Synthesis of porous CuO microspheres assembled from (001) facet-exposed nanocrystals with excellent glucose-sensing performance

Abstract

Hierarchical porous CuO microspheres are successfully synthesized through a facile hydrothermal method using Na2HPO4-NaOH buffer solution as solvent. The SEM and TEM results reveal that the CuO microspheres are assembled by (001) facet-exposed nanocrystals. The BET result indicates that the CuO microspheres have a surface area of 61.9 m2 g−1 and an average pore size of ∼3.7 nm. Moreover, it is found that the buffer solution not only serves as reactant and medium, but also affects the final shape of the CuO microspheres. The buffer solution can supply a suitable amount of OH− ions, which leads to no extra OH− ions absorb on the original crystals, thus favoring to form into 3D spherical microstructure. In addition, the CuO microspheres are used as the electrodic material for non-enzymatic glucose sensor, which present low detection limit (0.50 μM), fast amperometric response time (3 s), and wide linear range (0.001–4.0 mM). The improved electrocatalytic performance is ascribed to the synergistic effect of exposure of (001) facet, large special surface area, and porous structure.