Electrochemical Detection of H₂O₂ Using Bi₂O₃/Bi₂O₂Se Nanocomposites

The development of high-performance hydrogen peroxide (H₂O₂) sensors is critical for various applications, including environmental monitoring, industrial processes, and biomedical diagnostics. This study explores the development of efficient and selective H₂O₂ sensors based on bismuth oxide/bismuth oxyselenide (Bi₂O₃/Bi₂O₂Se) nanocomposites. The Bi₂O₃/Bi₂O₂Se nanocomposites were synthesized using a simple solution-processing method at room temperature, resulting in a unique heterostructure with remarkable electrochemical characteristics for H₂O₂ detection. Characterization techniques, including powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM), confirmed the successful formation of the nanocomposites and their structural integrity. The synthesis time was varied to obtain the composites with different Se contents. The end goal was to obtain phase pure Bi₂O₂Se. Electrochemical measurements revealed that the Bi₂O₃/Bi₂O₂Se composite formed under optimal synthesis conditions displayed high sensitivity (75.7 µA µM^-1 cm^-2) and excellent selectivity towards H₂O₂ detection, along with a wide linear detection range (0-15 µM). The superior performance is attributed to the synergistic effect between Bi₂O₃ and Bi₂O₂Se, enhancing electron transfer and creating more active sites for H₂O₂ oxidation. These findings suggest that Bi₂O₃/Bi₂O₂Se nanocomposites hold great potential as advanced H₂O₂ sensors for practical applications.