Selective Sensing of Methanol by Poly(m-aminophenol)/Copper Nanocomposite

The nanocomposite film of conducting poly(m-aminophenol) with copper nanoparticles (PmAP/Cu) prepared by a singlestepprocess has been demonstrated as the sensor material for selective detection of methanol vapor. Different techniques likeFourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, X-ray diffraction spectroscopy, scanning electronmicroscopy (SEM) and transmission electron microscopy (TEM) were used to evaluate the interfacial interactions betweenPmAP and Cu nanoparticles within their conducting nanocomposites. The induced doping interaction through fluctuatingelectrostatic charge transfer between free –OH groups of the PmAP and Cu nanoparticles was confirmed from the spectralcharacterizations. About 3 wt% of Cu nanoparticles having average size of around 30–50 nm confirmed by the SEM and TEManalysis, was optimized inside the PmAP matrix in terms of better dispersion as well as achieving the highest conductivity(1.05 × 10−6 S/cm). The sensing performances, viz., % response, response time, recovery time, selectivity and reproducibilityof the nanocomposites were studied towards methanol vapor at different concentrations. The mechanism of selectivemethanol vapor sensing by PmAP/Cu nanocomposite film has been explained on the basis of selective dipole interactioncharacterized by zeta potential measurement.