Spinel of Nickel-Cobalt Oxide with Rod-Like Architecture as Electrocatalyst for Oxygen Evolution Reaction

Abstract

The renewable energy technologies require electrocatalysts for reactions, such as the oxygen and/or hydrogen evolution reaction (OER/HER). They are complex electrochemical reactions that take place through the direct transfer of electrons. However, mostly they have high over-potentials and slow kinetics, that is why they require electrocatalysts to lower the over-potential of the reactions and enhance the reaction rate. The commercially used catalysts (e.g., ruthenium nanoparticles—Ru, iridium nanoparticles—Ir, and their oxides: RuO2, IrO2, platinum—Pt) contain metals that have poor stability, and are not economically worthwhile for widespread application. Here, we propose the spinel structure of nickel-cobalt oxide (NiCo2O4) fabricated to serve as electrocatalyst for OER. These structures were obtained by a facile two-step method: (1) One-pot solvothermal reaction and subsequently (2) pyrolysis or carbonization, respectively. This material exhibits novel rod-like morphology formed by tiny spheres. The presence of transition metal particles such as Co and Ni due to their conductivity and electron configurations provides a great number of active sites, which brings superior electrochemical performance in oxygen evolution and good stability in long-term tests. Therefore, it is believed that we propose interesting low-cost material that can act as a super stable catalyst in OER.

Binary Co9S8–NiCo2S4 anchored on N-doped rGO backbone as an efficient bifunctional and durable hetero-catalyst for overall water-splitting in alkaline medium

“…The intense Raman peaks at 682.7 cm −1 and 650.6 cm −1 correspond to the A 1g mode of Co 3 O 4 and Ni–Co–O of NiCo 2 O 4 . 49–52…”

The role of Preparation Technique on the Structure, Electrical Properties of CoxZn1-xFe2O4 and its Electrocatalytic Effect on Hydrogen Evolution Reaction

“…As observed from the voltammgrams, the presence of Co increases the current of both the anodic and cathodic branch. For 0.8Co content, an increase in the cathodic current density due to the hydrogen evolution reaction was observed with the oxide reduction followed by H + intercalation and the corresponding anodic current peak due to the de-intercalation process 33 . Also, as the Co content increases in the sample, the potential of the hydrogen evolution shifts to more positive.…”

“…In recent years, different materials was used to catalyse the water splitting in both acidic and alkaline media [29][30][31][32] , However spinel oxides have attracted an interest in catalysing the oxygen evolution reaction (OER) due to their efficiency and cost-effectiveness 2,33,34 . Nowadays, finding low cost electrode materials with good electrical and kinetic properties was the main aim.…”

Exfoliated graphite with spinel oxide as an effective hybrid electrocatalyst for water splitting

“…3,7,10 Transition metal-based spinel-type materials have rapidly become have emerged as promising and highly efficient active materials for potential electrochemical applications due to their numerous advantages such as low prices, abundant resources, and environmental friendliness. [11][12][13] Among the wide range of compounds, spinels containing cobalt, nickel or molybdenum are of particular interest as high-performance oxygen evolution reaction (OER) catalysts. 14,15 One example of the use of bimetallic oxides for HER and OER is NiCo 2 O 4 .…”

“…16 The presence of transition metal particles such as cobalt and nickel, due to their conductivity and electron congurations, provides a large number of active sites and excellent electrochemical performance in the oxygen evolution reaction. 12,17 However, other bimetallic oxides, which will also be characterized by good electrocatalytic activity, should also be searched. Recently, electrode materials of spinel-type compounds containing cobalt and manganese have been intensively studied as a very promising electrocatalyst.…”