Sn Sulfide Research Articles

Constructing novel Sn-Mo bimetallic sulfide heterostructures for enhanced catalytic performance towards the hydrogen evolution reaction

Understanding the design principles of efficient electrocatalysts using the structure–activity relationship is crucial for the advancement of energy-related applications, and specifically the hydrogen evolution reaction (HER). Non-precious electrocatalysts with low overpotentials are essential for driving the HER and achieving high energy efficiency. In this study, we synthesized and thoroughly investigated various heterostructures combining Mo and Sn sulfides, ranging from complete phase-separated hybrids to homogeneous mixtures: SnS@MoS2 core–shell structures, SnS/MoS2 with edge-rich Mo and (SnxMo1-x)S with uniformly distributed Sn-Mo. Our findings reveal that the SnS@MoS2 structure exhibited relatively high intrinsic activity characterized by a high electrochemical active surface area and rapid charge transfer kinetics, thereby enhancing the HER catalytic performance. The presence of fluffy MoS2 layers provided an abundance of optimized sites for HER, potentially due to strain and defects such as S vacancies, known as active catalytic sites. The optimal structure facilitated efficient charge transfer from the core to the shell, improving conductivity and catalytic activity. Our research highlights the advantages of a core–shell hybrid structure, offering guiding principles for the development of an optimal SnS@MoS2 catalyst.

Enhanced activation of H2O2 by bimetallic Cu2SnS3: A new insight for Cu (II)/Cu (I) redox cycle promotion

HypothesisDespite that the development of Cu2SnS3 (CTS) catalyst has attracted increasing interests, few study has reported to investigate its heterogeneous catalytic degradation of organic pollutants in a Fenton-like process. Furthermore, the influence of Sn components towards Cu (II)/Cu (I) redox cycling in CTS catalytic systems remains a fascinating research. ExperimentsIn this work, a series of CTS catalysts with controlled crystalline phases were prepared via a microwave-assisted pathway and applied in the H2O2 activation for phenol degradation. The efficiency of phenol degradation in CTS-1/H2O2 system (CTS-1: the molar ratio of Sn (copper acetate) and Cu (tin dichloride) is determined to be Sn:Cu = 1:1) was systematically investigated by controlling various reaction parameters including H2O2 dosage, initial pH and reaction temperature. We discovered that Cu2SnS3 exhibited superior catalytic activity to the contrast monometallic Cu or Sn sulfides and Cu (I) acted as the dominant active sites. The higher Cu (I) proportions conduce to the higher catalytic activities of CTS catalysts. Quenching experiments and electron paramagnetic resonance (EPR) further proved that the activation of H2O2 by CTS catalyst produces reactive oxygen species (ROS) and subsequently leads to degradation of the contaminants. A reasonable mechanism of enhanced H2O2 activation in Fenton-like reaction of CTS/H2O2 system was proposed for phenol degradation by investigating the roles of copper, tin and sulfur species. FindingsThe developed CTS acted as a promising catalyst in Fenton-like oxidation progress for phenol degradation. Importantly, the copper and tin species contribute to a synergetic effect for the promotion of Cu (II)/Cu (I) redox cycle, which thus enhanced the activation of H2O2. Our work may offer new insight on the facilitation of Cu (II)/Cu (I) redox cycle in Cu-based Fenton-like catalytic systems.

Weathering of stannite–kësterite [Cu2(Fe,Zn)SnS4] and the environmental mobility of the released elements

