Improved acetone sensing characteristics of TiO2 nanobelts with Ag modification

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 (S-R similar to 28.25 towards 500 ppm), short response (similar to 6 s) and recovery (similar to 8 s) time, good linear dependence (R-2 similar to 0.9940) with the acetone concentration, superior long-term stability within 1 month and high selectivity against other gases (S-F similar to 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. (C) 2021 Elsevier B.V. All rights reserved.