Enhanced electrolytic generation of oxygen gas at binary nickel oxide–cobalt oxide nanoparticle-modified electrodes

Abstract

This study addresses the enhancement of the oxygen evolution reaction (OER) on glassy carbon, Au, and Pt electrodes modified with binary catalysts composed of nickel oxide nanoparticles (nano-NiO x ) and cobalt oxide nanoparticles (nano-CoO x ). Binary NiO x /CoO x -modified electrodes (with NiO x initially deposited) show a high catalytic activity and a marked stability which far exceeds that obtained at the individual oxide-modified electrodes. This enhancement is demonstrated by a marked negative shift (more than ca. 600 mV) in the onset potential of the OER compared to that obtained at the unmodified electrodes. The modified electrodes show a significantly higher long-term stability, over a period of 5 h of continuous electrolysis, without any significant loss of activity towards the OER in alkaline medium. The influence of the solution pH, the loading level, and sequence of deposition of each oxide on the electrocatalytic activity of the modified electrodes is addressed with an aim to maximize the catalytic activity of the modified electrodes towards the OER. SEM imaging is used to disclose the size and morphology of the fabricated nano-NiO x and nano-CoO x binary catalysts at the electrode surface.

NiCo2O4 3 dimensional nanosheet as effective and robust catalyst for oxygen evolution reaction

“…4). 13,25 However, the performance of CP for the OER is very low; specically the current is still lower than 10 mA cm À2 even with the overpotential of 475 mV. An overpotential as low as 360 mV was needed to reach a current density of 10 mA cm À2 , and further increasing the potential causes a steep rise of anode current, suggesting NiCo 2 O 4 nanosheet on conductive support acts as a high-performance 3D anode for oxygen evolution.…”

“…For this, water electrolysis plays a fundamental role in the development of a sustainable energy system. [13][14][15][16][17] For example, cobalt-nickel oxides particles electrodeposited on glass carbon electrode displayed a high activity and stability for the OER with an overpotential of 450 mV to reach 20 mA cm À2 ; 13 McCrory et al benchmarked different OER catalysts and found that the overpotential of 380 mV at 10 mA cm À2 for CoNiO x was statistically less than that of single metal oxide; 14 Alexander Eychmüller et al developed a class of nickel cobalt oxide hollow nanosponges and found that compared with NiO and Co 3 O 4 , nickel cobalt oxide hollow nanosponges exhibit the highest catalytic activity towards the OER with the overpotential of 362 mV at 10 mA cm À2 . 9 Thus considerable research effort has been devoted to the development of anode materials with the aim of achieving highest efficiency of the OER at the lowest over potential.…”

Three-dimensional porous carbon nanofiber networks decorated with cobalt-based nanoparticles: A robust electrocatalyst for efficient water oxidation

“…Several heterogeneous and homogeneous cobalt-based OER catalysts have been recently proposed [26][27][28][29][30]. Despite these achievements, homogeneous incorporation of cobalt components into a 3D conductive framework remains challenging.…”

Back‐Illuminated Si‐Based Photoanode with Nickel Cobalt Oxide Catalytic Protection Layer

“…To date, many research groups have demonstrated the catalytic behavior of elemental nickel or cobalt oxides, [16,[19][20][21][22][23][24] whereas a relatively small number of studies report the electrocatalytic activity of binary nickel cobalt oxides. [9][10][11] In the present work, we demonstrate the time-dependent behavior of the OER kinetics of NiCoO x thin films in 1 m KOH (pH 14) electrolyte.…”