Facile Control of C2H5OH Sensing Characteristics by Decorating Discrete Ag Nanoclusters on SnO2 Nanowire Networks

The effect of Ag decoration on the gas sensing characteristics of SnO2 nanowire (NW) networks was investigated. The Ag layers with thicknesses of 5-50 am were uniformly coated on the surface of SnO2 NWs via e-beam evaporation, which were converted into isolated or continuous configurations of Ag islands by heat treatment at 450 degrees C for 2 h. The SnO2 NWS decorated by isolated Ag nano-islands displayed a 3.7-fold enhancement in gas response to 100 ppm C2H5OH at 450 degrees C compared to pristine SnO2 NVVs. In contrast, as the Ag decoration layers became continuous, the response to C2H5OH decreased significantly. The enhancement and deterioration of the C2H5OH sensing characteristics by the introduction of the Ag decoration layer were strongly governed by the morphological configurations of the Ag catalysts on SnO2 NWs and their sensitization mechanism.