Atomically dispersed cobalt-based species anchored on polythiophene as an efficient electrocatalyst for oxygen evolution reaction

Highlights: • We prepared a novel atomically dispersed OER electrocatalyst Co@PTh. • A novel cobalt-based catalytic site structure, Co_xO_yS₄, is successfully fabricated. • Analysis of XANES and EXAFS results confirm the presence of atomically dispersed CoxOyS₄. • Atomically dispersed cobalt are anchored on polythiophene (PTh) through CoS bond. • Co@PTh shows excellent OER activity, superior to RuO₂, and comparable with IrO₂. For clean and renewable energy conversion systems, it is important to develop efficient, earth-abundant, low-cost and stable electrocatalysts for oxygen evolution reaction (OER). Herein, we prepared an atomically dispersed cobalt coordinated with oxygen and sulfur species on the conductive polymer polythiophene (PTh) via CoS bond as a stable noble-metal-free electrocatalyst for the OER. A novel cobalt-based catalytic site structure, Co_xO_yS₄, is successfully fabricated. The resulting electrocatalyst, Co@PTh, exhibits an excellent OER performance with overpotential of 338 mV versus reversible hydrogen electrode (RHE) at a current density of 10 mA cm⁻² and the Tafel slope of 52 mV dec⁻¹ in alkaline electrolyte. This performance is better than that of the commercial RuO₂ and even comparable with the state-of-the-art catalyst IrO₂. Our work suggests that the atomically dispersed cobalt-based species decorated PTh may be a good alternative for precious-metal-based catalysts.