Bismuth Sulfides Research Articles

Solvent Selection as a Key Factor in the Performance of Semitransparent Heterojunctions Composed of Hydrogenated Nanotubes and Bismuth Sulfides.

Research on titanium nanotubes modified with metal sulfides, particularly bismuth sulfide (Bi2S3), aims to create heterostructures that efficiently absorb sunlight and then separate photogenerated charge carriers, thereby enhancing the energy conversion efficiency. This study shows a key role of solvent used for sulfide and bismuth salt solutions used during successive ionic layer adsorption and reaction (SILAR) onto the morphology, structure, and photoresponse of the heterojunction where one element is represented by semitransparent titania nanotubes (gTiNT) and the second is Bi2S3. Using 2-methoxyethanol and methanol during SILAR, results in remarkably photoactive 3D heterostructure and recorded photocurrents were 44 times higher compared to bare titania nanotubes. Additionally, methanol- and 2-methoxyethanol-based processing allowed uniform deposition of the sulfide, which was not reached for other solvents. XPS studies not only confirm formation of bismuth sulfides but also indicate that BixTiyOz compound can arise that can affect both stability and photoactivity of the electrode material.

Ultralow Lattice Thermal Conductivity and High ZT Beyond 1 Realized in Bi2S3 Nanocomposites via Bottom-Up Structure Design.

Bismuth sulfides (Bi2S3), an n-type thermoelectric material, in expensive, and environmentally friendly. However, it has poor electrical conductivity due to its low electron concentration, and its thermoelectric properties need improvement. By adjusting the properties of microstructural units and then designing and preparing bulk materials, the transport properties are modulated to optimize thermoelectric properties. The textured structure and metal Bi dispersed in grain boundaries improved the carrier mobility, the Cl dopingimproved carrier concentration. The textured structure and metalBi dispersed in grain boundaries improved the carrier mobility, the Cl dopingimproved carrier concentration. The Bi2S3-Cl samples reduce using N2H4·H2O for 5 min at 673 K have a peak power factor (PF) reaching 676.6 µWm-1K-2, more than 6 times that of pristine Bi2S3. Furthermore, the point defects, dislocations, and the micropores caused by a part of Bivolatilization contribute to the strong phonon scattering, resulting in a low lattice thermal conductivity of 0.28 Wm-1K-1 at 623K. Due to the synergistically optimized electrical and thermal transport properties, the values of the maximum thermoelectric figure of merit (ZTmax) and the average thermoelectric figure of merit (ZTave) for the Bi2S3-Cl samples reduce using N2H4·H2O for 5 min are 1.01 at ≈673 K and 0.63 (323-673 K), respectively. This study demonstrates that bottom-up structure design can effectively strategize the improvement of thermoelectric performance.

Selenide-doped bismuth sulfides (Bi2S3-xSex) and their hierarchical heterostructure with ReS2 for sodium/potassium-ion batteries

In this work, selenide-doped bismuth sulfides (Bi2S3-xSex) was successfully prepared through Se doping Bi2S3 Se to improve the electronic conductivity and increase the interlayer spacing. Then the anisotropic ReS2 nanosheet arrays were grown on the surface of Bi2S3-xSex to form a hierarchical heterostructure (Bi2S3-xSex@ReS2). The doping and construction of heterostructure processes can greatly improve the electrochemical conductivity of electrode materials and relieve the volume expansion during the continuous charge/discharge processes. While applied as SIBs anode, the specific capacity of 330 mAh g−1 was maintained after 450 cycles at the current density of 1.0 A g−1. It can also keep 200 mAh g−1 specific capacity after 900 cycles at 1.0 A g−1 for the anode of PIBs. This heterogeneous engineering and doping dual strategies could provide a good idea for the synthesis of new bimetallic sulfides with outstanding battery performance for SIBs and PIBs.

