Cobalt-iron Co-doped ammonium phosphomolybdate for electrocatalytic oxygen evolution in acidic electrolyte

Abstract

In this study, we investigate the performance of cobalt-iron co-doped phosphomolybdate (CoFe–PMo) as an efficient electrocatalyst for oxygen evolution reaction (OER) in acidic electrolyte. We demonstrate that the introduction of cobalt and iron ions into the phosphomolybdate structure enhances its catalytic activity towards OER. The electrochemical measurements reveal that CoFe–PMo exhibits remarkable stability and improved catalytic activity compared to the undoped amminium phosphomolybdate. The overpotential for OER is only 223 mV at 10 mA cm−2, which is even smaller than that of IrO2.The durable tests maintain its performance over 40 h electrolysis period that the current barely drops. This enhanced performance is attributed to the internal redox between doped cobalt-iron ions and Mo ions in PMo, which promotes the charge transfer and enhances the active sites for OER. The results suggest that CoFe–PMo is a promising catalyst for efficient water splitting in acidic electrolyte, highlighting the potential of cobalt-iron co-doped ammonium phosphomolybdate as a cost-effective and durable electrocatalyst for water splitting for H2 energy in acidic electrolytes.