3D ordered macroporous SmCoO3 perovskite for highly active and selective hydrogen peroxide detection

Abstract

We reported the direct electrochemical hydrogen peroxide detection on three-dimensionally ordered macroporous SmCoO3 (3DOM-SmCoO3) perovskite oxide electrode synthesized via a poly (methyl methacrylate) (PMMA) colloidal crystal templating route. The low-cost and simple 3DOM-SmCoO3 sensor not only overcome the various disadvantages of enzyme- and noble metal-based sensors but also display a superior sensing performance for H2O2 detection. More importantly, using 800 nm PMMA microspheres, a hexagonally ordered macroporous crystalline structure can be created, which features large surface area (20.14 m2 g−1) and large, open, interconnected channels for facile reactants and ions diffusions. The resultant 3DOM-SmCoO3 synthesized using 800 nm PMMA microspheres template (3D-SC-800) displayed higher sensitivity (715 and 460 μA mM−1 cm−2), lower limit of detection (0.004 μM), larger detection linear range (0.1–10,000 μM), and higher selectivity in the presence of interfering species (i.e., glucose, ascorbic acid, dopamine, and uric acid), for H2O2 detection, relative to SmCoO3 (SC) and SmCoO3 synthesized using 200 nm PMMA template (3D-SC-200). Our comprehensive electrochemical characterization attributes the superior H2O2 electrooxidation performance of 3D-SC-800 to its fast electron transfer kinetics and diffusion rate. What we demonstrated here bolsters the future opportunity to harness ordered macroporous perovskite oxide-based materials for highly active and selective non-enzymatic H2O2 detection.