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

Abstract

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.

Hierarchical Structures Formed in an Atmospheric Pressure Plasma Jet by Polymerization from an Aerosol of Oxalic Acid Stabilized WO3–x Nanosheet Colloids: Toward High-Performance Electrochemical Devices and Sensors

“…Furthermore, individual aerosol droplets may act as microreactors, where the droplet is a controlled environment of known size and composition. − Coupled with colloidal chemistry, which enables the preparation of complex precursor mixtures, aerosol-assisted plasma processing promises to be a viable technique for the deposition of highly tailored microstructures. Indeed, several groups have previously reported the deposition of nanocomposite and inorganic/organic hybrid films from colloidal feedstocks utilizing dielectric barrier discharge (DBD) plasma reactors. − These works focused primarily on the deposition of TiO 2 and ZnO films from colloidal suspensions of preformed nanoparticles. Interestingly, the plasma-deposited films are often composed of spherical aggregates of smaller particles, attributed to evaporation-induced agglomeration arising from aerosol–plasma interactions.…”

Low-Temperature Atmospheric Pressure Plasma Processes for the Deposition of Nanocomposite Coatings

“…The above discussion about the fundamental mechanisms that control the growth of the matrix and the transport of the NPs to the substrate surface can facilitate the understanding of the studies which explored the influence of various process parameters on the chemical composition and morphology of the deposited coatings. These studies can be divided into two classes: the first investigated the influence of the composition of the starting NPs dispersion [32,60,124,125,132]; and the second explored the effect of the electrical conditions used to generate and sustain the DBD [62,64,128,129,133].…”

“…surface is promoted; in contrast, at greater concentration of octadiene (>2 vol%), the growth of the organic component is favored. A number of recent studies demonstrated the possibility of tuning the properties of the NC coatings by simply varying the electrical parameters utilized for DBD generation, such as the excitation frequency [62,64], the waveform [62,128,129] and the amplitude [133] of the voltage applied to the electrodes. In particular, the works by the Massines [64,128,129] and Gherardi groups [62] on the influence of the excitation frequency, the applied voltage waveform, and the modulation mode are of great conceptual importance.…”

“…Results revealed that, at low frequency (1-10 kHz) (Figure 6a), the transport of NPs to the surface is favored due to the electrostatic force and dominates over isopropanol plasma polymerization. In contrast, by increasing the frequency from 10 to 50 kHz (Figure 6a), the growth rate of the organic component increases because of the increase of the plasma power, while the NPs A number of recent studies demonstrated the possibility of tuning the properties of the NC coatings by simply varying the electrical parameters utilized for DBD generation, such as the excitation frequency [62,64], the waveform [62,128,129] and the amplitude [133] of the voltage applied to the electrodes. In particular, the works by the Massines [64,128,129] and Gherardi groups [62] on the influence of the excitation frequency, the applied voltage waveform, and the modulation mode are of great conceptual importance.…”