Ultralow‐Overpotential Acidic Oxygen Evolution Reaction Over Bismuth Telluride–Carbon Nanotube Heterostructure with Organic Framework

Abstract

The state-of-the-art iridium and ruthenium oxides-based materials are best known for high efficiency and stability in acidic oxygen evolution reaction (OER). However, the development of economically feasible catalysts for water-splitting technologies is challenging by the requirements of low overpotential, high stability, and resistance of catalysts to dissolution during the acidic oxygen evolution reaction . Herein, an organometallic core-shell heterostructure composed of a carbon nanotube core (CNT) and bismuth telluride (Bi₂Te₃) shell (denoted as nC-Bi₂Te₃) is designed and use it as a catalyst for the acidic OER. The proposed catalyst achieves an ultralow overpotential of 160 mV at 10 mA cm^-2 (geometrical), thereby outperforming most of the state-of-the-art precious-metal-based catalysts. The low Tafel slope of 30 mV dec^-1 and charge transfer resistance (R_CT) of 1.5 Ω demonstrate its excellent electrocatalytic activity. The morphological and chemical compositions of nC-Bi₂Te₃ enable the generation of ─OH functional group in the Bi─Te sections formed via a ligand support, which enhances the absorption capacity of H⁺ ions and increases the intrinsic catalytic activity. The presented insights regarding the material composition-structure relationship can help expand the application scope of high-performance catalysts.