Large-area graphene coating via superhydrophilic-assisted electro-hydrodynamic spraying deposition

We present the capability of large-area graphene coating via superhydrophilic-assisted electro-hydrodynamic spraying deposition (SH-ESD) technology. In this paper, we detail the effect of hydrophilicity on depositing graphene sheets with electro-hydrodynamic spraying. The mechanism of graphene deposition is shown mathematically and experimentally. The resulting graphene coatings were characterized by scanning electron microscopy, optical profilometry, Raman spectroscopy, XPS, and UV-vis spectroscopy. Raman spectroscopy indicates that the conjugated sp2 carbon network is still restored in the SH-ESD graphene coatings. By SH-ESD technology, the deposition coverage is up to 90% on an area of 4.4 cm by 4.4 cm only after 10 min. We also demonstrated potential in vitro application of SH-ESD graphene coatings in photothermal ablation (PTA) therapeutic with near-infrared spectroscopy (NIR) light. This work shows the possibility of controlling morphology, thickness and coating performance and the capability of effective mass production by this low-cost and scalable SH-ESD method.