Facile synthesis of nano-structured SnO2 films and their properties in ethanol gas sensing

Abstract

Four types of nano-structured SnO2 thin films were synthesised via a facile one-step hydrothermal method on Ti substrate. All the films were prepared by using SnCl4 and NaOH as the precursors with urea, mercaptoacetic acid or sodium citrate as the adjusting reagent. The prepared films were characterised by scanning electron microscope, X-ray diffractometer, X-ray photoelectron spectroscopy (XPS) and their properties in ethanol gas sensing were examined. It was found that addition of organic reagents resulted in the formation of different nano-scaled morphologies, i.e. nanowires, nanonets, transparent nanosheets and nanograsses. The characterisation of XPS indicated that SnO2 was successfully deposited. The gas sensing experiments revealed that morphologies of the nano-SnO2 films had a great effect on their gas sensing properties. The possible reasons involved were presented.