Engineering Cu–O–Fe interfaces in CuFe2O4/α-FeOOH catalysts for enhanced electrochemical H2O2 sensing

Hydrogen peroxide (H 2 O 2 ) detection is of great significance in environmental monitoring, food safety, and clinical diagnosis. Copper doping into α-FeOOH nanorods significantly enhanced the sensitivity and stability for electrochemical detection of H 2 O 2 . The structure and surface morphology of the products were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The electrochemical properties of CuFe 2 O 4 /α-FeOOH were studied by cyclic voltammetry and amperometry. The results showed that the composition and morphology of the as-prepared products were dependent on the Cu doping level. When the Cu doping level was up to 10 mol%, a spinel copper ferrite (CuFe 2 O 4 ) phase was formed in the product, accompanied by a morphological evolution into nanoparticles. The CuFe 2 O 4 /α-FeOOH/FTO (Fluorine-doped tin oxide) electrode exhibited excellent performance to detection of H 2 O 2 with high sensitivity (125.86 μA·mM −1 ·cm −2 ) and a low detection limit (0.56 μM, S/N = 3). Finally, the possible mechanism of the CuFe 2 O 4 /α-FeOOH catalysts for H 2 O 2 detection was analyzed and discussed.