Electrodeposited Ni_xCo_3−xO₄nanostructured films as bifunctional oxygen electrocatalysts

Abstract

Nanostructured Ni(x)Co(3-x)O4 films serve as effective electrocatalysts for both the oxygen reduction and oxygen evolution reactions in alkaline electrolyte.

Engineering Pyrite-Type Bimetallic Ni-Doped CoS2 Nanoneedle Arrays over a Wide Compositional Range for Enhanced Oxygen and Hydrogen Electrocatalysis with Flexible Property

“…Moreover, as the Ni-doping content increases in Ni-Co precursors, the corresponding nanoneedle becomes shorter, narrower and rougher (Figure 2a-c), which can be attributed to the doping effect on the size control of nanocrystals [47]. This is also echoed with previous phenomena, namely, the grain sizes slightly decreased with an increasing concentration of metallic Ni element in Ni-Co-based nanocomposites [44,48]. After the sulfidation treatment, the nanoneedle arrays were well-retained in the final Ni x Co 1−x S 2 , with the appearance of porous nanostructures and increased surface roughness (Figure 2d-f).…”

“…We next considered the effect from the electronic structure. On one hand, conductivity investigations on a series of spinel Ni x Co 3−x O 4 (0 ≤ x ≤ 1) revealed that the activation energy almost disappears completely at a modest x value, rendering the oxide with a semi-metallic nature [48,55]. On the other hand, the larger crystallite size may also result in a more conductive sample [48].…”

“…On one hand, conductivity investigations on a series of spinel Ni x Co 3−x O 4 (0 ≤ x ≤ 1) revealed that the activation energy almost disappears completely at a modest x value, rendering the oxide with a semi-metallic nature [48,55]. On the other hand, the larger crystallite size may also result in a more conductive sample [48]. Thus, in our study, the Ni 0.33 Co 0.67 S 2 sample may have possessed the highest electrical conductivity in the Ni x Co 1−x S 2 series, which facilitated the electron transfer during the catalytic reaction and allowed the superior catalytic activity toward both HER and OER.…”

First row transition metal catalysts for solar-driven water oxidation produced by electrodeposition

“…Lambert and co-workers recently communicated a Ni x Co 3-x O 4 mixed oxide material with activity for both the OER and its reverse reaction, the reduction of oxygen to water (the "oxygen reduction reaction", or ORR). 89 Catalysts were electrodeposited galvanostatically from solutions containing cobalt(II) nitrate and nickel(II) nitrate in various ratios and then annealed at 573 K in air. Grazing angle X-ray diffraction spectra confirmed the formation of spinel phase NiCo 2 O 4 -type materials in all cases.…”

Insights into the spontaneous formation of hybrid PdOx/PEDOT films: electroless deposition and oxygen reduction activity

“…16 The resulting oxidized PEDOT lm (doped with perchlorate anions) was electrochemically reduced at constant potential in the CH 3 The preparation of the hybrid PdO x /PEDOT lm was reproduced on Ti/Pt quartz crystal electrodes monitored by a Quartz Crystal Microbalance (QCM) to understand the mass change and doping/de-doping behaviour of the PEDOT lm during the electrochemical reduction and Pd deposition steps. Anodic electropolymerization of PEDOT results in a linear increase in lm mass at the electrode surface, with an average deposition rate of 0.98 AE 0.03 mg cm À2 s À1 (Fig.…”