Three-dimensional porous CoNiO 2 @reduced graphene oxide nanosheet arrays/nickel foam as a highly efficient bifunctional
- PDF / 5,289,227 Bytes
- 13 Pages / 595.276 x 790.866 pts Page_size
- 29 Downloads / 220 Views
Tungsten https://doi.org/10.1007/s42864-020-00065-3
www.springer.com/42864
ORIGINAL PAPER
Three‑dimensional porous CoNiO2@reduced graphene oxide nanosheet arrays/nickel foam as a highly efficient bifunctional electrocatalyst for overall water splitting Zhi‑Yi Pan1,2 · Zheng Tang3 · Yong‑Zhong Zhan1,2 · Dan Sun3 Received: 17 August 2020 / Revised: 22 September 2020 / Accepted: 28 September 2020 © The Nonferrous Metals Society of China 2020
Abstract It is crucial to develop high-performance and cost-effective bifunctional electrocatalysts for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) toward overall water splitting. Herein, a unique heterostructure of reduced graphene oxide (rGO) and C oNiO2 nanosheets directly grown on nickel foam (NF) were successfully fabricated and applied as a kind of highly efficient bifunctional electrocatalyst. The optimum C oNiO2@rGO/NF electrode exhibits excellent electrocatalytic OER performance with an overpotential of only 272 mV to drive a current density of 100 mA·cm−2, and HER performance with an overpotential of 126 mV to achieve a current density of 10 mA·cm−2. Meanwhile, the electrodes also display outstanding long-term stability for OER and HER with negligible activity and morphology degradation after at least 40 h testing. Furthermore, when employed as both cathode and anode for overall water splitting, CoNiO2@rGO/NF electrode only requires 1.56 V at 10 mA·cm−2 and operates stably for over 40 h, which is among the best performing Co-based and Ni-based non-precious metal electrocatalysts. Detailed characterizations reveal that the extraordinary electrocatalytic performance should be attributed to the synergistic effect of the unique heterostructure of CoNiO2 nanosheets and rGO for increasing the electrode conductivity and integrity, ultrasmall primary particle size for providing larger electrode/electrolyte contact area and abundant active sites, and three-dimensional (3D) conductive networks for facilitating the electrochemical reaction. Keywords CoNiO2@reduced graphene oxide arrays · Bifunctional electrocatalyst · Oxygen evolution reaction · Hydrogen evolution reaction · Water splitting
1 Introduction Electronic supplementary material The online version of this article (https://doi.org/10.1007/s42864-020-00065-3) contains supplementary material, which is available to authorized users. * Yong‑Zhong Zhan [email protected] * Dan Sun [email protected] 1
School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China
2
Collaborative Innovation Center of Sustainable Energy Materials, School of Resources, Environment and Materials, Guangxi Key Laboratory of Electrochemical Energy Materials, Guangxi University, Nanning 530004, China
3
College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
The exploitation of renewable and clean energy is significant to solve the severe energy crisis and environmental pollution problems caused by the ex
Data Loading...
