Fine-tuning the water oxidation performance of hierarchical CoO nanostructures prepared from different cobalt precursors

• Published in: Sustainable energy & fuels 2021-02, Vol.5 (4), p.112-1128
• Main Authors: Bodhankar, Pradnya M, Chunduri, Avani, Patel, Nainesh, Dhawale, Dattatray S, Vinu, Ajayan, Aljohani, Hind, Sarawade, Pradip B
• Format: Article
• ISSN: 2398-4902
• DOI: 10.1039/d0se01711f

The design of efficient and low-cost catalysts for water oxidation with superior electrochemical performance is of great importance. Herein, we report on the fine-tuning of water oxidation performance using solvothermal fabricated hierarchical nanostructured Co 3 O 4 catalysts obtained from three different cobalt precursors. The prepared hierarchical Co 3 O 4 nanostructured catalysts were intensively analyzed for their textural properties and surface chemistry, such as shape, size, phase and surface area. The water oxidation performance of all three catalysts through the oxygen evolution reaction (OER) has been investigated. In alkaline 1 M KOH aqueous solution, the ultrathin hierarchical Co 3 O 4 -S nanosheet array catalyst exhibits significantly higher activity during water oxidation, with a low overpotential of 330 mV vs. RHE at a benchmarking current density of 10 mA cm −2 for OER in comparison with Co 3 O 4 -Ac and Co 3 O 4 -N, which outperforms a commercial RuO 2 electrocatalyst, and it remains stable for many hours. Benefiting from its unique ultrathin architecture, hierarchical and nanostructured Co 3 O 4 -S is endowed with a large number of active sites and a rapid charge transfer process, resulting in better water oxidation performance. Three different hierarchical nanostructured Co 3 O 4 catalysts are prepared by simple alteration of the precursor. The Co 3 O 4 -S catalyst shows superior water oxidation activity due to its improved charge transfer ability and high specific surface area.