Inkjet-Printed Reduced Graphene Oxide (rGO) Films For Electrocatalytic Applications

Abstract

Reduced graphene oxide (rGO) films for application as electrocatalyst have been deposited using an inkjet materials printer, with excellent control over the film morphology and properties. The dispersions were prepared by the ultrasound-assisted liquid exfoliation method using polyvinylpyrrolidone (PVP) as stabilizer. The environmentally friendly ink formulation exhibits a stability for at least 6 months. The inkjet-printed rGO/PVP composite films were thermally treated at different temperatures, and it was found that the fraction of remaining PVP considerably affects the final structural, textural, optical and electrocatalytic characteristics. After annealing at 400°C, the rGO film exhibits a morphology of interconnected flakes and a very good transparency with a transmittance >90% in the entire visible spectrum. The inkjet-printed rGO films have been applied as electrocatalytic coating on fluorine-doped tin oxide (FTO) and tested for activity for the reduction of Co(bpy)33+ in acetonitrile. Dye-sensitized solar cells (DSSCs) fabricated with an rGO film on FTO annealed at 400°C as counter-electrode achieved 87% of the efficiency with respect to DSSCs with a Pt-catalyzed counter electrode. Hence, the fabrication of active and inexpensive rGO films using a high-throughput technique such as inkjet printing is an interesting approach to accelerate the development of competitive electrocatalytic nanomaterials.