Electrochemically activated Ni@Ni(OH)2 heterostructure as efficient hydrogen evolution reaction electrocatalyst for anion exchange membrane water electrolysis. (June 2022)

• Record Type: Journal Article
• Authors: Guo, W.; Kim, J.; Kim, H.; Hong, S.; Kim, H.; Kim, S.Y.; Ahn, S.H.
• Is Part Of: Materials today chemistry. Volume 24(2022)
• Publication Date: 2022-06
• Subjects: Heterostructure catalyst -- Electrodeposition -- Electrochemical activation -- Hydrogen production -- Anion exchange membrane water electrolyzer; Chemistry -- Periodicals; Materials -- Research -- Periodicals; Materials science -- Periodicals; Chemistry; Materials -- Research; Electronic journals; Periodicals; 660.282
• DOI: 10.1016/j.mtchem.2022.100994
• Languages: English
• ISSNs: 2468-5194

Abstract

Abstract: Efficient and cost-effective catalysts are vital for sustainable hydrogen production via water electrolysis. In this study, we propose a facile method of fabricating a Ni@Ni(OH)2 heterostructure catalyst on a Ti paper substrate by combining electrodeposition and subsequent electrochemical activation. Detailed characterization and analysis revealed the formation of Ni (oxy)hydroxides. Ni@Ni(OH)2 underwent surface reconstruction, resulting in the formation of abundant heterojunctions and electron modulation during electrochemical activation, which substantially increased the exposed surface area facilitating the adsorption of intermediates during the hydrogen evolution reaction (HER). Thus, the resulting activated Ni@Ni(OH)2 /Ti electrode exhibited significantly improved HER activity in the half-cell test, reaching a current density of −10 mA/cm 2 at an overpotential of 58 mV with a Tafel slope of 83 mV/dec. When applied to anion exchange membrane water electrolysis, a single cell comprising an Ni@Ni(OH)2 /Ti cathode and commercial IrO2 /CP anode exhibited a maximum current density of 1.00 A/cm 2 at a potential of 2.0 Vcell, demonstrating superior performance to commercial Pt/C electrodes in the high-current-density region above 2.0 A/cm 2 . Graphical abstract: Image 1 Highlights: Ni@Ni(OH)2 /Ti was fabricated by electrodeposition and subsequent electrochemical activation. Ni@Ni(OH)2 /Ti with activation exhibited excellent HER performance with a low overpotential of 54 mV at −10 mA/cm 2 . The AEMWE single cell applying Ni@Ni(OH)2 /Ti as the cathode showed high cell performance of 1.00 A/cm 2 at 2.0 Vcell .