Evaluation of Heat Treatment Effects on the Electrocatalytic Properties of AuCu Intermetallic Nanocrystals

Abstract

In this report, Au@CuO core-shell nanocrystals (NCs) were prepared by direct heat-treatment of AuCu intermetallic nanocrystals (iNCs), which were synthesized by an one-pot wet chemical method in the synergistic system of oleylamine and oleic acid. After heat-treatment, the structure of AuCu iNCs changed from intermetallic into Au@CuO core-shell structure, which exhibited significantly improved catalytic activity toward the oxidation of glucose than AuCu iNCs. The effects of heat-treatment on the structure of AuCu iNCs were discussed based on various instruments characterizations, and the possible formation mechanism of Au@CuO core-shell nanocrystals was also proposed in this work. The electrocatalytic activity toward glucose was evaluated by cyclic voltammetry (CV) and amperometry. It was found that the indium tin oxide (ITO) electrode modified by prepared Au@CuO NCs (Au@CuO NCs-ITO) had much higher electron transfer rate and electrocatalytic activity toward glucose oxidation than that of the AuCu iNCs-ITO electrode in alkaline solution. And it has attractive features of good selectivity, stability and reproducibility for glucose detection. These results indicate that Au@CuO NCs-ITO electrode is a promising candidate for amperometric non-enzymatic glucose detection.