Double-shelled hollow sphere V2O5-based conductometric ethanol gas sensor

Hollow nanoarchitectures-based metal oxide semiconductor (MOS) materials have exhibited signal enhancement in gas sensors. However, the mechanism behind the sensing process and how to further improve the sensing performance is still challenging. In this study, three types of V 2 O 5 nanostructures including single-shelled hollow V 2 O 5 (S-V 2 O 5 ), double-shelled hollow V 2 O 5 (D-V 2 O 5 ), and V 2 O 5 nanosheets (ST-V 2 O 5 ) were fabricated and taken ethanol sensing as an example to study the structure-dependent sensing mechanism systematically. The response of D-V 2 O 5 (80%) to 100 ppm ethanol at 240°C was twice that of S-V 2 O 5 (36%) and ST-V 2 O 5 (34%). This is due to the rich pore structure and enlarged specific surface area of D-V 2 O 5 effectively improving the utilization of active sites and the adsorption-desorption process of target gases on the sensor surface. The present work provides a simple approach to boost the sensitivity of MOS gas sensors and proves the way for the realization of high-performance sensor fabrication.