Solvent-assisted phase modification of Ni–P material to boost electrocatalytic water splitting and charge storage capacity

Authors

• Anjali Gupta, Pittsburg High School
• Cassia A. Allison, Pittsburg High School
• Anuj Kumar, GLA University, Mathura
• Rishabh Srivastava, Pittsburg State University
• Mina Sim, Pittsburg State University
• Jeffery Horinek, Pittsburg State University
• Wang Lin, Pittsburg State University
• Felipe M. de Souza, Pittsburg State University
• Sanjay R. Mishra, College of Arts & Sciences
• Felio Perez, University of Memphis
• Ram K. Gupta, Pittsburg State University
• Tim Dawsey, Pittsburg State University

Abstract

Due to their redox features, Fe/Ni-phosphides and phosphates could be utilized as multi-functional electrode materials for hydrogen and oxygen evolution processes (HER and OER) and supercapacitors, however, regulation in their geometry and electrical structure for further performance improvement is still challenging. Herein, we developed a solvent-assisted approach to modify the Ni–P material's phase, growing Ni2P, Ni12P5, and Ni(PO3)2 cross-linked nanosheets on Ni-foam using the same precursor and different solvents. When compared to Ni2P and Ni12P5, the Ni(PO3)2 sample showed outstanding activity and endurance towards HER (134 mV overpotential@10 mA/cm² and 112 mV/dec Tafel value) and OER (342 mV overpotential@10 mA/cm² and 78 mV/dec Tafel value), respectively. Moreover, the specific capacitance of the Ni(PO3)2 electrode was found to be 4366 (at 10 mV/s) and 7582 mF/cm² (at 1 mA/cm²). Theoretical calculations showed that the density of states and its distribution across the Fermi level increased in the order of Ni2P < Ni12P5 < Ni(PO3)2 which improved their conductivity and electronic properties, benefiting electrocatalytic HER and OER activity and the charge-storing capacity of Ni(PO3)2.

Publication Title

Journal of Energy Storage

Recommended Citation

Gupta, A., Allison, C., Kumar, A., Srivastava, R., Sim, M., Horinek, J., Lin, W., de Souza, F., Mishra, S., Perez, F., Gupta, R., & Dawsey, T. (2024). Solvent-assisted phase modification of Ni–P material to boost electrocatalytic water splitting and charge storage capacity. Journal of Energy Storage, 75 https://doi.org/10.1016/j.est.2023.109598