Networked Mixed Metal Oxide (V+4 and Ti+4) Nanostructures as Potential Material for Trimethylamine Detection
Highly sensitive and selective recognition of trimethylamine (TMA) in environment plays an important role in preserving human health and better air quality. There have been huge number of attempts on mono oxides of VO2 and TiO2 thin films that would detect several volatile vapours and gases, but, they lack in reaching the sensitivity and stability for the real-time use. Though VO2 - TiO2 (VTO) mixed oxides have been broadly used for its effective catalytic reduction properties till date, it’s material property in chemical sensing have not been investigated yet. Also, as demand for simple, low cost and highly sensitive TMA sensors are high, mixed oxide will be an attractive alternative. Hence, for the first time we devote attention on exploring the possibility of using VTO mixed oxide thin film by realizing the combination of its pure better sensing capabilities for TMA sensing. Herein, VTO thin films were deposited using reactive co-sputtering technique and demonstrated the TMA sensing performance at room temperature (~30°C) in the range of 5 to 300 ppm. It was found that, VTO mixed oxide thin film delivered novel features with excellent TMA sensing properties and improved selectivity than bare VO2 and TiO2 thin films. We demonstrated its versatility to detect TMA (CH3)3N)) in comparison to other environments such as ammonia (NH3), acetone (C3H6O), dimethylamine ((CH3)2NH)), ethanol (C2H5OH), formaldehyde (HCHO), isopropyl alcohol (C3H8O) and methanol (CH3OH) to prove its high sensitivity towards TMA. The effect of percolation regime, sensing mechanism with band bending of the deposited thin films towards TMA vapours have been discussed.