Surfactant assisted solid-state synthesis and gas sensor application of a SWCNT/SnO ₂ nanocomposite material

Although tin oxide has been the most widely investigated metal oxide material for gas detection, it suffers from the large resistance and high operating temperature. This could be overcome by hybridization with nanostructured carbon. In this work, tin oxide nanoparticles with ultrasmall sizes of 1-3 nm have been uniformly coated onto bundles of single-walled carbon nanotubes by a surfactant assisted solid state synthesis approach for the first time. Gas sensor properties of the as-synthesized nanocomposite material toward NO ₂ (from 5 to 60 ppm) are measured at 150 °C. Compared to the pure carbon tubes gas sensors, the nanocomposite gas sensor responds to NO ₂ in low concentrations with good linearity, high sensitivity, and fast recovery, while working at a relatively low temperature.