Enhanced gas sensing property of SnO2 nanoparticles by constructing the SnO2-TiO2 nanobelt heterostructure

Heterostructures constituted of SnO2 nanoparticles deposited on TiO2 nanobelt (SnO2 NP/TiO2 NB) or on surface-coarsened TiO2 nanobelts (SnO2 NP/TiO2 SNB) were successfully synthesized through a simple hydrothermal process. Using acetone as analyte, the performance of these two heterostructures as gas sensor were compared to a conventional SnO2 NP gas sensor. The SnO2 NP/TiO2 SNB heterostructure exhibited the best gas sensing performance in terms of sensitivity and response/recovery time. The high sensitivity of the SnO2/TiO2 SNB sensor originates from the large surface area offered by SnO2 NPs. The short response/recovery time is attributed to the high carrier transport speed along the long axis of the 1-dimensional TiO2 NB. We have thus demonstrated that the construction of a heterostructure leads to an improvement in the performance of a gas sensor, and we believe this strategy could be applied to many sensor devices. (C) 2015 Published by Elsevier B.V.