Facile synthesis of nano‐structured SnO ₂ films and their properties in ethanol gas sensing

Abstract

Four types of nano-structured SnO 2 thin films were synthesised via a facile one-step hydrothermal method on Ti substrate. All the films were prepared by using SnCl 4 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 SnO 2 was successfully deposited. The gas sensing experiments revealed that morphologies of the nano-SnO 2 films had a great effect on their gas sensing properties. The possible reasons involved were presented.