Hexagonal β-Ni(OH)2 nanoplates with oxygen vacancies as efficient catalysts for the oxygen evolution reaction
2019; Elsevier BV; Volume: 324; Linguagem: Inglês
10.1016/j.electacta.2019.134868
ISSN1873-3859
AutoresNam Il Kim, Dongwook Lim, Yeji Choi, Sang Eun Shim, Sung‐Hyeon Baeck,
Tópico(s)Supercapacitor Materials and Fabrication
ResumoWater splitting system by transition metal-based catalysts has drawn much attention in renewable energy storage and conversion system. In this study, β-Ni(OH)2 nanoplates with abundant oxygen vacancies were synthesized via the hydrothermal method followed by a partial reduction reaction in a mild hydrogen atmosphere, and applied to the oxygen evolution reaction (OER) in an alkaline solution. The β-Ni(OH)2 nanoplates prepared by partial reduction in a hydrogen atmosphere at 100 °C exhibited a current density of 10 mA cm−2 at a low overpotential of 340 mV in 1 M KOH; the overpotential was much lower than those required for pristine β-Ni(OH)2 nanoplates (391 mV) and air-treated β-Ni(OH)2 nanoplates (369 mV). Furthermore, the H2-treated β-Ni(OH)2 nanoplates also displayed outstanding long-term stability even after 1000 cyclic voltammetry cycles. This excellent OER activity and stability could be ascribed to the abundant oxygen vacancies and a well-defined hexagonal structure. It is worth noting that this method will offer a facile synthesis of metal hydroxides for generating oxygen vacancy, improving the electrochemical performance of energy storage applications.
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