Phase Selective Synthesis of Unique Cobalt Telluride Nanofleeces for Highly Efficient Oxygen Evolution Catalyst

Co-based nanomaterials have been intensively explored as promising noble metal free oxygen evolution reaction (OER) electrocatalysts. Herein, we first report phase selective synthesis of novel hierarchical CoTe2 and CoTe nanofleeces for efficient OER catalyst. The CoTe2 nanofleeces exhibited excellent electrocatalytic activity and stablity for OER in alkaline media. It has been discovered that the CoTe2 catalyst exhibited superior OER activity to the CoTe catalyst and comparable to the state-of-the-art RuO2 catalyst. Density functional theory calculations showed that the binding strength and lateral interaction of the reaction intermediates on CoTe2 and CoTe are essential for the order of their overpotential and the trend variation at different condition. This study provides value insights for rational design of noble metal free OER catalysts with high performance and low cost by use of Co-based chalcogenides.