Table 1.
Recent examples of “wet syntheses” in DES media.
| Solvent | Reagents/Path | Product | References |
|---|---|---|---|
| ChCl:urea 1:2 | Preparation of separate solutions of HAuCl4⋅4 H2O (0.015 g) and L-ascorbic acid (LA, 0.05 g) in DES. Addition of LA solution to HAuCl4 at 30 °C under magnetic stirring until the color changes from yellow to dark purple |
Au nanoparticles Star, snowflake, or nano-thorn-shaped depending on water content |
[49] (Figure 2) |
| Direct electrodeposition on GC substrate in 19.3 mM H2PtCl6/DESs solution at 80 °C | Tetrahexahedral (THH) concave Pt NCs | [52] | |
| Triambic Icosahedral Pt NCs | [54] | ||
| Mixing CuCl2·2H2O (5.0013 g, 0.0293 mol) and Cu powder (1.6935 g, 0.0265 mol) with DES, gentle stirring at 20 °C for 5 h, rinsing with diluted HCl | CuCl nanocrystal powder | [56] | |
| Addition of 2.2232 g of CuCl2 2H2O and 1.3754 g of ascorbic acid to 14 mL DES in the presence of PVP, mild stirring at 25 °C for 1 h, rinsing with 50 mL HCl (0.1 M) | Spherical CuCl nanoparticles | [57] | |
| Addition of 2.164 g (8 mmol) FeCl3·6H2O and 1.194 g (6 mmol) FeCl2·4H2O to 15.585 g DES, stirring at ca. 600 rpm and 80 °C for 20 min, subsequent addition of 2.613 g (46.7 mmol) KOH, and stirring for another 1.5 h at 80 °C. Alternatively, see Figure 5 and last paragraph | Spherical, magnetic Fe3O4 nanoparticles | [58]; Figure 5 and last paragraph | |
| Solvent: 35.70 g of DES (30 mL at 37 °C) and 6 mL of water. Dissolution of thioacetamide (TH, 12 mmol, 0.9134 g) mL into 12 mL of solvent and lead (IV) acetate (LAC, 12 mmol, 5.3206 g) into the remaining liquid, stirring of both solutions at 80 °C. Injection of TH into LAC changes the solution from pale yellow to opaque dark brown. Rinsing with water, followed by dialysis, centrifugation, and drying in furnace at T ≤ 80 °C | Hyperbranched PbS Nano/microcrystals | [59] | |
| Heating of NiCl2·6H2O in DES (0.1 M solution) at 150 °C for 40 min; then addition of 10 mL of water and further stirring for 20 min, cooling in ice bath; drying of precursor overnight at 90 °C and further annealing in air (300 °C) for 4 h | Mesoporous NiO | [60] | |
| NiCl2·6H2O in DES ionothermal reactions at different temperatures and conditions | Ni(NH3)6Cl2, NiCl2 and nanoflower-like α-Ni(OH)2 and NiO | [61] | |
| Dissolution of 5.94 g of Ni(H2PO2)2·6H2O (0.02 mol) and 1.66 g of NH4H2PO2 (0.02 mol) in 27.92 g (0.2 mol) of choline chloride and 24.02 g (0.4 mol) of urea, stirring at 323 K under N2 for 30 min, reduction of product with H2 at 673 K for 3 h | Ni2P supported on amorphous/mesoporous Ni3(PO4)2-Ni2P2O7 | [62] | |
| Emulsion of 2.25 g SnCl2·2H2O in 100 mL DES. Variable reaction times (1 to 60 min) | Nano-sized SnO particles (20–30 nm) | [63] | |
| Heating of 40 mL of 0.1 M FeCl3·6H2O/DES solution at 200 °C, after 10 min. addition of 40 mL of water and further reaction for 10 min. Washing of precipitate with ethanol and dried at 80 °C overnight | Fe2O3 nanospindles | [64] | |
