Nanostructure Bi2WO6: Surfactant-assisted hydrothermal synthesis for high sensitive and selective sensing of H2S

Abstract

Multilayer Bi 2WO6 micro-nano hierarchical structures were prepared via a facile hydrothermal method using sucrose as template in the presence of four kinds of surfactants. The morphologies and phases were determined by SEM, TEM and XRD. All the hierarchical structures Bi 2WO6 are composed of nanocrystals with orthorhombic lattice. The grain size, specific surface areas and pore size vary with the surfactant. And the influence of different surfactants on oxygen vacancy (OV) was investigated by electron paramagnetic resonance (EPR), the sample prepared by F127 has a certain OV concentration and show the highest sensitivity. As gas sensing material, all the hierarchical structures Bi 2WO6 show high selectivity and fast response-recovery characteristic to the H2S at 260 °C. Meanwhile, the sensors presented a favorable linear relationship with the H2S concentration (1∼660 ppm). The sensors based on BWO-F127 exhibit the highest sensitivity to H2S, due to the existed O vacancies, the high specific surface areas and large pore volumes, which can provide potential applications for detecting H2S.