Tin sulfides, 474

The synthesis and characterization of narrow-bandgap semiconductors, especially SnS2 and SnS, have received much attention in the last few years, due to their optical and electronic properties. xin sulfides comprise an interesting class of semiconductor materials. A variety of phases are known, such as SnS (herzenbergite), SnS2 (berndtite - 70 polytypes known), Sni+ Sn (non-stoichiometric), 

Sn2S3 (ottemannite, three polytypes), Sn4S5, and a number of alkaline and alkaline earth tin-based polysulfides.55 

A number of synthetic approaches have been proposed in order to prepare nanosized grains of tin(II) and tin(IV) chalcogenides. Thermal decomposition of (PhCH2)2SnX 3, (X = Se and Te) in an inert atmosphere has been used to prepare SnSe, SnTe, and Sn(Sei j Sj ).2 0  

Tin(II) sulfide semiconductor nanometric particles have been prepared by the thermal decomposition at 350 °C in air of R4Sn4Se (R = Me, n-Bu and Ph). Further heating to 500 °C in an N2 atmosphere led to the pure orthorhombic Sn2S3.  

In contrast to Sn-based oxide Alms, widely prepared by CVD techniques, this methodology has been 

Mishra et al. [198] discussed in an exemplary way the dark and photocorrosion behavior of their SnS-electrodeposited polycrystalline films on the basis of Pourbaix diagrams, by performing photoelectrochemical studies in aqueous electrolytes with various redox couples. Polarization curves for the SnS samples in a Fe(CN) redox electrolyte revealed partial rectification for cathodic current flow in the dark, establishing the SnS as p-type. The incomplete rectification was 

---

Tin Sol process Tin sphene Tinstone Tin sulfide Tinted contact lenses Tinted sealers Tin tetrachloride... 

If tin and sulfur are heated, a vigorous reaction takes place with the formation of tin sulfides. At 100—400°C, hydrogen sulfide reacts with tin, forming stannous sulfide however, at ordinary temperatures no reaction occurs. Stannous sulfide also forms from the reaction of tin with an aqueous solution of sulfur dioxide. Molten tin reacts with phosphoms, forming a phosphide. Aqueous solutions of the hydroxides and carbonates of sodium and potassium, especially when warm, attack tin. Stannates are produced by the action of strong sodium hydroxide and potassium hydroxide solutions on tin. Oxidizing agents, eg, sodium or potassium nitrate or nitrite, are used to prevent the formation of stannites and to promote the reactions. 

Schwefel-weinsaure, /. sulphovinic acid (old name for ethylsulfuric add). -werk, n. sulfur refinery, -wismut, n. bismuth sulfide, -wurz, /. brimstonewort. -wurzel, /. (Pharm.) peucedanum root, brimstonewort root, -zink, m. n. zinc sulfide, -zinkweiss, n. a pigment containing chiefiy zinc sulfide (litho-pone, zincolith). -zinn, n. tin sulfide. 

Zion-saum, m. list of tin, selvedge, -allure, /. stannic acid, -saureonhydrid, n. stannic anhydride, tin dioxide, -schlich, m. (Ores) tin slimes, fine tin. -schrei, m. = 2Unngeschrei. -seife, /. (Mining) stream tin. -soda, /. sodium stannate. -staub, m. tin dust, -stein, m. tinstone, cassiterite. -sulfid, n. tin sulfide, specif, stannic sulfide, tin(IV) sulfide. -BuUocyanid, 1. tin thiocyanate, specif. 

The preparation of some polychalcogenide solids can be achieved at 200-450 °C by molten salt (flux) methods. The reaction of tin with alkali metal sulfides in the presence of Ss at 200-450 °C gives a variety of alkali metal tin sulfides depending on the ratio of the starting materials, the reaction temperature, and the alkah metals (Scheme 30) [90]. These alkali metal tin sul-... 

