Precise surface reorganization on iron incorporated cobalt oxides/phosphides using plasma technology for alkaline water/seawater electrolytes

Abstract

Reasonable design of bifunctional catalysts with prominent catalytic activity and excellent stability is regarded as essential and valuable for alkaline seawater electrolysis. Herein, homogenous iron-incorporated cobalt oxides/phosphides nanowires (CoOx/Fe-CoP) were innovatively constructed with oxygen plasma oxidation-induced surface reconfiguration strategy. Benefiting from the abundant homogeneous interface, high intrinsic activity, and fast reaction kinetics, the CoOx/Fe-CoP demands only an ultra-low overpotential of 139 and 267 mV to achieve 100 mA/cm2 for hydrogen evolution reaction and oxygen evolution reaction in 1 M KOH, respectively. Furthermore, the assembled two-electrode configuration requires a cell voltage of 1.73/1.78 V at 100 mA/cm2 with outstanding durability for overall alkaline freshwater/seawater splitting, which is more remarkable than the mature Pt/C||RuO2 pair and many previously reported non-noble electrocatalysts. Hence, this research presents a promising approach to designing and fabricating efficient electrocatalysts by oxygen plasma surface reconstruction engineering toward alkaline freshwater and seawater electrolysis.