Atmospheric plasma dielectric barrier discharge: A simple route to produce superhydrophilic TiO2@carbon nanostructure

• Published in: Plasma processes and polymers Vol. 18; no. 3
• Main Authors: Matouk, Zineb, Torriss, Badr, Rincón, Rocío, Mirzaei, Amir, Margot, Joëlle, Chaker, Mohamed
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.03.2021
• Subjects: atmospheric pressure; Atomic force microscopy; Carbon; Contact angle; core−shell nanostructures; Dielectric barrier discharge; Gas mixtures; Hydrophilicity; Nanocomposites; Nanoparticles; Photoelectrons; superhydrophilicity; surface functionalization; Surface roughness; Titanium dioxide; Wettability
• ISSN: 1612-8850; 1612-8869
• DOI: 10.1002/ppap.202000173

A one‐step technique for the deposition of superhydrophilic TiO2@carbon nanocomposites is described in this study. The nanocomposites are synthesized by injecting TiO2 nanoparticles suspended in isopropanol into a dielectric barrier discharge operating at atmospheric pressure (AP‐DBD) generated in an N2/N2O gas mixture. The influence of the voltage (3–8 kV) applied to a 2‐kHz‐operated AP‐DBD on the wettability of the as‐deposited TiO2@C nanocomposites is examined. The water contact angle is drastically reduced from 93° for the reference TiO2 powder to <5° for the deposited nanocomposite. This superhydrophilicity is not caused by the increase of the surface roughness determined by atomic force microscopy measurement but rather by the higher density of graphitic compounds at the surface, as confirmed by X‐ray photoelectron spectroscopy measurements. This study reports the synthesis of TiO2@carbon nanocomposites using a scalable and one‐step plasma process that can operate at low temperature. A thorough characterization of the wettability properties, composition, morphology, and structure of the films shows the achievement of TiO2@C nanocomposites. Depending on the voltage applied to the dielectric barrier discharge (DBD), there is a significant change in the wettability and morphology properties of TiO2‐based nanocomposites with only a slight variation in their chemical composition. In particular, superhydrophilic TiO2@C nanocomposites are obtained at high voltage. This emphasizes that DBDs allow the synthesis of hybrid composites with tunable surface functionalities and properties.