Size controlled V2O5-WO3 nano-islands coated polypyrrole matrix: A unique nanocomposite for effective room temperature ammonia detection

Abstract

Unique metal oxide nanomaterials represent prominent interest owing to their low cost, ease of fabrication and vast number of detectable gases in resistive based gas sensors. Unfortunately they are limited by their dependence of operating temperature, power consumption, poor sensitivity and deterioration of sensing material after continuous usage. To get the better of, conducting polymer polypyrrole has been widely used for fulfilling the requirement as ideal sensing material in sensing field due to its chemical stability, high electron affinity, controllable electrical conductivity and excellent room temperature operation. In this article, we report room temperature responsive ammonia gas sensing material PPy with V2O5 and WO3 developed by in situ chemical oxidation polymerization method. Characterizations carried out using the UV–vis, FTIR, XRD, XPS, SEM, HR-TEM, AFM analysis techniques. Physical and chemical analysis results reveal that the nanocomposite was synthesized successfully without other impurities. The morphological analysis exhibits that V2O5 and WO3 nanoparticles were wrapped and connected over PPy surface as nano islands provides enhanced sensing properties towards selectively NH3with ultrahigh sensitivity of 85 % with response time of 73 s and recovery time 101 s. The outstrip performance of gas sensing esteems were corresponds to the valid p-n heterojunctions of V2O5-WO3 and excellent surface effect of PPy.