Table 1.

Mode of synthesis and characteristics of commercially important nanoparticles (NPs).

NPs	Mode of Synthesis	Size (nm)	Characters	Ref *
Silver NPs	Litchi chinensis leaf extract	41–55	Crystalline nature	[50]
	Tube furnace	6.2–21.5	Spherical shape	[29]
	Laser ablation	20–50	Pentagonal one dimensional (1-D) nanorods, nanowires, cubic/triangular-bipyramidal nanocrystals	[30]
	Carboxymethylated chitosan with ultraviolet light irradiation	2–8	Cubic crystal structure	[40]
	Eucalyptus macrocarpa leaf extract	10–100	Spherical and cubic shaped	[51]
	Sodium borohydride	2–4	Nanorods	[63]
	Silver nitrate with sodium borate	20–50	Mixture of spherical and rod NPs	[39]
	Wet chemical method	20	Nanowires	[44]
	Ascorbic acid as a reducing agent	31	Spherical shaped	[45]
	Silver nitrate and methanolic Rhazya stricta root extract	20	Spherical shaped	[52]
Iron NPs	Leaf extract of barberry, Elaeagnus angustifolia, Ziziphus jujube	40	Spherical shaped	[53]
	Sodium borohydride	44.87	Spherical shaped	[40]
	Ferric chloride precursor with sodium borohydride	6	Spherical in shape	[40]
	Grape tree leaf extract	10–30	Spherical and non-agglomerated	[54]
	Green tea extract	40–60	Amorphous in nature, chain morphology	[55]
	Mesoporous silica	10–300	Uniform pore size, large surface area, high accessible pore volume	[46]
	Thermal dehydration	6–10	globular-shape crystallites	[32]
	Thermal decomposition	50	Irregular and not spherical	[33]
Zinc oxide NPs	Albizia lebbeck	66.25	Irregular spherical morphology	[56]
	Chamomile flower extract	48.2	Pure crystalline	[64]
	Ricinus communis seed extract	20	Crystalline hexagonal	[57]
	Ammonium carbamate	10–15	Crystallite rod-shape	[47]
	Aloe vera leaf extract	25–40	Highly stable and spherical	[58]
	Refluxing zinc acetate precursor in diethylene/triethylene glycol	15–100	Oval to rod shape	[48]
Copper NPs	Alcothermal method	6	High dispersion, narrow size distribution	[9]
	Sodium borohydride	17.25	Spherical shaped	[41]
	Thermal decomposition	15–30	Nearly spherical with relatively uniform diameters	[34]
	Biosynthesis by Morganella	15–20	Crystal lattice structure	[49]
	Sodium borohydride	15	Pure crystalline metallic phase with face centered cubic, rich in dents, irregular surface	[35]
	Polyol method	45	Pure crystalline with face centered cubic structure	[36]
	Ocimum sanctum leaf extract	77	Different organic molecules, high crystallinity	[59]
	Wet chemical synthesis involving stoichiometric reaction	9	Spherical	[43]
	Polyol method by copper acetate hydrate in tween 80	580	Crystalline nature	[37]
	Reduction of copper (II) acetate in water and 2-ethoxyethanol using hydrazine under reflux	6–23	Spherical	[40]
	Thermal reduction	200–250	Irregular particles	[42]
	Sonochemical reduction	50–70	Irregular network of small NPs	[42]
	Cassia alata flower extract	110–280	Aggregates with rough, particles, spherical	[60]
	Capparis zeylanica leaf extract	50–100	Cubical structure	[61]
	Syzygium aromaticum extract	5–40	Spherical and granular nature	[62]
Titanium oxide NPs	Ytterbium fiber laser ablation	25	Spherical and polycrystalline	[31]
	Taguchi method	18.11	Spherical	[65]
	Sol-gel method	15	Crystalline and nearly spherical	[66]

* Ref means references.