The Effect of Ar/O 2 and H 2 O Plasma Treatment of SnO 2 Nanoparticles and Nanowires on Carbon Monoxide and Benzene Detection.

As the final piece of a broader study on structure-property performance of SnO2 sensors, this study examines the performance of sensors created from tin(IV) oxide (SnO2 ) nanowires and nanoparticles as a function of temperature for untreated (UT) devices as well as those treated using Ar/O2 and H2 O plasmas. Nanoparticle and nanowire sensors were exposed to air, carbon monoxide (CO), or benzene (C6 H6 ) to determine sensor response (Rair /Rgas ) and sensitivity (Rair /Rgas > 1 or Rgas /Rair > 1). Although both Ar/O2 and H2 O plasma modification minimally increase sensor sensitivity toward CO and C6 H6 under most conditions, this study explores initial plasma parameters of a wide array of plasma precursors to better understand the materials properties and gas-phase species that lead to specific sensing capabilities. In particular, certain Ar/O2 and H2 O plasma treatment conditions resulted in increased sensitivity over UT nanomaterials at 25 and 50 °C, but of greatest importance is the knowledge gained from the combined materials, gas-phase, and sensor performance analysis that provide greater insight for effectively selecting future materials and modification systems to achieve optimal gas sensor performance.