Bimetallic MnNi-hydroxide electrodeposited on Ni-foam for superior water-splitting and energy storage

Authors

• Rishabh Srivastava, Pittsburg State University
• Shiva Bhardwaj, Pittsburg State University
• Anuj Kumar, GLA University, Mathura
• Alexandra N. Robinson, National Institute of Material Advancement
• Jolaikha Sultana, College of Arts & Sciences
• Sanjay R. Mishra, College of Arts & Sciences
• Felio Perez, University of Memphis
• Ram K. Gupta, National Institute of Material Advancement

Abstract

Electrochemical energy conversion (via water splitting) and storage (via supercapacitors) are emerging strategies for developing the renewable energy sector; nevertheless, the hunt for low-cost and effective electrode material is a bottleneck issue. Herein, a bimetallic manganese nickel hydroxide was electrodeposited on Ni-foam without polymeric binder, followed by calcination to reveal its oxide configuration. As prepared, manganese nickel hydroxide (MnNi-hydroxide) displayed low Oxygen evolution reaction (OER) and Hydrogen evolution reaction (HER) overpotentials of 231 mV and 327 mV at 10 mA/cm² during electrochemical water splitting, along with a superior turnover frequency of 0.12 sec⁻¹ and 0.056 sec⁻¹, respectively. Theoretical investigations revealed an increase in MnNi-hydroxide activity due to synergistic electronic interaction between Mn and Ni. Further, the MnNi-hydroxide, having high specific capacitances of 1174 mF/cm² at 2 mV/s and 308 mF/cm² at 1 mA/cm², demonstrated a retention capacity of 98.9% over 5000 cycles.

Publication Title

International Journal of Hydrogen Energy

Recommended Citation

Srivastava, R., Bhardwaj, S., Kumar, A., Robinson, A., Sultana, J., Mishra, S., Perez, F., & Gupta, R. (2024). Bimetallic MnNi-hydroxide electrodeposited on Ni-foam for superior water-splitting and energy storage. International Journal of Hydrogen Energy, 49, 971-983. https://doi.org/10.1016/j.ijhydene.2023.10.208