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 single-step process has been demonstrated as the sensor material for selective detection of methanol vapor. Different techniques like Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, X-ray diffraction spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to evaluate the interfacial interactions between PmAP and Cu nanoparticles within their conducting nanocomposites. The induced doping interaction through fluctuating electrostatic charge transfer between free –OH groups of the PmAP and Cu nanoparticles was confirmed from the spectral characterizations. About 3 wt% of Cu nanoparticles having average size of around 30–50 nm confirmed by the SEM and TEM analysis, 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 reproducibility of the nanocomposites were studied towards methanol vapor at different concentrations. The mechanism of selective methanol vapor sensing by PmAP/Cu nanocomposite film has been explained on the basis of selective dipole interaction characterized by zeta potential measurement. Graphical Abstract