Au-modified α-Fe2O3 nanoparticles for ultrasensitive isopropanol detection

As a typical VOC gas, the harm of isopropanol to human health and the environment cannot be ignored. The detection of isopropanol is of great significance to human safety and environmental protection. Herein, Au/alpha-Fe2O3 sensors with different Au contents were prepared for isopropanol detection using a simple microwave-assisted method. The morphology, structure, and composition of the samples were characterized using SEM, TEM, XRD, and XPS. The gas-sensitive properties of pure alpha-Fe2O3 and Au/alpha-Fe2O3 composites were systematically investigated under different temperatures. It was found that the Au/alpha-Fe2O3 composite (AF) sensors exhibited excellent selectivity and a high response to isopropanol at an optimal operating temperature of 220 degrees C. The gas-sensing performances of the Au-modified alpha-Fe2O3 nanoparticles were significantly improved compared to that of pristine alpha-Fe2O3. Especially, the sample with the Au-modified concentration of 7 mol% exhibited the highest response of 51.47 to 100 ppm isopropanol, which was 4.5 times higher than that of pure alpha-Fe2O3. Moreover, the AF gas sensor displayed great selectivity, reusability, and long-term stability. The enhancement of the gas-sensing performances of the AF composite gas sensors can be attributed to the effects of electronic sensitization and chemical sensitization induced by the introduction of Au nanoparticles, providing a viable solution for detecting isopropanol.

Automated summary

In this study, Au/α-Fe2O3 composite sensors were prepared and exhibited high selectivity and response for isopropanol detection. Especially, the sample with an Au-modified concentration of 7 mol% showed the best performance with a response to 100 ppm isopropanol that was 4.5 times higher than that of pure α-Fe2O3.