Synthesis of dense intersecting branched tree-like ZnO nanostructures and its superior LPG sensing property

Different morphologies of ZnO nanostructures have been synthesized by chemical vapor deposition method by varying the growth temperature from 600 °C to 700 °C. Synthesized samples were characterized by X-ray diffractometry, field emission scanning electron microscopy and photoluminescence measurements. The growth mechanism of the dense intersecting branched tree-like ZnO nanostructures has been explained with the help of a schematic model. The liquefied petroleum gas (LPG) sensing performance by the nanostructures has been examined and it is found that the tree structure shows the highest response to LPG as compared to the other nanostructures with no or small branching. The mechanism of the enhanced gas response property in the tree-like structure has been explained with the help of a surface depletion model.