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Efficient Oxygen Evolution and Gas Bubble Release Achieved by a Low Gas Bubble Adhesive Iron–Nickel Vanadate Electrocatalyst
Author(s) -
Dastafkan Kamran,
Meyer Quentin,
Chen Xianjue,
Zhao Chuan
Publication year - 2020
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.202002412
Subject(s) - vanadate , oxygen evolution , catalysis , chemical engineering , materials science , adsorption , nickel , electrocatalyst , electrochemistry , wetting , bubble , electrolysis of water , inorganic chemistry , electrolysis , chemistry , electrode , metallurgy , composite material , organic chemistry , electrolyte , engineering , parallel computing , computer science
Surface chemistry is a pivotal prerequisite besides catalyst composition toward advanced water electrolysis. Here, an evident enhancement of the oxygen evolution reaction (OER) is demonstrated on a vanadate‐modified iron–nickel catalyst synthesized by a successive ionic layer adsorption and reaction method, which demonstrates ultralow overpotentials of 274 and 310 mV for delivering large current densities of 100 and 400 mA cm −2 , respectively, in 1 m KOH, where vigorous gas bubble evolution occurs. Vanadate modification augments the OER activity by i) increasing the electrochemical surface area and intrinsic activity of the active sites, ii) having an electronic interplay with Fe and Ni catalytic centers, and iii) inducing a high surface wettability and a low‐gas bubble‐adhesion for accelerated mass transport and gas bubble dissipation at large current densities. Ex situ and operando Raman study reveals the structural evolution of β‐NiOOH and γ‐FeOOH phases during the OER through vanadate‐active site synergistic interactions. Operando dynamic specific resistance measurement evidences an accelerated gas bubble dissipation by a significant decrease in the variation of the interfacial resistance during the OER for the vanadate‐modified surface. Achievement of a high catalytic turnover of 0.12 s −1 suggests metallic oxo‐anion modification as a versatile catalyst design strategy for advanced water oxidation.