Table 1.

A list of published methods to synthesize copper NPs by chemical reduction in solution.

#	Solvent	Cu precursor	Reducer	Stabilizer	Particle size	Ref.
1	Water	CuSO4	Sodium borohydrate	SDS	2–10 nm	Lisiecki 1996 [24]
2	Water + n-hexanol/cyclohexane	CuCl2	Sodium borohydrate	TX-100	5–15 nm	Qi 1997 [5]
3	Water+ n-Heptane, n-Octane, n-Hexane	CuCl2	Sodium borohydrate	HDEHP	40–80 nm	Song 2004 [25]
4	Isooctane	Cu(AOT)2	Hydrazine	Na AOT	10–30 nm	Salzemann 2004 [26]
5	Water	CuCl2	Hydrazine	CTAB	5 nm	Wu 2004 [27]
6	Ethylene Glycol	CuSO4	Ascorbic acid	PVP 40	100 nm (cubes)	Wang 2006 [28]
7	Water	Cu(NO3)2	Ascorbic acid	PVP 58	3 nm	Wu 2006 [29]
8	Di-Ethylene Glycol	CuSO4	Sodium phosphinate	PVP 40	45 nm	Park 2007 [7]
9	Octyl ether	Cu(acac)2	1,2-hexadecanediol	Oleic acid, oleyl amine	5–200 nm	Mott 2007 [30]
10	Toluene + water	CuCl2	Sodium borohydrate	Lauric acid + TOAB	3 nm	Kanninen 2008 [31]
11	Di-Ethylene Glycol	CuCl2	SFS	PVP	50 nm	Khanna 2009 [32]
12	Water	Cu(NO3)2	Hydrazine	PAA Na	20–100 nm	Grouchko 2009 [21]

SFS = sodium formaldehyde sulfoxylate; HDEHP = Bis(ethylhexyl)hydrogen phosphate; SDS = Sodium dodecyl sulfate; Na AOT = Sodium bis(2-ethylhexyl) sulfosuccinate; CTAB = Cetyl trimethylammonium bromide; PVP = Polyvinylpyrrolidone; TOAB = Tetraoctylammonium bromide; PAA Na = Polyacrylic acid sodium salt.