Decorated by Cu nanoparticles CoS2 nanoneedle array for effective water oxidation electrocatalysis

Abstract Developing active, stable and cost-effective transition metal electrocatalysts for increasing the rate of the oxygen evolution reaction (OER) is crucial for renewable energy conversion, but still remains challenging. In this communication, we report a novel Cu-nanoparticle decorated CoS2 nanoneedle array on Ti mesh (Cu@CoS2/TM) as an efficient electrocatalyst for alkaline water oxidation. Benefiting from a large active surface area and a strong interfacial interaction between Cu and CoS2, Cu@CoS2/TM exhibits excellent OER performance in alkaline media with only a small overpotential of 277 mV to deliver 50 mA cm−2. This value is 62 mV less than that of CoS2/TM. Cu@CoS2/TM achieves a high turnover rate of 0.25 mol O2 s−1 at 400 mV, which is approximately 1.7 times higher than that of CoS2/TM. Notably, Cu@CoS2/TM also demonstrates superior long-term electrochemical stability.