Promotion of the oxygen evolution performance of Ni-Fe layered hydroxides via the introduction of a proton-transfer mediator anion

Developing efficient catalysts with high durability and activity for the oxygen evolution reaction (OER) is imperative for sustainable energy conversion technologies, including hydrogen generation and CO2 reduction, as well as other electrochemical energy storage systems. To this end, a comprehensive understanding of the mechanism for the water oxidation reaction is vital. Herein, a surfactant, nonafluoro-1-butanesulfonate (FBS), was introduced into Ni-Fe layered double hydroxide (NiFe-FBS/CFP) via electrochemical deposition on the surface of a carbon fiber paper (CFP) substrate. The as-prepared NiFe-FBS/CFP electrode exhibited excellent catalytic activities for OER compared to the Ni-Fe layered double hydroxide based electrode (NiFe-LDH/CFP), an excellent stability of 15 h, and an ultralow Tafel slope of 25.8 mV dec(-1). Furthermore, by combining the results of pH-dependent kinetics investigations, chemical probing, proton inventory studies, and isotopic and atom-protontransfer measurements, it was observed that a proton-transfer process controls the reaction rates of both the NiFe-LDH and NiFe-FBS catalysts, and the residual sulfonate groups serve as proton transfer mediator to accelerate the proton transfer rate.

Automated summary

This study investigated the performance of an oxygen evolution reaction (OER) catalyst based on surfactant-modified Ni-Fe layered double hydroxide. The modified catalyst showed excellent catalytic activity and stability in OER, with proton transfer process controlling the reaction rates of the catalysts.