Polyaniline/Graphene oxide composite as an Ultra-Sensitive humidity sensor

This paper investigated the humidity-sensing response of polyaniline/Graphene oxide (PGO) composites. Graphene oxide (GO) was synthesised using the improvised hummers method, and polyaniline (PANI) was synthesised using the chemical in-situ polymerisation process. By adding different weights per cent (wt%) of Graphene oxide (GO) to the polymer matrix, PGO composites were prepared. Structural and morphological properties of GO were confirmed by XRD, RAMAN, FTIR, SEM, EDX, and HR-TEM (elementary mapping) characterisations. The XRD, FTIR SEM and EDX proficiencies were employed to characterise the PGO composites. To experience the humidity response performance, the film of PANI, GO, and PGO samples was groomed by wedging the sample on an IDT substrate using a drop casting technique. Among the samples, the PGO-3 composite (polyaniline/Graphene oxide 15 wt%) depicted a maximum sensing response (SH) of 93.4 % with a dynamic timing behaviour of 4 s and 7 s. The Nobel characters, such as low accurate Sensing response, fewer detection limits (LOD), negligible hysteresis and perfect stability, were observed in the PGO-3 composite. The physical properties such as porosity, water content, and degree of swelling have been outstandingly enhanced in the PGO-3 composite compared to PANI and GO. The mechanism for sensing the PGO-3 composites was deliberately explained based on establishing superficial physisorption, chemisorption layers, and later capillary condensation.