Anion insertion enhanced electrodeposition of robust metal hydroxide/oxide electrodes for oxygen evolution.

Yan, Zhenhua; Sun, Hongming; Chen, Xiang; Liu, Huanhuan; Zhao, Yaran; Li, Haixia; Xie, Wei; Cheng, Fangyi et al. · Nat Commun · 2018

basic_science · Level V

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Abstract

Electrochemical deposition is a facile strategy to prepare functional materials but suffers from limitation in thin films and uncontrollable interface engineering. Here we report a universal electrosynthesis of metal hydroxides/oxides on varied substrates via reduction of oxyacid anions. On graphitic substrates, we find that the insertion of nitrate ion in graphene layers significantly enhances the electrodeposit-support interface, resulting in high mass loading and super hydrophilic/aerophobic properties. For the electrocatalytic oxygen evolution reaction, the nanocrystalline cerium dioxide and amorphous nickel hydroxide co-electrodeposited on graphite exhibits low overpotential (177 mV@10 mA cm-2) and sustains long-term durability (over 300 h) at a large current density of 1000 mA cm-2. In situ Raman and operando X-ray diffraction unravel that the integration of cerium promotes the formation of electrocatalytically active gamma-phase nickel oxyhydroxide with exposed (003) facets. Therefore, combining anion intercalation with cathodic electrodeposition allows building robust electrodes with high electrochemical performance.