst for water splitting were examined.

Electrocatalytic properties of Te incorporated Ni(OH)2 microcrystals grown on Ni foam

  • Lee, Jung-Il;Oh, Seong Gyun;Kim, Yun Jeong;Park, Seong Ju;Sin, Gyoung Seon;Kim, Ji Hyeon;Ryu, Jeong Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.31 no.2
    • /
    • pp.96-101
    • /
    • 2021
  • Developing effective and earth-abundant electrocatalyst for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is critical for the commercialization of a water splitting system. In particular, the overpotential of the OER is relatively higher than the HER, and thus, it is considered that one of the important methods to enhance the performance of the electrocatalyst is to reduce the overpotential of the OER. We report effects of incorporation of metalloid into Ni(OH)2 microcrystal on electrocatalytic activities. In this study, Te incorporated Ni(OH)2 (��Te-Ni(OH)2) were grown on three-dimensional porous NF by a facile solvothermal method with �� = 1, 3 and 5. Homogeneous microplate structure on the NF was clearly observed for the Ni(OH)2/NF and ��Te-Ni(OH)2/NF samples. However, irregular and collapsed nanostructures were found on the surface of nickel foam when Te precursor ratio is (��) over 3. Electrocatalytic OER properties were analysed by Linear sweep voltammetry (LSV) and Electrochemical impedance spectroscopy (EIS). The amount of Te incorporation used in the electrocatalytic reaction was found to play a crucial role in improving catalytic activity. The optimum Te amount (��) introduced into the Ni(OH)2/NF was discussed with respect to their OER performance.