Novel methyl‐orange assisted core‐shell polyaniline‐silver nanosheets for highly sensitive ammonia chemiresistors
Vishal Chaudhary, Murthy Chavali
Abstract
Abstract A cost‐effective, eco‐friendly, one‐pot synthesis of a new class of homogenous core‐shell polyaniline‐silver nanocomposite was fabricated with the assistance of supramolecular aggregates of amphiphilic methyl‐orange (MO) and oxidant ions of silver nitrate (AgNO 3 ). The morphology of nanocomposite transforms from spherical (core‐shell type: PA‐1) to plate‐like polygonal particles (PA‐2) with surge in concentration of AgNO 3. The strong contrast of the TEM images depicts the presence of silver (Ag) at core and polyaniline (PAN) at the shell. The core‐shell structure of the synthesized nanocomposite was confirmed using KCN washing technique. The SAED pattern reveals the hexagonal nature of PAN‐Ag hybrid nanosheets with [111] orientation with interplanar spacing around 2.4 Å corresponding to face‐centered‐cubic structure of Ag. The X‐ray diffraction spectra reveal the crystalline nature of the hybrid. Furthermore, the chemiresistors fabricated using the PA nanocomposite was analyzed for ammonia (NH 3 ) monitoring behavior. The fabricated room temperature chemiresistor was found to be highly sensitive (~47.1% sensitivity) towards low concentration (as low as 1 ppm) of NH 3 with high selectivity and stability, which opens a new window for fabricating cost‐effective commercial sensors.