One-step synthesis of gold bimetallic nanoparticles with various metal-compositions

Synthesis of mono-dispersed nanofluids using solution plasma

“…(SPR) band appears as a result of the NPs formation. [7][8][9][10] The presence of KOH in the solution determines the formation of AuCl 2 (OH) 2 À anion. 24 The main reaction during the reduction of AuCl 4 is: 25…”

“…The plasma phase surrounded by the solution has approximately a volume of 1.25 Â 10 À7 m À3 which means a total number of electrons of 4.3 Â 10 15 electrons. This suggests that the reduction of the gold ion Au 3þ to neutral Au 0 is also produced in the liquid phase of plasma as: 9,10 …”

“…17 Electrons are considered to be responsible for the formation of the gold NPs in the gas phase of the SPP (reaction (1)). 7,8 and then the following works [9][10][11][12][13][14][15][16][17] reported that the reduction reaction occurs at the interface between the gas and liquid phase in the solution plasma, termed "the reaction field." In the reaction field, the radicals and electrons are highly reactive and responsible for the reduction reaction of the gold precursor (reaction (2)).…”

“…[4][5][6] Recently, our research group has proposed a new SPPmethod that produces NPs with controlled size-distribution, high dispersibility, allows various compositions, and surroundings in an aqueous solution. [7][8][9][10][11][12][13][14][15][16][17] Compared to the chemical methods SPP displays much shorter processing times (from a few minutes up to a several tens of minutes) takes place at room temperature and atmospheric pressure and uses only low energy plasma. The novelty of our SPP method is that the plasma operates in glow discharge limits that in turn offer a suitable medium to control the chemical reactions inside the solutions.…”

“…The novelty of our SPP method is that the plasma operates in glow discharge limits that in turn offer a suitable medium to control the chemical reactions inside the solutions. This is possible because the plasma generates hydrogen, hydroxyl and oxygen radicals, and also electrons The electrons are reducing the gold ion to a neutral atom without any reduction agent The SPP method is able to control the composition by using a combination of reduction reactions with simultaneous eroding of the electrodes, 10 and to control the size by tuning the surrounding chemistry of the gold NPs, [7][8][9] or by simply adjusting the solution temperature during the process In this research, small sized gold NPs directly synthesized in solution which display enhanced thermal conductivity and dispersion stability that are important for nanofluid applications.…”