Ultrafast Formation of Amorphous Bimetallic Hydroxide Films on 3D Conductive Sulfide Nanoarrays for Large-Current-Density Oxygen Evolution Electrocatalysis.

Zou, Xu; Liu, Yipu; Li, Guo-Dong; Wu, Yuanyuan; Liu, Da-Peng; Li, Wang; Li, Hai-Wen; Wang, Dejun et al. · Adv Mater · 2017

basic_science · Level V

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Abstract

Developing nonprecious oxygen evolution electrocatalysts that can work well at large current densities is of primary importance in a viable water-splitting technology. Herein, a facile ultrafast (5 s) synthetic approach is reported that produces a novel, efficient, non-noble metal oxygen-evolution nano-electrocatalyst that is composed of amorphous Ni-Fe bimetallic hydroxide film-coated, nickel foam (NF)-supported, Ni<sub>3</sub> S<sub>2</sub> nanosheet arrays. The composite nanomaterial (denoted as Ni-Fe-OH@Ni<sub>3</sub> S<sub>2</sub> /NF) shows highly efficient electrocatalytic activity toward oxygen evolution reaction (OER) at large current densities, even in the order of 1000 mA cm<sup>-2</sup> . Ni-Fe-OH@Ni<sub>3</sub> S<sub>2</sub> /NF also gives an excellent catalytic stability toward OER both in 1 m KOH solution and in 30 wt% KOH solution. Further experimental results indicate that the effective integration of high catalytic reactivity, high structural stability, and high electronic conductivity into a single material system makes Ni-Fe-OH@Ni<sub>3</sub> S<sub>2</sub> /NF a remarkable catalytic ability for OER at large current densities.