Exploring Bi₂Te₃ nanoplates as versatile catalysts for electrochemical reduction of small molecules

Abstract

The electroreduction of small molecules to high value-added chemicals is considered as a promising way toward the capture and utilization of atmospheric small molecules. Discovering cheap and efficient electrocatalysts with simultaneously high activity, selectivity, durability, and even universality is desirable yet challenging. Herein, it is demonstrated that Bi₂Te₃ nanoplates (NPs), cheap and noble-metal-free electrocatalysts, can be adopted as highly universal and robust electrocatalysts, which can efficiently reduce small molecules (O₂, CO₂, and N₂) into targeted products simultaneously. They can achieve excellent activity, selectivity and durability for the oxygen reduction reaction with almost 100% H₂O₂ selectivity, the CO₂ reduction reaction with up to 90% Faradaic efficiency (FE) of HCOOH, and the nitrogen reduction reaction with 7.9% FE of NH3. After electrochemical activation, an obvious Te dissolution happens on the Bi₂Te₃ NPs, creating lots of Te vacancies in the activated Bi₂Te₃ NPs. Theoretical calculations reveal that the Te vacancies can modulate the electronic structures of Bi and Te. Such a highly electroactive surface with a strong preference in supplying electrons for the universal reduction reactions improves the electrocatalytic performance of Bi₂Te₃. The work demonstrates a new class of cheap and versatile catalysts for the electrochemical reduction of small molecules with potential practical applications.