Design and implementation of low-cost gas sensor based on functionalized graphene quantum dot/Polyvinyl alcohol polymeric nanocomposites

Polyvinyl Alcohol’s (PVA) Electronic Properties are improved by adding metal oxides and functional groups, allowing them to be used in various applications based on their electrical properties. As a result, the functionalization of PVA is modeled using density functional theory at M062x/6–311 + G(2d, p). As an adsorption state, five molecules with various functional groups bind with the PVA surface: hydroxyl group (OH), carboxyl group (COOH), cyanide (CN), amino group (NH₂), and graphene quantum dots (GQDs). As a result, there is a shift in the overall dipole moment and the HOMO/LUMO bandgap energy. Also investigated is the molecular electrostatic potential (MESP). Because of the functionalization, the possibility of PVA creating hydrogen bonds with its surroundings is increased. Also, the molecular electrostatic potential (MESP) is investigated. Because of the functionalization, the possibility of PVA making hydrogen bonds with its surroundings is increased, as seen by the MESP maps. The PVA surface’s physical properties fluctuate, making it suitable for various applications. Finally, the researched structure was dedicated as a gas sensor using the proposed model of PVA functionalized with GQDs.