Abstract. The sulfidic waste dumps of the historical mining sites Giftkies and Kaňk (Czech Republic) have been exposed to a temperate climate over decades. This exposure generated low-pH conditions caused by metal sulfide decomposition. Tin sulfides of the stannite–kësterite series [Cu2(Fe,Zn)SnS4] are common Sn minerals in the ores at the investigated sites. They decompose under acidic and oxidizing conditions and form in situ secondary precipitates. Compositional analyses of primary and secondary minerals were collected by electron microprobe to track the environmental mobility of the released elements during weathering. Transmission electron microscopy revealed a diffusion-driven alteration of stannite to Sn-rich chalcopyrite and the precipitation of native copper and silver from stannite. In assemblages containing arsenopyrite, an in situ and amorphous Sn–Fe–As (SFA)-rich phase precipitated close to the Sn sulfide. The SFA precipitate contains very little sulfur, which was probably released to the aqueous phase as oxidized species, whereas small amounts of Cu and Zn were captured by the SFA. This precipitate is metastable and acts as a temporaneous sink for mobile elements (Cu, Zn) and elements derived from acid-soluble silicates and phosphates (Ca, Si, Al, and P). With advanced weathering, complex redox reactions result in the precipitation of magnetite as an oxidation product of the sulfidic material under oxidative conditions. The stable minerals goethite and cassiterite mark the end of the weathering sequence and crystallized from the amorphous SFA precipitate.

Tin-Based Anode Materials for Stable Sodium Storage: Progress and Perspective.

Because of concerns regarding shortages of lithium resources and the urgent need to develop low-cost and high-efficiency energy-storage systems, research and applications of sodium-ion batteries (SIBs) have re-emerged in recent years. Herein, recent advances in high-capacity Sn-based anode materials for stable SIBs are highlighted, including tin (Sn) alloys, Sn oxides, Sn sulfides, Sn selenides, Sn phosphides, and their composites. The reaction mechanisms between Sn-based materials and sodium are clarified. Multiphase and multiscale structural optimizations of Sn-based materials to achieve good sodium-storage performance are emphasized. Full-cell designs using Sn-based materials as anodes and further development of Sn-based materials are discussed from a commercialization perspective. Insights into the preparation of future high-performance Sn-based anode materials and the construction of sodium-ion full batteries with a high energy density and long service life are provided.

Mineralogical Features of Ore Diagenites in the Urals Massive Sulfide Deposits, Russia

In weakly metamorphosed massive sulfide deposits of the Urals (Dergamysh, Yubileynoe, Yaman-Kasy, Molodezhnoe, Valentorskoe, Aleksandrinskoe, Saf’yanovskoe), banded sulfides (ore diagenites) are recognized as the products of seafloor supergene alteration (halmyrolysis) of fine-clastic sulfide sediments and further diagenesis leading to the formation of authigenic mineralization. The ore diagenites are subdivided into pyrrhotite-, chalcopyrite-, bornite-, sphalerite-, barite- and hematite-rich types. The relative contents of sphalerite-, bornite- and barite-rich facies increases in the progression from ultramafic (=Atlantic) to bimodal mafic (=Uralian) and bimodal felsic (=Baymak and Rudny Altay) types of massive sulfide deposits. The ore diagenites have lost primary features within the ore clasts and dominantly exhibit replacement and neo-formed nodular microtextures. The evolution of the mineralogy is dependent on the original primary composition, sizes and proportions of the hydrothermal ore clasts mixed with lithic serpentinite and hyaloclastic volcanic fragments together with carbonaceous and calcareous fragments. Each type of ore diagenite is characterized by specific rare mineral assemblages: Cu–Co–Ni sulfides are common in pyrrhotite-rich diagenites; tellurides and selenides in chalcopyrite-rich diagenites; minerals of the germanite group and Cu–Ag and Cu–Sn sulfides in bornite-rich diagenites; abundant galena and sulfosalts in barite- and sphalerite-rich diagenites and diverse tellurides characterize hematite-rich diagenites. Native gold in variable amounts is typical of all types of diagenites.

Controlling the formation of self-assembled Cu–Sn sulfide with a hoya-like structure for its electrochemical performance

Self-assembled hoya-like micron-spheres (Cu–Sn–S) with honeycomb pores were fabricated via a facile gelation–solvothermal–annealing three-step method and exhibited enhanced electrochemical performance for supercapacitors and HER.

