Synthesis of vanadia nanorod arrays and their novel applications as alco-sensors

Vanadia (V2O5) nanorod arrays were grown by oxidizing vanadium foil at five different voltages for 3 h through electrochemical anodic oxidation method. Dense aligned nanorods with L/D ratio 4.75-4.88 (diameter D ≈ 40-45 nm and length ≈ 190-220 nm) were grown at the optimized voltage 55 V. The dominant existence of V2O5 phase and its layered structure were verified by XPS and Raman spectrum analysis respectively. Linear I-V characteristic curve of the sensor based on V2O5 nanorod arrays confirms its Ohmic contact with the electrodes. Gas sensing investigations of the sensor reveals its n-type behavior with the average response magnitude of 6.13 in N2 atmosphere, which signifies the industrial application of the sensor in a gaseous atmosphere. The sensor shows remarkable static response towards ethanol with lower detection threshold of 800 ppb and a maximum response magnitude of 7.27 at 500 ppm. Based on variable resistance model, a suitable gas sensing mechanism is also established.