| Dissolving CoCl2·6H2O into ChCl to obtain a 0.1 M CoCl2:ChCl solution, addition of 100 mL of water after heating for 40 min at different temperatures. Subsequent ice bath cooling, rinsing of product with water and methanol, and drying at 70 °C under vacuum | Mesoporous Co3O4 sheets or nanoparticles | [65] | |
| DES solution of bulk ZnO. Precipitation with water (anti-solvent approach) |
ZnO nanocrystals doped with Cu(II) ions | [67] | |
| Dissolution of SnCl2·2H2O in DES, stirring in pre-heated water bath (50, 80, 98 °C), precipitation with ethanol, and drying at 230 °C | SnO2 nanoparticles | [68] | |
| Mixing of y mmol NiCl2 6H2O and 20-y mmol CoCl2 6H2O (y = 0, 2.5, 5, 10) in 10 mL DES. Addition of 1 mmol SDS and 20 mL water, heating for 12 h at 100 °C, washing of precipitate with water and ethanol | NixCo2-x(OH)3Cl | [91] | |
| Stirring of 1.668 g (0.006 mol) FeSO4·7H2O and 0.584 g (0.010 mol) of KOH 0.408 g in DES for 30 min, addition of 0.408 g (0.0012 mol) tetrabutyl titanate (TBOT) and 0.420 g (0.008 mol) of KOH, stirring first at 80 °C (30 min) and then at 110 °C (4 h), washing of precipitate with water and ethanol | Fe2.5Ti0.5O4-DES nanoparticles | [93] | |
| ChCl:urea 1:2 ChCl:urea:water 1:2:10 |
Hydrothermal treatment of Fe(NO3)3·9H2O/DES mixtures (dry and hydrated DES) for 3–8 h at 90 °C before particles are dried at 60 °C from ethanol after dialysis | FeO | [88] |
| Dissolution of Ce(NO3)3·6 H2O in DES and stirring at 250 rpm for 40 min, reaction in pressurized continuous microreactor at 100–160 °C, washing of the solid product with water and ethanol and drying at 80 °C | CeO2 | [89] | |
| (CH3)NH2 HCl:urea 1:1.5 | Mixture of Sn (0.119 g, 1.0 mmol), Se (0.211 g, 2.67 mmol), dimethylamine hydrochloride (0.58 g, 7.1 mmol), urea (0.64 g, 10.67 mmol), and 0.3 mL of N2H4·H2O (98%) (∼6.17 mmol), hydrothermal synthesis at 160 °C (3 h), rinsing with water | Silver and selenido-stannates [NH4]3AgSn3Se8 [NH4]2Sn4Se9 [NH3C2H5]2Sn3Se7 | [82] |
| ChCl:oxalic acid 1:1 | Dissolution of 30 mg of commercial Fe3O4 in 1 mL ChCl/OA DES at 50 °C by ultrasonic treatment, microwave heating for 10 s at 100 W, further thermal treatment at 300 °C for 2 h | Fe3O4 nanosheets | [117] |
| Addition of MgO and α-Fe2O3 to DES molar ratio 1:1 (0.5 wt% melt in the overall amount of metal oxides), stirring for 1 h, then calcination of melts at 500 °C for 1 h (5 °C min–1 heating rate) | MgFe2O4 nanoparticles | [115] | |
| ChCl:acrylic acid | Stirring of ChCl and MAA in the molar ratio 1:2 at 80 °C; mixing with a porogen (MeOH), initiator (AIBN), crosslinking agent (EGDMA), and template (levofloxacin); heating at 60 °C for 12 h; removal of template by Soxhlet extraction with methanol | Levofloxacin-imprinted Pd nanoparticles | [75] |
