Issue 37, 2023

Heterointerface engineering of cobalt molybdenum suboxide for overall water splitting

Abstract

Highly active and earth-abundant electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are of great significance for sustainable hydrogen generation through alkaline water electrolysis. Here, with an aim to enhance the bifunctional electrocatalytic activity of cobalt molybdate towards overall water splitting, we demonstrate a simple method involving the modulation of the cobalt to molybdenum ratio and creation of phase-modulated heterointerfaces. Samples with varying Co/Mo molar ratios are obtained via a microwave-assisted synthesis method using appropriate starting precursors. The synthesis conditions are modified to create a heterointerface involving multiple phases of cobalt molybdenum suboxides (CoO/CoMoO3/Co2Mo3O8) supported on Ni foam (NF). Detailed electrochemical studies reveal that modulating the composition and hence the interface can tweak the bifunctional electrocatalytic activity of the material for HER and OER and thus improve the overall water splitting efficiency with very high durability over 500 h. To further evaluate the practical applicability of the studied catalyst in water splitting, an alkaline electrolyser is fabricated with the optimized cobalt molybdenum suboxide material (CMO-1.25) as a bifunctional electrocatalyst. A current density of 220 mA cm−2 @1.6 V and 670 mA cm−2 @1.8 V was obtained, and the device showed very good long-term durability.

Graphical abstract: Heterointerface engineering of cobalt molybdenum suboxide for overall water splitting

Supplementary files

Article information

Article type
Paper
Submitted
26 May 2023
Accepted
24 Aug 2023
First published
06 Sep 2023
This article is Open Access
Creative Commons BY license

Nanoscale, 2023,15, 15219-15229

Heterointerface engineering of cobalt molybdenum suboxide for overall water splitting

R. Nadarajan, A. V. Gopinathan, N. P. Dileep, A. S. Sidharthan and M. M. Shaijumon, Nanoscale, 2023, 15, 15219 DOI: 10.1039/D3NR02458J

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