Influences of Plasma Plume Length on Structural, Optical and Dye Degradation Properties of Citrate-Stabilized Silver Nanoparticles Synthesized by Plasma-Assisted Reduction

Abstract

Citrate-capped silver nanoparticles Ag@Cit NPs were synthesized by a simple plasma-assisted reduction method. Homogenous colloidal Ag@Cit NPs solutions were produced by treating a AgNO3-trisodium citrate-deionized water with an atmospheric-pressure argon plasma jet. The plasma-synthesized Ag@Cit NPs exhibited quasi-spherical shape with an average particle diameter of about 5.9−7.5 nm, and their absorption spectra showed surface plasmon resonance peaks at approximately 406 nm. The amount of Ag@Cit NPs increased in a plasma exposure duration-dependent manner. Plasma synthesis of Ag@Cit NPs was more effective in the 8.5 cm plume jet than in the shorter and longer plume jets. A larger amount of Ag@Cit NPs were produced from the 8.5 cm plume jet with a higher pH and a larger number of aqua electrons, indicating that the synergetic effect between plasma electrons and citrate plays an important role in the plasma synthesis of Ag@Cit NPs. Plasma-assisted citrate reduction facilitates the synthesis of Ag@Cit NPs, and citrate-capped nanoparticles are stabilized in an aqueous solution due to their repulsive force. Next, we demonstrated that plasma-synthesized Ag@Cit NPs exhibited a significant degradation of methylene blue dye.

Antimicrobial efficacy of direct air gas soft jet plasma for the in vitro reduction of oral bacterial biofilms

“…The frequency, electrical energy and power of the plasma were 85 kHz, 0.18 J/s and 1.8 W, respectively. The plasma generated energy, and dissipated power were calculated using the following equations 39 , 40 :

Figure 1 Illustration depicting the configuration of a soft jet plasma ( A ), current–voltage characterization of the soft jet plasma ( B ), electrical properties of the soft plasma jet ( C ), optical emission spectra of the soft plasma jet ( D ).

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“…The NO X spectrum was examined within the wavelength range of 200–280 nm, revealing the presence of OH radicals emitting at 309 nm. The emission attributed to the nitrogen second positive (N 2 SPS) was observed in the 311–380 nm region 40 . Furthermore, within the range of 390–410 nm, the First Negative System (FNS) of nitrogen (N 2 ) emission was observed.…”

Cold atmospheric plasma activated media selectively affects human head and neck cancer cell lines

“…1C). Duty ratio, energy generation, power dissipation for the plasma were calculated using the following equations (1-3) [32,33].…”

Silver Nanoparticle Synthesis in Glycerol by Low-Pressure Plasma-Driven Electrolysis: The Roles of Free Electrons and Photons

“…Through computational studies, we reveal that glycerol can undergo photodissociation of the O−H bonds for incident photon energies of >5 eV, forming various radicals, e.g., hydrogen radicals (H•, with a standard redox potential of −2.3 V), that then exhibit the ability to reduce silver ions (Ag + + H• → Ag 0 + H + ). 28,29 In this study, to differentiate among different plasma species such as electrons, ions, metastables, and UV photons, optical filters were introduced between the plasma and the droplet of the Ag/glycerol electrolyte solution, as depicted in panels a and b of Figure 1. The relevant experimental setup is described in section S1 of the Supporting Information.…”

“…We find that photons with energies as low as 5 eV deliver an important contribution to NP production, resulting from the fragmentation of glycerol upon UV irradiation composed of these comparatively low-energy photons. Through computational studies, we reveal that glycerol can undergo photodissociation of the O–H bonds for incident photon energies of >5 eV, forming various radicals, e.g., hydrogen radicals (H•, with a standard redox potential of −2.3 V), that then exhibit the ability to reduce silver ions (Ag + + H• → Ag 0 + H + ). , …”