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.