In situ synthesis of copper nanoparticles encapsulated by nitrogen-doped graphene at room temperature via solution plasma

Abstract

An excellent corrosion protection for copper nanoparticles by nitrogen-doped few-layer graphene via solution plasma process.

Carbon Layer Formation on Hexagonal Boron Nitride by Plasma Processing in Hydroquinone Aqueous Solution

“…Many researchers have studied carbon synthesis and deposition on materials using plasma processes, including nanographene synthesis using alcohol in-liquid plasma. − Nitrogen-doped carbon has also been synthesized on metal nanoparticles using plasma in solutions containing organic compounds such as N,N -dimethylformamide. , Furthermore, as low-pressure plasma processes, various diamond-like carbons have been synthesized by plasma-enhanced chemical vapor deposition, − and the direct growth of graphene on hBN by plasma-assisted molecular beam epitaxy has been reported. , In our previous studies, the modification of hBN particles by plasma in hydroquinone aqueous solution was found to improve their dispersibility in water and a polymer matrix with maintaining the thermal conductive and electrical insulating properties as fillers, , but the surface state was not clarified.…”

Can graphene improve the thermal conductivity of copper nanofluids?

“…Since the synthesis methods of Cu@G NPs reported in the literature have produced multi-layer graphene shells for Cu NPs, 41,[46][47][48]53 the variation in the k concerning the number of layers per flake was studied and reported in Fig. 5.…”

“…Until now, the reported protocols consist of depositing C atoms on Cu NPs, eventually forming a graphene cover. 40,41,[46][47][48][49][50][51][52][53] However, to our knowledge, no techniques have been proposed to produce Cu@G NPs in steps, i.e., generating the Cu NPs and graphene flakes separately and then putting them together in a single medium. Our results suggest that, in these cases, it would not matter if the adsorption of the flakes on the NPs occurs planar one by one or if they first form a stack and then adsorb perpendicularly.…”

“…13 In addition, graphene-water NFs were investigated as heat sinks, resulting in an increment in the convective heat transfer that reached B84%; 37 in a heat pipe, graphene nanosheets were reported to enhance the k of water by B28%; 38 and even a greater improvement was quantified for ethylene glycol, where dispersed graphene increased the k by up to 86% at 5.0 vol%. 39 Although some studies have provided methods to produce Cu@G heterostructures, [40][41][42][43][44][45][46][47][48][49][50][51][52][53] their diameter, size distribution, shape, and the number of graphene capping layers remain uncontrollable. These properties depend on many factors, which are hard to manipulate during the synthesis process.…”

Insight on Solution Plasma in Aqueous Solution and Their Application in Modification of Chitin and Chitosan

“…The distance between the tips of electrodes in the HCl solution increased from 0.1 mm to 0.17 mm, while 0.12 mm and 0.15 mm were observed in the KCl and KOH solution, respectively. Accordingly, it suggested that acidity has a significant influence on the sputtering of metal electrodes in the SPP, which is considered as an advantage for the synthesis of metal-based nanoparticles without using precursors and reducing agents [ 32 , 38 , 57 ]. Furthermore, the investigation on the formation of • OH was also conducted via the time-resolved optical emission measurement at various time delays to the positive voltage pulse in the range of 0–38 μs.…”