γ-FeO(OH) with multiple surface terminations: Intrinsically active for the electrocatalytic oxygen evolution reaction
Laxmikanta Mallick, Anubha Rajput, Mrinal Kanti Adak, Avinava Kundu, Pratigya Choudhary, Biswarup Chakraborty
Abstract
value from the Nyquist plot). Owing to the superior activity of the γ-FeO(OH)@RT/NF, the anode can further be incorporated into an overall water splitting electrolyzer that can operate at a cell potential of 1.68 V. The microscopic characterization provides concrete evidence in support of the polycrystallinity of the γ-FeO(OH)@RT. The superior activity of the γ-FeO(OH)@RT perhaps can be correlated to its polycrystalline nature with more defect edges, the presence of a large exposed surface and random atomic arrangements. The highest degree of multiple surface active terminals (-O, -OH and -Fe) available in this polycrystalline γ-FeO(OH) perhaps makes the catalyst more active compared to the crystalline FeO(OH) analogue with a limited number of surface terminals. From a comparative study with a series of FeO(OH) materials, this work highlights a direct relationship between the surface functionality and the electrochemical activity of the FeO(OH) material.