Impact of interfacial interactions on optical and ammonia sensing in zinc oxide/polyaniline structures

Zinc oxide/polyaniline (ZnO/PANI) hybrid structures have been investigated for their optical and gas sensing properties. ZnO nanoparticles, prepared by the sol–gel method, pressed in the form of pellets were used for gas sensing. The hybrid ZnO/PANI structure was obtained by the addition of PANI on the surface of ZnO. The UV–Vis absorption of the modified pellets show band edge at 363 nm corresponding to ZnO, while a change in the absorption peaks for PANI was observed. The possible interaction between Zn2 + of ZnO and NH-group of PANI was confirmed using Raman spectroscopy studies. The results reveal that the hybrid structures exhibit much higher sensitivity to NH\(_{{3}}\) gas at room temperature than blank ZnO, which is sensitive to NH3 gas at higher temperature. This enhancement has been attributed to the creation of active sites on the ZnO surface due to the presence of PANI.