Novel self-assembled graphene oxide coating by atmospheric pressure plasma jet

A new and simple method of deposition of graphene oxide-based coatings using an atmospheric pressure plasma jet is reported in this work. This new deposition method incorporates an ultrasonic fog of graphene oxide aqueous solution towards the plasma zone. The morphological, chemical, optical, and electrochemical properties of the coating were studied. The results show that the deposition process is based on the fact that plasma evaporates the water from the fog and projects the graphene oxide particles toward the substrate, forming a coating that grows proportional to the time of exposure to the plasma jet. The coatings obtained by this novel method are homogeneous, continuous, and with the characteristics of graphene oxide. The chemical studies show that plasma deposition did not introduce new chemical species into the coating and the functional groups of graphene oxide did not change when exposed to plasma. We propose that the peripheral OH functional groups were released by passing through the plasma, leaving charged edges that interact with other laminar particles. The particles constructed an ensemble in the horizontal and vertical directions. In the thermogravimetric analysis, the GO coating presented differences compared to graphene oxide without treatment by plasma. These differences are based on the amount of water and oxygen pyrolysis. Optically, this new coating showed about 80% absorbance in a wavelength range from 400 nm to 2000 nm and about 90% reflectance in 2500–15000 nm. This is near the performance of selective absorption coatings and promising for harvesting solar energy. Furthermore, the coating has an electrochemical behavior characteristic of graphene oxide obtained by other methods, which are based on the reduction-oxidation of GO. © 2024 Elsevier Ltd