Hierarchical CoTe/MnO₂/BN Ternary Composite Exhibiting Energy-Efficient O₂ Evolution in Water

Transition metal tellurides have emerged as leading materials for energy applications due to their unique electrochemical properties. Here, cobalt telluride (CoTe) is tactically included with MnO2 on a boron nitride template via a hydrothermal method to generate the CoTe/MnO2/BN (CTMOBN) ternary heterostructure composite, which was probed for the electrocatalytic oxygen evolution reaction (OER) in water. The CTMOBN material was duly studied via an array of spectroscopic and microscopic techniques, including Fourier-transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. The detailed analysis revealed a hierarchical structure for the composite, with the distinct presence of CoTe nanosheets, MnO2 rods, and boron nitride flakes. The catalytic activity of this ternary CTMOBN composite exhibited efficient OER activity in alkaline aqueous media while displaying a relatively low overpotential of 273 mV to reach an anodic current density of 10 mA/cm2 with a fast catalysis rate (Tafel slope ∼81 mV/dec). The comparative studies also highlighted the significance of the presence of all three components in the composite for displaying such an excellent electrocatalytic OER activity.