Enhanced catalytic performance of ZnO-CoOx electrode generated from electrochemical corrosion of Co-Zn alloy for oxygen evolution reaction

In this work, the ZnO-CoOx catalyst has been prepared by co-electrodeposition and electrochemical corrosion of Co-Zn alloy on modified substrates. Benefiting from sacrifice of zinc and the transformation of cobalt, the constructed ZnO-CoOx catalysts possess larger electrochemically active surface area (ECSA) and sufficient exposure of active cites for water oxidation. Accordingly, the electrochemical double-layer capacitance (Cdl) of ZnO-CoOx catalysts is proved to be 106.9 mF cm (2), which is much larger than that of the corresponding zinc sacrifice-free sample (Co-NZ/CPEC, C-dl = 13.0 mF cm (2)). Moreover, the substrate (denoted as CPEC) is fabricated on copper plate by electrochemical corrosion and chemical reduction to get better wettability, which makes the substrate load catalysts more easily and tightly. Besides, the insitu growth of active materials greatly facilitates the electron transfer efficiency between the substrate and catalysts. Thus, the prepared ZnO-CoOx/CPEC electrode shows enhanced OER activity (eta(j) = 10 m A cm (2) = 276 mV) and desirable durability (current retention >92% after electrolysis of 24 h) compared with the conventional Co-based catalysts. (C) 2016 Elsevier Ltd. All rights reserved.