Development of high-efficiency alkaline OER electrodes for hybrid acid-alkali electrolytic H generation.

The development of high-efficiency oxygen evolution reaction (OER) electrocatalysts is of great importance for electrolytic H generation. In this work, we report in-situ growth of MnCoO nanoneedles and NiFeRu layered double hydroxide (LDH) nanosheets on nickel foam (NF) (MnCoO@NiFeRu-LDH/NF) that can function a highly efficient electrode toward electrocatalysis of OER. Such electrode demands an overpotential of as low as 205 mV to reach 10 mA cm in alkaline electrolyte and can run stably over 120-hours continuous operation. A hybrid flow acid/alkali electrolyzer is set up by using the Pt/C as the acidic cathode coupling with the MnCoO@NiFeRu-LDH/NF as the alkaline anode, which only requires an applied voltage of 0.59 V and 0.94 V to attain an electrolytic current density of 10 mA cm and 100 mA cm, respectively. The present work could push forward the further development of the electricity-saving electrolytic technique for H generation.