Phase-Selective Syntheses of Cobalt Telluride Nanofleeces for Efficient Oxygen Evolution Catalysts

Cobalt-based nanomaterials have been intensively explored as promising noble-metal-free oxygen evolution reaction (OER) electrocatalysts. Herein, we report phase-selective syntheses of novel hierarchical CoTe₂ and CoTe nanofleeces for efficient OER catalysts. The CoTe₂ nanofleeces exhibited excellent electrocatalytic activity and stablity for OER in alkaline media. The CoTe₂ catalyst exhibited superior OER activity compared to the CoTe catalyst, which is 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 determining the overpotential required under different conditions. This study provides valuable insights for the rational design of noble-metal-free OER catalysts with high performance and low cost by use of Co-based chalcogenides.