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

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 N-2/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 degrees for the reference TiO2 powder to <5 degrees 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.

Automated summary

A one-step technique was used to deposit superhydrophilic TiO2@carbon nanocomposites, resulting in a drastic reduction in water contact angle. This effect was attributed to the increased density of graphitic compounds at the surface, rather than an increase in surface roughness, as confirmed by X-ray photoelectron spectroscopy measurements.