Researching the crystal phase effect on gas sensing performance in In2O3 nanofibers

Phase structure, specific surface area and composition have great influence on the gas sensing performance, however the dominant factor is still unknown. In this study, In2O3 nanofiber (NF) and In2O3 flower-like nanofibers (FNF) with different phase structures, specific surface areas and morphologies are investigated to obtain in-depth understanding of how different factors alters gas sensing performances. In2O3 NF exhibits the best gas sensing performance towards 100 ppm acetone gas at 180 degrees C with high sensitivity (72), good selectivity and ultra-fast response speed (1 s), while In2O3 FNF shows distinct enhancement of sensing performances toward formaldehyde (14.3 times higher than the sensitivity of In2O3 NF) and obviously decrease in acetone response at 180 degrees C. Such gas sensing behaviors can be attributed to the difference in the oxidation abilities of chemical absorbed oxygen species induced by the variation of phase structure. Our findings not only promote the understanding of sensing reaction process but also pave a new pathway for the design of high-selectivity gas sensors.