In situ electrodeposition of mesoporous aligned α-Fe2O3 nanoflakes for highly sensitive nonenzymatic H2O2 sensor

Mesoporous aligned hematite nanoflakes (MA-α-Fe₂O₃) were in situ electrochemically synthesized on the fluorine-doped tin oxide coated glass (FTO) substrate and studied for electrocatalytic reduction and sensing H₂O₂. Morphology and crystallinity of films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM). The vertical aligned MA-α-Fe₂O₃ mesostructured films showed (1 1 0) preferential growth, offering both the fast electron transfer path and diffusion of reactants and products. Thus the sensing performance of MA-α-Fe₂O₃ displayed an unprecedented sensitivity of 422.5 μA/(mM cm²), a wide linear range up to 3.145 mM and an excellent detection limit of 22 μM. Furthermore, the sensor also exhibited good anti-interference, reproducibility, stability, feasibility for real sample detection. These results indicated that MA-α-Fe₂O₃ could be a promising electrochemical material as nonenzymatic H₂O₂ sensor.