He/H2 Pulsed-Discharge Plasma as a Tool for Synthesis of Surfactant-Free Colloidal Silver Nanoparticles in Water

Abstract

In this study we investigated the interaction of atmospheric-pressure helium (He) and He/ H 2 pulsed-discharge plasma with different water solutions. We developed a synthetic path to obtain fairly uniform, small (~2 nm), surfactant-free silver (Ag) nanoparticles (NPs) with the treatment of an AgNO 3 solution with He/H 2 bipolar pulsed discharge. The colloidal solutions containing Ag NPs are stable for months negatively charged hydroxide (OH) ions on the surface of Ag NPs could be responsible for the electrostatic stabilization. The treatment of the air-saturated water by pure He plasma with a negative polarity leads to the creation of HNO 3 and hydrogen peroxide (H 2 O 2 solution by He plasma treatment, He/H 2 discharge with negative and, in particular, with bipolar pulses produces only traces of HNO 3 and no H 2 O 2. We demonstrate here that He/H 2 discharge with bipolar pulses 3 and KNO 3 solutions.

Oxygen Electroreduction on Pt Nanoparticles Deposited on Reduced Graphene Oxide and N‐doped Reduced Graphene Oxide Prepared by Plasma‐assisted Synthesis in Aqueous Solution

“…[61,62] The powder of as-prepared GO was dispersed in water by sonication for 30 min, then centrifuged (2500 g, 15 min) to precipitate the non-exfoliated large GO flakes. rGO and rGOÀN supported PtNPs were synthesized by a method similar to that described in our previous work [63]. For comparison a powder of nitrogen-doped reduced graphene oxide (rGOÀN) (Graphitene Ltd., UK) was used.…”

“…rGO and rGOÀN supported PtNPs were synthesized by a method similar to that described in our previous work [63]. An atmospheric pressure bipolar pulsed discharge in He/H 2 (95/5) gas jet with a continuous gas flow of 100 standard cubic centimeters per minute (sccm) was used for the net transfer of the plasma active species into the aqueous solution of 0.1 mM of H 2 PtCl 6 with small additives of rGO or rGOÀN.…”

“…[63,64] The pH values of solutions were measured by a portable pH meter (pH-98103R, Analytical Instruments). The voltage and current waveforms of the discharge were similar to that demonstrated in our previous works.…”

“…The voltage and current waveforms of the discharge were similar to that demonstrated in our previous works. [63,64] The pH values of solutions were measured by a portable pH meter (pH-98103R, Analytical Instruments).…”

Plasma-liquid synthesis of silver nanoparticles and their antibacterial and antifungal applications

“…The plasma-liquid interactions technique for the synthesis of nanoparticles is comparatively new. Different configurations of these methods depending upon power sources and electrodes have been used for the growth of silver nanoparticles [32][33][34].…”