| ChCl:oxalic acid:water 1:1:1 | Mixing of cellulose pulp (0.5 g) with DES (10 g) and water (10 g), heating at 110 °C for 2 h in a Teflon-lined reactor to obtain carboxylic cellulose (CNF). Addition of 10 mL of PdCl2 (17.7 mg) in HCl and aqueous NaBH4 (10 mg, 1 mL) to a diluted CNF suspension (20 mL, 0.4 wt%), reaction at 4 °C for 4 h, separation of Pd NPs by dialysis | Pd nanoparticles confined in nanocellulose | [116] |
| ChCl:ethylene glycol 1:2 | Mixing of NiSO4·6H2O (0.1 M), Na2S2O3·5H2O (0.1 M), EDTA (0.06 M), and DES in a beaker at different temperatures (80 °C, 100 °C, 110 °C, 120 °C, 160 °C); stirring of the mixtures for 3 h; washing of the solids with water and ethanol; and drying at 60 °C | NiS2 nanospheres | [101] |
| Dissolution of 4.0 mg of Pt(acac)2, 40 mg PVP, and 25 mg of SDS in 8 mL DES; heating in oil bath at 130 °C for 2 h; washing of the black precipitate with ethanol | Pt hollow-opened structures | [105] | |
| ChCl:glycerol 1:2 | Hydrothermal heating of ZrCl4, BDC (1,4 benzene dicarboxylate), H2O, and DES at a molar ratio of 1:1:1:500 at 120 °C for 48 h; washing of the solid with water | Nanoparticles containing ZrCl4 | [107] |
| Mixing 2.19 g of Zn(CH3COO)2·2H2O and 0.2 g of graphene in 50 mL DES, precipitation with 0.8 g NaOH | ZnO in situ on graphene sheets | [109] | |
| ChCl:CaCl2 1:2 | CO2 capture from air of CaCl2·6H2O and choline chloride DES at 50 °C under stirring at 400 rpm, formation of CaCO3 sediment after 6 h, washing of the sediment with water, drying at 60 °C for 12 h, reuse of the filtrate for further CO2 capture | CaCO3 NPs | [78] |
| ChCl:glucose/fructose/sucrose/maltose/raffinose | Liquid-phase exfoliation of MoS2 in glucose, fructose, sucrose, raffinose, maltose, choline chloride, and water DES at various ratios (5 mg MoS2 per mL of DES); separation of exfoliated material in ethanol/water | MoS2 nanosheets | [77] |
| CHCl:glucose | DASH: Dopamine hydrochloride (DA), N-Hydroxysuccinimide (NHS), 1-ethyl-3-(3-(dimethylamino)propyl) carbodiimide (EDC), sodium hyaluronate (SH) in 2-(N-morpholino) ethanesulfonic acid-buffered solution (MES buffer). Addition of AgNO3 to DES-DASH 4:175 mixture | Na hyaluronate/dopamine/Ag NPs hydrogels | [111] |
| ChCl:xylitol 1:1 | Mixing 0.2 g Fe3O4@TiO2 nanoparticles and 3.0 mL [ChCl][Xyl] by ultrasonication for 2 h, separation by external magnet, rinsing with water | Fe3O4@TiO2@DES | [112] |
| ChCl:gluconic acid | Mixing 2 g choline chloride, 4 g urea, and 0.4 g Co(NO3)2·6H2O in 5.62 mL of 50% gluconic acid solution; calcination in N2 at 700–900 °C after freeze-drying | Co@NPC | [113] |
| CHCl:citric acid 2:1 | Addition of 3.9813 g FeCl2 4H2O (20 mM) and 8.1091 g of FeCl3.6H2O (30 mM) at the molar ratio 1:1.5 to DES, stirring at 80 °C (600 rpm) for 20 min, addition of 40 g (712.94 mM) KOH, stirring for another 1 h, washing with ethanol and water | Fe3O4 nanocubes | [122] |
| Betaine-urea 1:2 | DES: betaine (2.343 g) and urea (2.4 g), heating for 15 min at 125 °C, addition of 1.5 mL water, dissolution of 0.111 g FeSO4·7H2O (0.4 mmol) and 0.216 g FeCl3·6H2O (0.8 mmol) in DES at RT under stirring (10 min), precipitation by the addition of 0.2 g of KOH (3.5 mmol), separation with external magnet, and washing with water | Nano-Fe3O4 Nano-Fe3O4@SiO2–NH2 |
