A new approach to surface activation of porous nanomaterials using non-thermal helium atmospheric pressure plasma jet treatment

Abstract

Non-thermal helium atmospheric pressure plasma jet treatment is applied to the surface activation of porous TiO nanoparticle assemblies. Treatment conditions such as the working distance of the plasma discharge, helium gas flow rate, and treatment time are optimized for effective removal of contaminants from the assembly surface. Laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF MS) is applied to detect trace amounts of contaminants on assembly surfaces. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations confirm that the nanoparticle assemblies retain their original perfect spherical structures as well as their ultra-fine convex-concave nano-surfaces even after the plasma jet treatment. N adsorption/desorption and X-ray diffraction (XRD) measurements show no significant changes in their BET specific surface areas and crystal structures, respectively. The plasma jet-treated TiO nanoparticle assemblies show a 3.8 fold improvement in their reaction rate constants for methylene blue degradation and a 2 fold enhancement of their photocurrents under UV irradiation when compared with untreated TiO.

He-Plasma Jet Generation and Its Application for E. coli Sterilization

“…In fact, RNS and ROS have been found to induce apoptosis in cancer cells [12]. Among different forms of NTP, the atmospheric pressure plasma jet (APPJ) is a promising technology for various applications, including modification of hydrophilic and chemically active materials [13], material surface etching [14], bacterial inactivation [15], skin disinfection [16], wound treatment [17], caries treatment [18], blood coagulation [19], and cancer cell apoptosis [20].…”

Mineralization of flexible mesoporous TiO2 photoanodes using two low‐temperature dielectric barrier discharges in ambient air

“…Plasma treatments of both DBDs led to changes in the chemical stoichiometry and morphology of the mesoporous photoanodes, resulting in a significant increase of the work function from approx. [10] Furthermore, deposition of TiO 2 from the liquid phase, which is suitable and popular for flexible organic substrates, requires a binder to hold the NPs together and to provide good mechanical stability and adhesion to the substrate. We also studied the effect of plasma mineralization on the photoelectrochemical properties of the flexible mesoporous TiO 2 photoanodes.…”

“…[2][3][4] TiO 2 NPs are in use as photoanodes in dye-synthesized solar cells (DSSCs), [5] and recently porous and/or compact TiO 2 layers are utilized in perovskite solar cells (PSCs). [10] In the authors' previous work, [32] dielectric barrier discharge (DBD) with the coplanar configuration of electrodes developed byČernák et al [33] was employed for mineralization of inkjet-printed mesoporous TiO 2 photoanodes on the Fluorine doped Tin Oxide (FTO) glass. [7][8][9] As the deposited NPs possess a large absorbing area, the TiO 2 layer is often contaminated by the adventitious organic impurities from the ambient environment.…”

“…[7][8][9] As the deposited NPs possess a large absorbing area, the TiO 2 layer is often contaminated by the adventitious organic impurities from the ambient environment. [10] Furthermore, deposition of TiO 2 from the liquid phase, which is suitable and popular for flexible organic substrates, requires a binder to hold the NPs together and to provide good mechanical stability and adhesion to the substrate. However, the adventitious impurities and/or organic moieties from the binder affect the performance of deposited coatings in practical applications e.g.…”

“…[17] Very recently, a helium APP micro-jet has been employed for the activation of porous TiO 2 where the photocatalytic activity of TiO 2 significantly improved. [10] In the authors' previous work, [32] dielectric barrier discharge (DBD) with the coplanar configuration of electrodes developed byČernák et al [33] was employed for mineralization of inkjet-printed mesoporous TiO 2 photoanodes on the Fluorine doped Tin Oxide (FTO) glass. [32] Consequently, the photoelectrochemical activity of the photoanodes increased significantly.…”