Cobalt-Iron Oxide Nanoarrays Supported on Carbon Fiber Paper with High Stability for Electrochemical Oxygen Evolution at Large Current Densities

Abstract

Here, we demonstrate that nonprecious CoFe-based oxide nanoarrays exhibit excellent electrocatalytic activity and superior stability for electrochemical oxygen evolution reaction (OER) at large current densities (>500 mA cm–2). Carbon fiber paper (CFP) with three-dimensional macroporous structure, excellent corrosion resistance, and high electrical properties is used as the support material to prevent surface passivation during the long-term process of OER. Through a facile method of hydrothermal synthesis and thermal treatment, vertically aligned arrays of spinel Co x Fe3–x O4 nanostructures are homogeneously grown on CFP. The morphology and the Fe-doping content of the CoFe oxide nanoarrays can be controlled by the Fe3+ concentration in the precursor solution. The arrays of CoFe oxide nanosheets (NSs) grown on CFP (Co2.3Fe0.7O4-NSs/CFP) deliver lower Tafel slope (34.3 mV dec–1) than CoFe oxide nanowire (NW) arrays grown on CFP (Co2.7Fe0.3O4-NWs/CFP) in alkaline solution, owing to higher Fe-doping content and larger effective specific surface area. The Co2.3Fe0.7O4-NSs/CFP electrode exhibits excellent stability for OER at large current densities in alkaline solution. Moreover, the morphology and structure of CoFeO nanoarrays are well preserved after long-term testing, indicating the high stability for OER.

Fe‐Doped CoP Flower‐Like Microstructure on Carbon Membrane as Integrated Electrode with Enhanced Sodium Ion Storage

“…The Fe ion could modulate the surface energy of the Fe-Cos pecies precursor.T hereby,t he morphologyo ft he precursor changed from nanoneedlest on anoflakes after the doping of Fe 3 + in the aqueous solutiond uring the hydrothermalp rocess. [27] This typical hydrothermal process is similar to those reported previously. [28,29] Then, the Fe-Cos pecies precursor and Co species precursor supported on the CM were treated by in situ phosphorization with NaH 2 PO 2 as the phosphorus source.…”

Recent developments in electrochemical sensors for detecting hydrazine with different modified electrodes

“…Moreover, sensitivity of the measurements in the electro-analytical utilizations would be determined by very little alterations in the surface features. [39][40][41][42] Usually, the modied surfaces lead to the cases below:…”

Laser‐Ablation‐Produced Cobalt Nickel Phosphate with High‐Valence Nickel Ions as an Active Catalyst for the Oxygen Evolution Reaction

“…[21] To furtherb oost the performance of phosphates, elemental doping [22] or novels tructures have been engineered. [23,24] Moreover,n on-noblet ransition-metal compounds, such as Ni [25,26] and Co, [27,28] show particularp otential as OER catalysts due to their abundance in the earth, better conductivity,a nd great electrochemical stability. [29] Herein, we preparedc obalt-doped nickel phosphate (denoted as CoNi-PO 4 (L)) through rapid oxidation by nanosecond-pulsed laser irradiation of Co-dopedN i 2 P( gained by electroplatingp rocess, denoted as CoNi 2 P) in deionized water.F or comparison, the CoNi 2 Pw as electrochemically oxidized in neutralm edia of 1 m phosphate buffer solution to obtainedt he phosphated enoted as CoNiPO 4 (E).…”