Large-scale production of self-assembled SnO2 nanospheres and their application in high-performance chemiluminescence sensors for hydrogen sulfide gas

Abstract

Mesoporous SnO₂ nanospheres with high thermal stability have been fabricated via reaction of sodium stannate with CO₂ controllably released from urea under hydrothermal conditions. The resultant products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen sorption and FTIR analysis. It was indicated that the products exhibited nearly monodisperse mesoporous or hollow spherical nanostructures with sizes in the range of ca. 25–50 nm, which were composed of nanocrystals with sizes of less than 10 nm. The formation mechnism of SnO₂ nanospheres was also discussed. Urea not only acted as the CO₂ resource for the formation of SnO₂ primary nanocrystals, but also played an important role in their self-assembly into nanospheres. The as-prepared SnO₂ nanospheres exhibited superior sensitivity, high selectivity, and extremely rapid response for detecting H₂S gas based on catalytic chemiluminescence (CL) characteristics.