Polypyrrole-Tantalum disulfide composite: An efficient material for fabrication of room temperature operable humidity sensor

Polypyrrole-tantalum disulfide (PPy/TaS2) composites were synthesized with varying wt% of TaS2 (10, 30 and 50) by in situ chemical polymerization. XRD spectra of the composites unraveled their crystalline nature. SEM images of the PPy/TaS2-50% composite inferred the uniform distribution of TaS2 in the matrix of PPy with reduced grain size. TaS2 sheets embedded in the PPy matrix and crystalline nature of the composite confirmed from TEM studies. FTIR analysis revealed strong interaction between PPy and TaS2. Humidity sensing performances of the composites were studied in the range of 10-97% RH. Among the composites synthesized, PPy/TaS2-50% composite exhibited good linearity, sensitivity, limit of detection along with a sharp response and recovery times of 10 and 20 s respectively. The sensing mechanism has been discussed on the basis of Grotthuss reaction. (C) 2019 Elsevier B.V. All rights reserved.