Luminescence of defects in the structural transformation of layered tin dichalcogenides

Layered tin sulfide semiconductors are both of fundamental interest and attractive for energy conversion applications. Sn sulfides crystallize in several stable bulk phases with different Sn:S ratios (SnS2, Sn2S3, and SnS), which can transform into phases with a lower sulfur concentration by introduction of sulfur vacancies (VS). How this complex behavior affects the optoelectronic properties remains largely unknown but is of key importance for understanding light-matter interactions in this family of layered materials. Here, we use the capability to induce VS and drive a transformation between few-layer SnS2 and SnS by electron beam irradiation, combined with in-situ cathodoluminescence spectroscopy and ab-initio calculations to probe the role of defects in the luminescence of these materials. In addition to the characteristic band-edge emission of the endpoint structures, our results show emerging luminescence features accompanying the SnS2 to SnS transformation. Comparison with calculations indicates that the most prominent emission in SnS2 with sulfur vacancies is not due to luminescence from a defect level but involves recombination of excitons bound to neutral VS in SnS2. These findings provide insight into the intrinsic and defect-related optoelectronic properties of Sn chalcogenide semiconductors.

In-bearing potential of tin‒sulfide mineralization in ore deposits of the Russian Far East

The increased demand for indium has made it necessary to revise prospects of In-bearing tin ore deposits in the Russian Far East on the basis of geological data and results of recent analytical methods (X-ray fluorescence with synchrotron radiation, atomic absorption, and ICP-MS). The average In contents in ores of the Tigrinoe and Pravourmiiskoe deposits vary from 55 to 70 ppm, which allows tin ore deposits with Sn‒sulfide mineralization to be considered as quite promising with respect to In production from ores of Russian deposits. By their estimated In reserves, the Tigrinoe and Pravourmiiskoe deposits may be attributed to large ore objects.

Indium in cassiterite and ores of tin deposits

The results obtained with LA-ICP-MS by less abundant lighter 113In isotope and EPMA show that in cassiterite of cassiterite–quartz veins the indium contents do not exceed 160ppm, while cassiterite from Sn–sulfide veins is characterized by higher indium contents from 40 to 485ppm; sulfides of Sn–sulfide veins unlike sulfides of cassiterite–quartz veins also have the highest indium contents: Fe-sphalerite (100–25,000ppm), chalcopyrite (up to 1000ppm), and stannite (up to 60,000ppm). Indium contents in the Sn–sulfide ore of the Tigrinoe and Pravourmiiskoe deposits obtained using SR-XRF, ICP-MS and atomic absorption methods range from 10 to 433ppm with average values of 56–65ppm. Indium-rich Sn–sulfide mineralization in five large Sn–Ag ore districts of the Far East Russia (Khingansky, Badzhalsky, Komsomolsky, Arminsky, Kavalerovsky) provides the impetus for further exploration of deposits with Sn–sulfide mineralization as the most promising indium resources in Russia. Empirical observations from geology and geochronology of cassiterite–quartz and Sn–sulfide mineralization show that the combined contribution from granite and alkaline–subalkaline mafic sources and multistage ore-forming processes doubled indium resources of deposits being the main factors in the formation of high grade indium mineralization.

Real-time investigations on the formation reactions during annealing of sulfurized Cu–Sn precursors

The quaternary compound kesterite Cu 2ZnSnS 4 (CZTS) is a promising candidate for the production of low-cost thin film solar cells. Depending on the precursor composition and deposition technique several intermetallic precursor phases may appear, affecting the formation reactions during the crystallization process of the thin film absorber. A better understanding of these formation reactions in the system Cu–Zn–Sn–S is required for the optimization of CZTS absorbers and future development of solar modules. The crystallization of CZTS is completed by the reaction of Cu 2SnS 3 and ZnS. The formation of Cu 2SnS 3 itself depends on the different available precursor compounds after sulfur evaporation. Incomplete conversion of binary sulfides during annealing may lead to the formation of undesirable compounds, i.e. the transformation of Cu 2SnS 3 into Cu 4SnS 4 via reaction with Cu 2- x S, which affect or even inhibit the crystallization of CZTS. Therefore a precise knowledge about formation reactions of binary and ternary Cu–Sn sulfides during annealing at low temperatures is important to crystallize a monophase CZTS absorber. Real-time investigations on the formation reactions in the quaternary and also the ternary subsystems of Cu–Zn–Sn–S while annealing stacked elemental layers elucidate the reaction paths of binary and ternary sulfides. We report on results of time-resolved and angle-dispersive XRD experiments during annealing comparing the formation reactions in sulfurized Cu–Sn precursors prepared by different deposition techniques.

