Self‐Supporting AuCu@Cu Elongated Pentagonal Bipyramids Toward Neutral Glucose Sensing

Abstract

Controlling the electronic structure of a catalyst has become an important approach to tune and optimize its antipoisoning ability and catalytic efficiency for a chemical reaction. Using d‐mannitol as a structure‐directing agent to induce size transformation and twinned defects in copper particles, penta‐twinned Cu elongated pentagonal bipyramids as supports have been synthesized, and HAuCl4 is reduced in situ to form an AuCu alloy on the surface of Cu, generating a self‐supporting AuCu@Cu core–shell structure for application as a glucose sensor in a neutral medium. The AuCu@Cu elongated pentagonal bipyramids with 0.42 at% Au show activities comparable with the Au and Pt catalyst but are more tolerant toward Cl− than Au and more tolerant toward H3–xPO4x− than Cu. The mass activity of AuCu@Cu reaches 0.10 A mg−1 of Au at 0.6 V versus Ag/AgCl (3 m KCl) in a pH 8.0 buffer. The self‐supporting AuCu@Cu elongated pentagonal bipyramids are promising catalysts for glucose sensing in a neutral medium. This work offers an effective way to design antitoxic and durable catalysts with ultralow content of noble metal for glucose sensing.