Gas sensing properties of hydrothermally grown ZnO nanorods with different aspect ratios

ZnO nanorods (ZNRs) with different aspect ratios were grown on seeded glass substrates by hydrothermal method. The influence of concentration of zinc precursor (zinc nitrate) in the solution on the formation of ZNRs was studied. Photoluminescence (PL) studies revealed the enhanced defect related emission with increasing aspect ratio of ZNRs. LPG (liquefied petroleum gas) sensing properties of ZNRs with different aspect ratios were studied. The ZNRs with high aspect ratio have shown significantly better LPG sensing performance than ZNRs with low aspect ratio. The LPG response of ZNRs was studied by varying gas concentration from 250 to 2000 ppm at operating temperature 350 °C. The relationship between PL and LPG sensing properties of ZNRs is established. Our results demonstrate that hydrothermally grown vertically aligned ZNRs arrays are promising for the fabrication of cost effective and high performance LPG sensor.