Dual-Doping and Synergism toward High-Performance Seawater Electrolysis

Jinfa Chang; Guanzhi Wang; Zhenzhong Yang; Boyang Li; Qi Wang; Ruslan Kuliiev; Nina Orlovskaya; Meng Gu; Yingge Du; Guofeng Wang; Yang Yang

doi:10.1002/adma.202101425

Dual-Doping and Synergism toward High-Performance Seawater Electrolysis

Adv Mater. 2021 Aug;33(33):e2101425. doi: 10.1002/adma.202101425. Epub 2021 Jul 8.

Authors

Jinfa Chang¹, Guanzhi Wang¹, Zhenzhong Yang², Boyang Li³, Qi Wang⁴, Ruslan Kuliiev⁵, Nina Orlovskaya⁵, Meng Gu⁴, Yingge Du², Guofeng Wang³, Yang Yang¹

Affiliations

¹ NanoScience Technology Center, Department of Materials Science and Engineering, Department of Chemistry, Renewable Energy and Chemical Transformation Cluster, University of Central Florida, Orlando, FL, 32826, USA.
² Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
³ Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA, 15261, USA.
⁴ Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China.
⁵ Department of Mechanical and Aerospace Engineering, Renewable Energy and Chemical Transformation Cluster, University of Central Florida, Orlando, FL, 32816, USA.

PMID: 34235791
DOI: 10.1002/adma.202101425

Abstract

Hydrogen (H₂ ) production from direct seawater electrolysis is an economically appealing yet fundamentally and technically challenging approach to harvest clean energy. The current seawater electrolysis technology is significantly hindered by the poor stability and low selectivity of the oxygen evolution reaction (OER) due to the competition with chlorine evolution reaction in practical application. Herein, iron and phosphor dual-doped nickel selenide nanoporous films (Fe,P-NiSe₂ NFs) are rationally designed as bifunctional catalysts for high-efficiency direct seawater electrolysis. The doping of Fe cation increases the selectivity and Faraday efficiency (FE) of the OER. While the doping of P anions improves the electronic conductivity and prevents the dissolution of selenide by forming a passivation layer containing P-O species. The Fe-dopant is identified as the primary active site for the hydrogen evolution reaction, and meanwhile, stimulates the adjacent Ni atoms as active centers for the OER. The experimental analyses and theoretical calculations provide an insightful understanding of the roles of dual-dopants in boosting seawater electrolysis. As a result, a current density of 0.8 A cm^-2 is archived at 1.8 V with high OER selectivity and long-term stability for over 200 h, which surpasses the benchmarking platinum-group-metals-free electrolyzers.

Keywords: activity; dual-doping; nickel selenide; seawater electrolysis; stability.