Boosting Glucose Oxidation by Constructing Cu-Cu2O Heterostructures

Cuprous oxide (Cu2O) is an important p-type semiconductor and widely used in electrocatalytic filed. However, the limited number of active sites and its poor conductivity make it difficult to further improve its catalytic activity. Here, we adopt a two-step method through reduction of Cu2+ at alkaline condition at a low temperature and further processed a heat treatment to fabricate Cu-Cu2O heterostructures in the presence of PVP. When used as catalyst for glucose oxidation, Cu-Cu2O heterostructures not only preserve abundant active sites to react with glucose molecules, the metallic Cu simultaneously provides a highly conductive path for electrical charges transfer during the electrocatalytic oxidation reaction of glucose. As a result, the Cu-Cu2O heterostructure exhibits enhanced electrocatalytic activity toward glucose oxidation in 0.1 M NaOH solution compared to Cu2O individual, and the fabricated non-enzymatic glucose sensor offers a low detection limit of 1.4 μM (S/N=3), a high sensitivity (1446 A mM−1 cm−2), and a wide linear range (0.002 - 4 mM) at a working voltage of 0.55 V (vs. SCE) in alkaline solution. The as-prepared Cu-Cu2O heterostructure has a high catalytic activity, providing a new strategy for the design of other electrocatalysts.