Solvent-Less Solid State Synthesis of Dispersible Metal and Semiconducting Metal Sulfide Nanocrystals

Abstract

Monolayer protected metal and metal sulfide nanocrystals (NCs) have mainly two constituents; the inorganic metal or metal chalcogenide complex as core and organic molecule as shell. Noticing that metal thiolates have these ingredients inbuilt in their structure, we investigated them as possible precursors for the preparation of monolayer protected metal and metal sulfide NCs via solid state grinding method. Accordingly silver and gold NCs have been prepared using a solvent less green approach, by the simple and convenient solid state grinding of the corresponding metal thiolate with sodium borohydride. Similarly, a large variety of uniform-sized semiconducting NCs of metal sulfides including PbS, CdS, ZnS, MnS, Ag2S, and CuS could also be synthesized by the same solid state route by grinding the metal thiolates with octyl dithiocarbamic acid (C8DTCA) and in some cases C8DTCA plus small amount of oleylamine as sulfur source. Interestingly, this simple technique could be used to prepare sub-3 nm NCs like Ag2S, PbS, and CuS which are otherwise difficult to prepare by the conventional high temperature solution routes also. Most gratifyingly, all these NCs, though were prepared by a solvent less grinding method, could be easily dispersed in nonpolar solvents as the preparation method ensued the formation of organic molecule capped NCs.

Near- to Long-Wave-Infrared Mercury Chalcogenide Nanocrystals from Liquid Mercury

“…A second key advantage of this approach based on liquid mercury is the possibility of conducting highly concentrated syntheses leading to several grams of NCs per experiment . A significant effort has been conducted to achieve gram-scale synthesis for PbS, ,− but this effort was still lacking for HgTe, which has been identified as a major limitation toward industrial transfer of mid-IR NCs . Here, we have been able to develop a procedure which allows the synthesis of 7 g of HgTe NCs out of 100 mL of reaction medium and which used only 50 mL of solvent for two steps of cleaning (see Figures a,b and S15).…”

Challenges and opportunities in the bottom-up mechanochemical synthesis of noble metal nanoparticles

“…105 More recently, monodispersed Ag NPs (4.04 AE 0.45 nm) were synthesized using a silver thiolate as a starting material. 99 By manually grinding the metal precursor with NaBH 4 in an agate mortar, the metal thiolates precursor were reduced to generate Ag and thiol stabilizing agents. The thiol molecules are responsible to control the particle growth and to stabilize the Ag NPs.…”

“…This was mainly used for the preparation of semiconducting PbS, CdS, ZnS, and CuS NPs from Pb, Cd, Zn, and Cu thiolates, respectively. 99 Other thiolates have been used in the synthesis of Ag clusters by simple manual grinding. 107,108,120 The synthetic procedure afforded Ag 9 , 120 Ag 32 (ref.…”

One-Pot Phosphine-Free Route for Single-Component White Light Emitting CdSexSy Alloy Nanocrystals

“…CdS and CdSe-based nanocrystals have been explored extensively for cellular imaging/labeling, , solar cell, , and light emitting devices. − The unique optoelectronic properties in these nanocrystals often arise due to the confinement of charge carriers . Further, tunable emission in colloidal nanocrystals is significantly influenced by the composition of the constituents. − The high extinction coefficient and photoluminescence quantum yield (PLQY) are added advantages of semiconductor nanocrystals . However, the use of the toxic phosphine-based solvent and often tedious fabrication routes retard the wide-scale application.…”

“…16−18 The high extinction coefficient and photoluminescence quantum yield (PLQY) are added advantages of semiconductor nanocrystals. 19 However, the use of the toxic phosphine-based solvent and often tedious fabrication routes retard the wide-scale application. Hence, it is worthy of developing cost-effective and environmentally benign synthetic protocols for semiconductor nanocrystals for solid-state white light emission.…”