Potentiallity of Surface Modified TiO2 Nanoflowers for Alcohol Sensing Application

Abstract

The current paper aims about the study of alcohol sensing performance in surface modified TiO2 nanoflowers based binary hybrid devices, incorporating Pd and rGO as a secondary material for surface modification, separately. Two types of binary hybrid composite were studied. In one, the surface of pristine TiO2 nanoflowers was modified by noble metal catalyst Pd (Pd-TNFs). Whereas, for the other case, the surface of the pristine structure was decorated by 2D material rGO (rGO-TNFs). To authenticate, the structural and morphological properties of the hybrid structure, the following characterizations viz. FESEM, XRD and Raman spectroscopy were performed. Methanol and ethanol were used here as the test VOCs in the concentration range of 10-700 ppm for the hybrid sensor devices. The sensing performance was studied in the temperature range of $27^{\circ}\mathrm{C}-180^{\circ}\mathrm{C}$ and the corresponding transient characteristics of the hybrid devices were given at optimum temperature only. It was revealed from the above study that in between ethanol and methanol, the sensing performance in terms of response magnitude was promising towards ethanol compared to methanol, for these hybrid devices. Moreover, the methanol sensing performance was significantly improved in these hybrid structures compared to its pristine TiO2 nanoflowers counterpart due to the surface modification techniques.