Nanoporous CuCo2O4 nanosheets as a highly efficient bifunctional electrode for supercapacitors and water oxidation catalysis

• Published in: Applied surface science 2019-03, Vol.470, p.360-367
• Main Authors: Pawar, Sambhaji M., Pawar, Bharati S., Babar, Pravin T., Ahmed, Abu Talha Aqueel, Chavan, Harish S., Jo, Yongcheol, Cho, Sangeun, Kim, Jongmin, Hou, Bo, Inamdar, Akbar I., Cha, SeungNam, Kim, Jin Hyeok, Kim, Tae Geun, Kim, Hyungsang, Im, Hyunsik
• Format: Article
• Language: English
• Subjects: CuCo2O4 nanosheets; Electrocatalyst; Electrodeposition; Oxygen evolution reaction; Supercapacitor
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2018.11.151

[Display omitted] •Ultrathin nanoporous CuCo2O4 nanosheets electrode synthesized by electrodeposition.•High specific capacitance and good cycling stability were obtained.•Highly efficient OER electrocatalyst with an overpotential of 260 mV at 20 mA/cm2.•Excellent long-term electrochemical durability. Efficient and low‐cost multifunctional electrodes play a key role in improving the performance of energy conversion and storage devices. In this study, ultrathin nanoporous CuCo2O4 nanosheets are synthesized on a nickel foam substrate using electrodeposition followed by air annealing. The CuCo2O4 nanosheet electrode exhibits a high specific capacitance of 1473 F g─1 at 1 A g─1 with a capacity retention of ∼93% after 5000 cycles in 3 M KOH solution. It also works well as an efficient oxygen evolution reaction electrocatalyst, demonstrating an overpotential of 260 mV at 20 mA cm─2 with a Tafel slope of ∼64 mV dec─1. in 1 M KOH solution, which is the lowest reported among other copper-cobalt based transition metal oxide catalysts. The catalyst is very stable at >20 mA cm─2 for more than 25 h. The superior electrochemical performance of the CuCo2O4 nanosheet electrode is due to the synergetic effect of the direct growth of 2D nanosheet structure and a large electrochemically active surface area associated with nanopores on the CuCo2O4 nanosheet surface.