Improved acetone sensing characteristics of TiO2 nanobelts with Ag modification

Abstract Gas sensors based on TiO2 have been intensively studied owing to their good sensing capability and stability under extreme conditions as well. However, the limited operating temperature and low selectivity are the major concerned issues. The present work is aimed at the facile synthesis of TiO2 nanobelts (NBs) modified with silver (Ag) showing improved sensitivity to acetone gas. It was found that the 3% Ag-modified TiO2 NBs samples present the excellent acetone sensing properties in terms of high response (SR~ 28.25 towards 500 ppm), short response (~ 6 s) and recovery (~ 8 s) time, good linear dependence (R2~ 0.9940) with the acetone concentration, superior long-term stability within 1 month and high selectivity against other gases (SF~ 13.3), suggesting the potential of Ag-modified TiO2 NBs for acetone gas sensor application. Moreover, a probable sensing mechanism for the improved response of Ag-modified TiO2 NBs towards acetone is also discussed based on the crystal structure, morphology and elemental composition.