Synthesis and trimethylamine sensing properties of spherical V2O5 hierarchical structures

Spherical V2O5 hierarchical structures made up of nanosheets have been synthesized via a facile hydrothermal method without any surfactants and a following annealing process in air. The structure, chemical compositions and morphological features of the V2O5 sample have been investigated through XRD, XPS, SEM and TEM. Besides, the optical properties and the growth period are also investigated. Sensors based on spherical V2O5 hierarchical structures exhibit good selectivity to trimethylamine (TMA), fast response/recovery times (5/28 s), and good stability and repeatability at an operation temperature of 240 degrees C with a gas concentration of 100 ppm. All these properties are related to the unique 3D spherical hierarchical structures. Finally, a gas sensing mechanism based on the chemisorption process is proposed.