Biologically templated Fe2O3–CuO heterojunction for ppb-level styrene gas detection

Abstract

The widespread industrial use of styrene highlights the urgent need for detecting and monitoring its harmful gases. The innovation of this study lies in synthesizing uniform Fe2O3 nanoparticles using Ginkgo biloba and calcining them with CuOHF to prepare nanostructured materials, enhancing the performance of gas sensors. The effects of varying α-Fe2O3 additions and calcination temperatures on the structure and gas-sensitive properties of the composites were systematically investigated. The results revealed that the optimal operating temperatures of the CuO–10%Fe2O3-400 sensor were reduced by 80 and 50 °C, and its response to 100 ppm styrene at 200 °C was significantly enhanced by 3.2-fold and 4.2-fold, respectively, compared to the single Fe2O3 and CuOHF sensors. It is particularly noteworthy that the sensor exhibits excellent detection performance at a 50 ppb styrene concentration, with a response value of 1.2. The lamellar structure of CuOHF serves as a precursor for CuO, thereby increasing the surface area of the sensor in contact with the gas. During the calcination process, the released gases contribute to the formation of a porous structure, which together improves the adsorption capacity and stability of the sensor. Additionally, the heterojunction formed by the calcination of CuO (p-type) and Fe2O3 (n-type) enhances charge transfer and increases gas adsorption capacity, highlighting its potential as a gas sensor. This composite material exhibits good sensitivity and reliability in monitoring hazardous gases like styrene, underscoring the significant value of this study in environmental monitoring and safety control.