Fig. 5.2 The n-Cd(Se,Te)/aqueous Cs2Sx/SnS solar cell. P, S, and L indicate the direction of electron flow through the photoelectrode, tin electrode, and external load, respectively (a) in an illuminated cell and (b) in the dark. For electrolytes, m represents molal. Electron transfer is driven both through an external load and also into electrochemical storage by reduction of SnS to metaUic tin. In the dark, the potential drop below that of tin sulfide reduction induces spontaneous oxidation of tin and electron flow through the external load. Independent of illumination conditions, electrons are driven through the load in the same direction, ensuring continuous power output. (Reproduced with permission from Macmillan Publishers Ltd [Nature] [60], Copyright 2009)...

Stannite is the most common tin sulfide mineral in the ore deposits associated with tin mineralization. This mineral sometimes contains appreciable amounts of zinc, together with iron. Several workers have suggested that the zinc and iron contents of stannite are related to temperature. With respect to the study of the phase relationships in the pseudobinary stannite-kesterite system. Springer (1972) proposed zincic stannite as a possible geothermometer mainly based on the chemical compositions of the two exsolved phases (stannite and kesterite). Nekrasov et al. (1979) and Nakamura and Shima (1982) experimentally determined the temperature dependency of iron and zinc partitioning between stannite and sphalerite. 

Shimizu and Shikazono (1987) studied the compositional relations of coexisting stannoidite, sphalerite and tennantite-tetrahedrite (Fig. 1.182). Based on these data they estimated the sulfur fugacity of stannoidite-bearing tin ore. Considering the complementary work on stannite-bearing tin ores from Japanese ore deposits (Shimizu and Shikazono, 1985), a comparison between environmental conditions of these two types of tin sulfides was made. Their study is described below. 

As mentioned already, Shimizu and Shikazono (1985) have estimated the /s2 temperature range for stannite-bearing assemblages from Japanese vein-type and skam-type tin deposits. This estimated /sj-temperature region is also shown in Fig. 1.183. The /s2-temperature range for the formation of these two types of tin sulfides is different. 

Since the first synthesis of mesoporous materials MCM-41 at Mobile Coporation,1 most work carried out in this area has focused on the preparation, characterization and applications of silica-based compounds. Recently, the synthesis of metal oxide-based mesostructured materials has attracted research attention due to their catalytic, electric, magnetic and optical properties.2 5 Although metal sulfides have found widespread applications as semiconductors, electro-optical materials and catalysts, to just name a few, only a few attempts have been reported on the synthesis of metal sulfide-based mesostructured materials. Thus far, mesostructured tin sulfides have proven to be most synthetically accessible in aqueous solution at ambient temperatures.6-7 Physical property studies showed that such materials may have potential to be used as semiconducting liquid crystals in electro-optical displays and chemical sensing applications. In addition, mesostructured thiogermanates8-10 and zinc sulfide with textured mesoporosity after surfactant removal11 have been prepared under hydrothermal conditions. 

The heat sensitivity (above) may explain the explosions which occur on contact of many readily oxidisable materials with this powerful oxidant. Such materials include ammonia, potassium arsenic, antimony sulfur, charcoal (adsorptive heating may also contribute) calcium phosphide, phosphine, phosphorus hydrogen sulfide, antimony sulfide, barium sulfide, mercury sulfide and tin sulfide [1], Various organic materials (paper, cork, rubber, turpentine, etc.) behave similarly [2]. Mixtures with hydrogen detonate on ignition [1]. 

The reaction of Ph3SnNa with (Bu2SnS)3 gave the symmetric tin sulfide (Ph3Sn)2S (equation 154)41. 

Layered tin sulfide mesostructures were synthesized using a cationic surfactant as template, and tin chloride and sodium sulfide as sources of tin and sulfide [36], The structure was composed of Sn2S64 dimers charge-balanced by dodecylammonium cations. A mesostructured tin sulfide mesh phase was synthesized by reacting SnCl4, (NH4)2S and hexadecylamine (HDA) under aqueous basic conditions at 150°C [37], The structure was found to be... 

Tin sulfide in marine sediments can react with CH3I—a ubiquitous biogenic molecule in sea water—to give tin methyls ... 

The presence of early transition metals or rare earth elements is not necessary for the stabilization of metal-rich compounds. This is shown by the metal-rich nickel-tin sulfides Ni6SnS2 and Ni9Sn2S2, which were found during investigations of phase relations in the ternary Ni-Sn-S... 

---