[121] |
| BTAB/BTBAC/TBAC:lactic acid | [BTBAC][Lac]-DES: Mixing 3.12 g BTBAC and 1.80 g Lac at a molar ratio 1:2 under heating at 80 °C in oil bath for 1 h. Addition of 2.0 mL DES to a phosphate buffer (20 mM, pH = 7.0) containing 0.24 g of NHS and 0.16 g of EDC·HCl to activate the carboxyl group of DES; subsequently, the addition of 0.20 g MUiO-66-NH2, stirring for 12 h, washing of particles with water, and freeze-drying | Fe3O4-MUiO-66-NH2 | [124] |
| TBAB:imidazole | Condensation of TFPT (main building block) and hydrazine (comonomer) in BuN4Im/Br at 90 °C for 12 h, subsequent impregnation with Pd(oAC)2 under reflux | Pd@MOF | [125] |
| CTAB:acetic acid 1:1 | Mixing cetyltrimethylammonium and acetic acid at 70 °C for 3 h. Addition of 1 g ammonium cerium (IV) nitrate to 0.5 g of DES and hydrothermal treatment of the solution at 130 °C for 7 h. For N-doping, a urea solution (10 g/30 mL of water) is added, followed by the separation of particles by centrifugation and washing with ethanol and acetone | Plain and N-doped CeO2 | [126,127] |
| dl-menthol:oleyl alcohol 1:1.2 | Mixing 1 mol D,L-menthol and oleyl alcohol at 343.15 K under stirring for 12–24 h. Addition of h-BN nanoparticles at different weight percentages, shaking, and sonication for 2 h | BN nanoparticle nanofluid | [128] |
| Acetic acid:menthol 1:2 pyruvic acid:menthol 1:1 lactic acid:menthol 1:2 lauric acid:menthol 2:1 | Mixing of D,L-menthol with PA, AA, LacA, or LauA at 50 °C for 15 min before drying under vacuum (10−1 Pa). Preparation of high-internal-phase emulsions (HIPEs) by dropping DES into a continuous phase of AAm:BAAm (acrylamide:N,N′-Methylenebis(acrylmide), polymerization with potassium persulfate (KPS), and coating with γ-Fe2O3 | Polyacrylamide γ-maghemite composites | [120] |
| Acrylic acid:mentho 1:2 | Mixing AA and menthol at 70 °C in a water bath for 5 min, polymerization of DES via a thermal frontal method usingFe3O4 NPs-AA as a cross-linker and thermal initiator into a magnetic poly (AA-menthol DES) hydrogel | Acrylic acid:Fe3O4 composites | [119] |
| Choline:Na2SO3 2:1 | Heating of 7.0 g of choline chloride and ∼4.0 g NaS2O3 in 2:1 molar ratio at 40 °C for 3 h. Addition of 16 mL DES to a GO solution in the presence of hydrazine as a reducing agent, co-precipitation of reduced GO and sulfur | Sulfur-functionalized graphene oxide NPs | [118] |
| Dimethylammonium nitrate:triethylene/ethylene glycol, or glycerol 1:1 | HBA: Addition of 119.4 mL of 5.0 N HNO3 solution (0.597 mol) to aqueous dimethylamine (40 wt% in H2O, 0.597 mol). HBD: triethylene glycol, ethylene glycol, or glycerol. Addition of HAuCl4 or AgNO3 and oleylamine (OAm) (reducing agent) in each DES under stirring (150 rpm); heating at different temperatures (12 h at 60 °C for Ag, 19 min. 140–170 °C for Au) |
Ag or Au colloidal nanocrystals | [81] |