Silver nanoparticles synthesis using H2 as reducing agent in toluene–supercritical CO2 microemulsion

Chemistry in supercritical fluids for the synthesis of metal nanomaterials

“…8a). 176 As W was gradually increased from 4, 6, 8 to 10, the size of Ag NPs became increasingly larger and was 2.5 nm, 4.1 nm, 5.3 nm and 6.3 nm, respectively (Fig. 8b).…”

“…The versatility of using supercritical CO2 in the development of metal nanomaterials has been shown in various forms, including (1) the synthesis and CO2-assisted synthesis of monodispersed metal NPs, in both the bottomup 51,[87][88][89]91,[98][99][100][101]107,118 and top-down 119,120 ways, (2) micelles dispersed in supercritical CO2 as 'nano-reactors' for the growth of metal NPs, [168][169][170][171][172][173][174][175][176][177][178] (3) template growth of robust metal nanostructures (nanofilms, 60,62,[179][180][181][182][183][184][185][186][187][188][189][190][191] nanowires, nanotubes [192][193][194][195] and porous nanostructures [196][197][198], and (4) deposition and immobilization o...…”

“…Using water-in-supercritical CO2 microemulsions with aqueous cores however enriches the choice of metal precursors available for the reductive synthesis of metal NPs in supercritical CO2, since inorganic precursors soluble in water but insoluble in supercritical CO2 can be used, as shown in the synthesis of Pt, Pd, Ag and Cu NPs. [168][169][170][171][172][173][174][175][176][177][178] For instance, Pd NPs of 5-10 nm were prepared by the method of water-in-supercritical CO2 microemulsions from aqueous Pd 2+ reduced by H2 in supercritical CO2 (50 °C, 20 MPa). 175 The water-to-surfactant molar ratio W that controls the size of aqueous cores (micelles) in a proportional way 168 can be used to control the size of metal NPs since the nucleation and growth occur within the cores.…”

Review on metal nanoparticles as nanocarriers: current challenges and perspectives in drug delivery systems

“…This can be attained by a high degree of supersaturation followed by nuclei growth [ 29 , 30 ]. By considering these two approaches, various scientists have reported a variety of chemical and physical methods for production of MNPs, for instance, chemical reduction [ 31 ], microemulsion [ 32 , 33 ], thermal decomposition [ 34 , 35 ], sonochemical [ 36 , 37 ], polyol method [ 38 , 39 ], microwave-assisted method [ 40 , 41 ], laser ablation [ 42 ], sputtering deposition [ 43 ], lithography [ 44 ], pulsed electrochemical etching [ 45 ], vapor deposition [ 46 ] and sol–gel [ 47 ] (Fig. 2 ).…”

Synthesis of Supported Mesoporous Catalysts Using Supercritical CO2

“…FSCs are also utilized in hydrothermal or solvothermal synthesis, participating through chemical reactions, such as hydrolysis and dehydration of solutions of metal salts in subcritical or supercritical water [30][31][32] or another solvent [33][34][35]. A novel recently synthesis technique is FSC microemulsion, in which water droplets in sc-CO 2 function as a micro-reactor [36][37][38][39].…”