A Dendritic Nanostructured Copper Oxide Electrocatalyst for the Oxygen Evolution Reaction

Abstract

To use water as the source of electrons for proton or CO reduction within electrocatalytic devices, catalysts are required for facilitating the proton-coupled multi-electron oxygen evolution reaction (OER, 2 H O→O +4 H +4 e ). These catalysts, ideally based on cheap and earth abundant metals, have to display high activity at low overpotential and good stability and selectivity. While numerous examples of Co, Mn, and Ni catalysts were recently reported for water oxidation, only few examples were reported using copper, despite promising efficiencies. A rationally designed nanostructured copper/copper oxide electrocatalyst for OER is presented. This material derives from conductive copper foam passivated by a copper oxide layer and further nanostructured by electrodeposition of CuO nanoparticles. The generated electrodes are highly efficient for catalyzing selective water oxidation to dioxygen with an overpotential of 290 mV at 10 mA cm in 1 m NaOH solution.

Cu3P/CuO Core‐Shell Nanorod Arrays as High‐Performance Electrocatalysts for Water Oxidation

“…However, the intensities of the Cu 2p peaks arising from Cu 3 P were significantly decreased after electrochemical oxidation, along with the appearance of two new peaks for Cu 2p at 933.8 (2p 3/2 ) and 953.8 eV (2p 1/2 ) and the disappearance of the oxidized Cu−P signals at 934.5 (Cu 2p 3/2 ) and 954.7 eV (Cu 2p 1/2 ). These observations in combination with the appearance of O1s signal (Figure c) at 529.4 eV suggest the presence of CuO as the dominant surface species ,,. The Cu−O vibration bands at 298, 346 and 631 cm −1 in Raman spectrum in Figure d also verify the formation of CuO layer .…”

“…The porous core‐shell nanostructures possess high specific surface area and accelerate the mass transfer of electrolyte, greatly boosting the OER kinetics of copper oxide. In Mougel's work, a layer of CuO nanoparticles was further deposited on the surface of Cu−Cu 2 O to benefit the OER performance . However, the resulting electrode suffered from low stability in highly basic media such as 1.0 M NaOH solution.…”

Heterostructures Composed of N‐Doped Carbon Nanotubes Encapsulating Cobalt and β‐Mo2C Nanoparticles as Bifunctional Electrodes for Water Splitting

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Herein, we demonstrate the use of heterostructures comprised of Co/b-Mo 2 C@N-CNT hybrids for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in an alkaline electrolyte.T he Co can not only create awell-defined heterointerface with b-Mo 2 Cbut also overcomes the poor OER activity of b-Mo 2 C, thus leading to enhanced electrocatalytic activity for HER and OER. [2,3] However,t he low abundance and high cost of noble-metal catalysts significantly hinder their large-scale commercialization. [1] Thee lectrolysis of water involves two half reactions: the cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER), for which highly efficient electrocatalysts,s uch as Pt for the HER and IrO 2 for the OER, are usually required.

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“…As control experiments,t wo samples of Co@N-CNTs and Mo 2 C@N-CNTs were prepared as well, following asimilar method to that used to prepare the Co/b-Mo 2 C@N-CNTs,b ut without using the Mo salt or Co salt precursor,r espectively.T he morphology of as-prepared samples was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). [2] The XRD pattern of Co@N-CNTs and Mo 2 C@N-CNTs corresponds to metallic Co (JCPDS 15-0806) and Mo 2 C( JCPDS 26-1076), respectively (see Figure S1). 18 nm in diameter) and Co (ca.…”

Hollow Carbon@NiCo2O4 Core–Shell Microspheres for Efficient Electrocatalytic Oxygen Evolution

“…For C@NiCo 2 O 4 HSs, the combination of the 1D nanosheet structure (NiCo 2 O 4 ) and the unique 3D hollow microsphere structure provided a large active surface area with a great number of accessible active sites, which can facilitate the diffusion of electrolytes and the release of gas products. In addition, the hollow carbon core support induces a favorable electron pathway between the catalytic active metal oxide and the electrode substrate (NF) during the electrochemical process, which was confirmed by the enhanced electrical conductivity of C@NiCo 2 O 4 /NF, as demonstrated by EIS (Figure d) …”