Hydrophobic behaviour of reduced graphene oxide thin film fabricated via electrostatic spray deposition

Graphene-based materials such as graphene oxide (GO) and chemically reduced graphene oxide (rGO) thin films have been fabricated using electrostatic spray deposition (ESD), followed by thermal annealing under Ar/H2 atmosphere. The thickness and surface morphology of thin films of GO and rGO on silicon substrates were controlled by varying deposition time and content of GO/rGO in tetrahydrofuran (THF) solution. Here, we present a comparative analysis between GO and rGO thin films. Water contact angle (WCA) measurements of these thin films were ~88° for the GO films and >127° for the rGO films. We discuss how their hydrophobic behaviour is influenced by removal of oxygen-containing functional groups during the reduction process.