Growth of Cu particles on a Cu2O truncated octahedron: tuning of the Cu content for efficient glucose sensing

Abstract

A simple and versatile hydrothermal method is developed to synthesize Cu–Cu₂O, in which Cu particles grow on the surface of a Cu₂O truncated octahedron. Through the reduction of Cu²⁺ by glucose in an alkaline solution, the Cu₂O truncated octahedron is quickly formed via a kinetic control process, and then Cu particles selectively nucleate on the high-energy (110) facets of Cu₂O, generating a heterostructure. The amount of Cu in the sample is successfully tuned by varying the reaction temperature. Compared to Cu₂O, the hybrid Cu–Cu₂O architecture shows superior electrocatalytic performance for glucose oxidation due to the synergistic effect between more electrocatalytic active but less conductive Cu₂O and more conductive but less electrocatalytic active Cu. By tuning the content of Cu in the heterostructure, the highest electrocatalytic activity is achieved at the Cu/Cu₂O molar ratio of 0.83.