Ternary nanocomposite comprising MnO₂, GQDs, and PANI as a potential structure for humidity sensing applications

Humidity sensing has been offering a noticeable contribution in different industrial, medical, and agricultural activities. Here, graphene quantum dots doped with polyaniline (PANI) and MnO₂ were successfully prepared. The synthesized system is exposed to a set of structural, morphological, and optical investigations. The apparent crystallite size is less than 30 nm, reflecting the nanoscale of the structure, and thus validating the preparation route as evident on XRD pattern. SEM images show a fibrous structure where polyaniline dominates and covers most of the structure's surface. The evident bands of the FTIR spectrum are designated to the component used in synthesis confirming the chemical structure of the fabricated system. The humidity sensing study of the synthesized structure is carried out through a wide range of relative humidity (RH) levels range of 11-97%. The response and recovery times of the fabricated structure are found to be around 120 and 220s, respectively.