Wu C.-WUnnikrishnan BPeriasamy A.PChen I.-W.PTseng Y.-TYang Y.-YLin W.-JHuang C.-CHUAN-TSUNG CHANG2021-08-032021-08-03202021680485https://www.scopus.com/inward/record.uri?eid=2-s2.0-85088898779&doi=10.1021%2facssuschemeng.0c02309&partnerID=40&md5=2fe57a6c185510c8045b5b4115ec4fe6https://scholars.lib.ntu.edu.tw/handle/123456789/575760In this work, we demonstrate a simple electrochemical approach to convert copper foil into a cost-effective and stable cobalt-doped hollow-structured CuBr@CuO electrocatalyst with high surface porosity for oxygen evolution reaction (OER). First, a thin layer of surface copper atoms of the foil was converted to γ-CuBr nanocorals (NCs) by dissolution and in situ deposition in a bromide medium. Then, the CuBr NCs were doped with Co utilizing the high ionic mobility of Cu+ in the γ-CuBr structure through cation exchange and dissolution reactions. During the Co-doping process, the surface γ-CuBr was converted to Cu2O, leading to the formation of CuBr/Co@Cu2O NCs. CuBr/Co@Cu2O NCs were then converted to CuBr/Co@CuO hollow NCs (h-NCs), with high surface roughness and high stability by three linear sweep voltammetry (LSV) scans in O2-saturated KOH solution (0.1 M) over a potential range of 1.2-1.7 V (vs RHE). The h-NC was not formed without Co-doping of γ-CuBr. The as-formed CuBr/Co@CuO h-NCs exhibit an overpotential of 270 mV with a current density of 10 mA cm-2 and a Tafel slope of 66 mV dec-1 for OER as a result of having high electrochemically active surface area and synergistic catalytic Co and CuBr@CuO nanostructures. Copyright ? 2020 American Chemical Society.Cobalt; Copper; Copper oxides; Cost effectiveness; Deposition; Dissolution; Electrocatalysts; Ion exchange; Oxide minerals; Oxygen; Oxygen evolution reaction; Potassium hydroxide; Surface roughness; Cation exchanges; CuO nanostructures; Dissolution reactions; Electrocatalytic activity and stability; Electrochemically active surface areas; In-situ deposition; Linear sweep voltammetry; Oxygen evolution reaction (oer); Bromine compounds[SDGs]SDG6[SDGs]SDG7journal article10.1021/acssuschemeng.0c023092-s2.0-85088898779