Metal-residence sites in lavas and tuffs from Volc�n Popocat�petl, Mexico: implications for metal mobility in the environment

Volcan Popocatepetl is a Quaternary stratovolcano located 60 km southeast of Mexico City. The summit crater is the site of recent ash eruptions, excess degassing, and dacite dome growth. The modern cone comprises mainly pyroclastic flow deposits, airfall tephras, debris flows, and reworked deposits of andesitic composition; it is flanked by more mafic monogenetic vents. In least-degassed fallout tuffs and mafic scoria, transition metals are concentrated in phases formed before eruption, during eruption, and after eruption. Preeruptive minerals occur in both lavas and tephra, and include oxides and sulfides in glass and phenocrysts. The magmatic oxides consist of magnetite, ilmenite, and chromite; the sulfides consist of both (Fe,Ni)1-xS (MSS) and Cu–Fe sulfide (ISS). Syn- and posteruptive phases occur in vesicles in both lavas and tephra, and on surfaces of ash and along fractures. The mineral assemblages in lavas include Cu–Fe sulfide and Fe–Ti oxide in vesicles, and Fe sulfide and Cu–Fe sulfide in segregation vesicles. Assemblages in vesicles in scoria include Fe–Ti oxide and rare Fe–Cu–Sn sulfide. Vesicle fillings of Fe–Ti oxide, Ni-rich chromite, Fe sulfide, Cu sulfide, and barite are common to two pumice samples. The most coarse-grained of the vesicle fillings are Cu–Fe sulfide and Cu sulfide, which are as large as 50 μ in diameter. The youngest Plinian pumice also contains Zn(Fe) sulfide, as well as rare Ag–Cu sulfide, Ag–Fe sulfide, Ag bromide, Ag chloride, and Au–Cu telluride. The assemblage is similar to those typically observed in high-sulfidation epithermal mineralization. The fine-grained nature and abundance of syn- and/or posteruptive phases in porous rocks makes metals susceptible to mobilization by percolating fluids. The abundance of metal compounds in vesicles indicates that volatile exsolution prior to and/or during eruption played an important role in releasing metals to the atmosphere.

On the occurrence and role of SnO2, SnS and FeSn2 in coal hydroliquefaction experiments using tin-based catalysts

Mossbauer Spectroscopy, X-Ray Diffraction and Electron Microscopy were applied to the study of solid residues of coal hydroliquefaction, for which tin-based catalysts were used. In the general case hydroliquefaction runs were performed in the presence of added sulphur and of finely dispersed SnO2 as a catalyst precursor. The only observed tin species were SnO2 and SnS, the former with percentages higher than expected from XRD, due to its large f factor, the latter as a symmetric doublet, which suggests that any asymmetry should be ascribed to small particle sizes rather than to structure. When the S content was only that of coal and the catalyst precursor β-Sn, FeSn2 occurred together with Sn sulfides and oxides, while no β-Sn was detected. The main catalytic role is ascribed to SnS.

Phase relationships in the systems MoSnS, WSnS and MoWS

By using the evacuated and sealed capsule technique, phase relationships in the systems Mo-Sn-S, W-Sn-S and Mo-W-S were studied in the temperature range 500–800 °C. One ternary compound, SnMo 5S 6 and two liquids, L 1 (Sn) and L 2 (Sn sulfide), are stable in the system Mo-Sn-S at 800 °C and form equilibrium assemblages with MoS 2, Mo 2S 3, SnS 2, SnS and Mo. No solid solution was found between the two layer-type disulfides. In the system W-Sn-S, WS 2 forms equilibrium assemblages with SnS 2, SnS, L 1 and L 2 at 800 °C; at 500 °C the assemblage of W + SnS becomes a stable one. The system Mo-W-S is characterized by two solid solution series, (W, Mo) and (W, Mo)S 2, in the temperature range 500–800 °C.