UV-enhanced room temperature gas sensor based on hollow sphere SnO2-TiO2

Sensing characteristics of the UV-enhanced gas sensor using the SnO
₂
-TiO
₂
hollow sphere (HS SnO
₂
-TiO
₂
) at room temperature has been investigated. HS SnO
₂
-TiO
₂
was prepared by coating the TiO
₂
on the outer- and inner-surfaces of HS SnO
₂
with hydrolysisof the titanium tetrachloride. HS SnO
₂
was synthesized by chemically induced self-assembly under hydrothermal condition. The morphology, crystalline structure and optical absorptivity of the HS SnO
₂
-TiO
₂
were measured by means of X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and UV-Vis absorption spectra. A sensing mechanism related to the SnO
₂
-TiO
₂
heterojunction as well as UV illumination was proposed.