Polyoxometallic chemistry towards all-in-one layered double hydroxides for boosting oxygen evolution electrocatalysis

Abstract Nickel-iron based layered double hydroxides (NiFe LDH) have attracted tremendous research and industrial interests for oxygen evolution reaction electrocatalysis (OER). However, methodologies on simultaneous multi-regulations remain scarce. Herein, we report a versatile polyoxometallic acids (POMs) etching approach for ingeniously designing NiFe LDH, including morphological nanolayers tailoring, reconfiguration of Fe3+ and α-Ni(OH)2 active species, creating multiple vacancies of Ni, Fe and O and manufacturing interlayered POM polyanionic clusters as surface kinetic accelerators. Our experimental and theoretical data reveal that the key influencing factors are simultaneously controlled, resulting in synergistical enhancement with electrocatalytic OER activity of η10 = 206 mV, stability (negligible change of η500 for 24 h), and turnover frequency value (TOFFe, mol) of 2.03 s− 1. To elucidate the evolution, we derive an empirical formula to quantitatively identifying the key performance-determining factors, coinciding with the work and most of literature data. The expression offers an opportunity for first and fast reliability on materials screening. Moreover, the electrocatalyst is further produced on a large scale with low cost and high performance, demonstrating its feasibility of promising configuration of NiFe LDH-PMo12(+) ‖ Ni@NiFe LDH(-) for practical anion-exchange membrane (AEM)-electrode-stack cells water electrolysis.