A review of bismuth-based photocatalysts for antibiotic degradation: Insight into the photocatalytic degradation performance, pathways and relevant mechanisms

The intensive production and utilization of antibiotics worldwide has inevitably led to releases of very large amounts of these medicines into the environment, and numerous strategies have recently been developed to eliminate antibiotic pollution. Therefore, bismuth-based photocatalysts have attracted much attention due to their high adsorption of visible light and low production cost. This review summarizes the performance, degradation pathways and relevant mechanisms of typical antibiotics during bismuth-based photocatalytic degradation. First, the band gap and redox ability of the bismuth-based catalysts and modified materials (such as morphology, structure mediation, heterojunction construction and element doping) were compared and evaluated. Second, the performance and potential mechanisms of bismuth oxides, bismuth sulfides, bismuth oxyhalides and bismuth-based metal oxides for antibiotic removal were investigated. Third, we analysed the effect of co-existing interfering substances in a real water matrix on the photocatalytic ability, as well as the coupling processes for degradation enhancement. In the last section, current difficulties and future perspectives on photocatalytic degradation for antibiotic elimination by bismuth-based catalysts are summarized. Generally, modified bismuth-based compounds showed better performance than single-component photocatalysts during photocatalytic degradation for most antibiotics, in which h+ played a predominant role among all the related reactive oxygen species. Moreover, the crystal structures and morphologies of bismuth-based catalysts seriously affected their practical efficiencies.

Depression behavior and mechanism of pyrogallol on bismuthinite flotation

Pyrogallol, an eco-friendly derivative of tannic, was a potential substitute of toxic depressant used in bismuth-molybdenum (Bi–Mo) sulfide ore flotation. However, unclear depression mechanisms of pyrogallol on bismuth sulfides hindered its further application in the industry. In this work, the effect of pyrogallol on the flotation performance of bismuthinite was evaluated using flotation tests, and associated interaction mechanisms were investigated by using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations. Micro-flotation tests showed that pyrogallol exhibited excellent depressing performance to bismuthinite in the whole pH range tested (2–12). In the presence of 300 g/t pyrogallol, over 95% of bismuthinite was effectively depressed in the real flotation process at pH around 9. FTIR and XPS results demonstrated that pyrogallol was chemisorbed on bismuthinite through the interactions among Bi atoms exposed on the bismuthinite surface and O−H groups in pyrogallol. The adsorption mechanism was further ascertained by DFT calculations, which revealed that the Bi–O–C single bond and the five-membered ring complex models were involved in the chemisorption of pyrogallol on bismuthinite surface. The work presented here not only provides new insights into the inhibition mechanisms of pyrogallol on bismuthinite but also provides theoretical support for the industrial application of pyrogallol.

Tailoring the morphology, crystalline structure, and electrochemical properties of nanostructured Bi2S3 using various solvent mixtures

Among novel nanostructured materials, transition metal chalcogenides (i.e., sulfides and selenides) emerged as promising candidates due to their unique electrochemical properties. The following study presents a facile synthesis approach of Bi2S3 nanostructures using solvent mixtures of ethanol and water with different volume ratios and ammonium sulfide as a sulfur precursor. The resultant bismuth sulfides were characterized by field-emission scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and nitrogen sorption at 77 K. The adjustment of the solvent mixture revealed the possibility of customizing the crystalline structure from amorphous to fully crystalline, as well as the morphology of the Bi2S3, which subsequently influenced on their electrochemical properties. Bi2S3 synthesized in a solvent mixture of ethanol-to-water volume ratio 1:2 (Bi2S3-EW12) exhibited almost fully crystalline structure and nanoplatelet-like morphology, which translated to the best electrochemical performance. Bi2S3-EW12 achieved specific capacity of 748 C g−1 in an aqueous 6 mol L−1 KOH electrolyte and maintained the highest capacity value at a large current density of 20 A g−1.

Scalable one-pot synthesis of bismuth sulfide nanorods as an electrode active material for energy storage applications

The quest for developing the scalable methods of synthesis of materials with potential electrochemical energy storage applications remains a great challenge. Herein, we propose a facile, one-step chemical precipitation method for the synthesis of Bi2S3 with the nanorods morphology. Influence of different synthesis temperatures on the physical, chemical, and electrochemical performance was investigated. Relatively low BET surface area and mesopore volume of Bi2S3 increased with the higher reaction temperature. Bismuth sulfides synthesized at various temperatures were used as an electrode active material in supercapacitor. The semiconductive properties of Bi2S3 resulted in exceptional capacitive behavior. Bismuth sulfide synthesized at 75 °C exhibited a specific capacitance of 457 F g−1 at 1 A g−1 in 6 mol L−1 KOH solution as an electrolyte. Moreover, material prepared at 75 °C maintained the best capacitance value at a large current density of 20 A g−1, compared with bismuth sulfides synthesized at the temperatures of 0 °C and 25 °C.

Sandwich-like graphene-Bi2S3 hybrid derived from (BiO)2CO3 nanosheets as advanced anode materials for lithium/sodium ion batteries

Bismuth sulfides (Bi2S3) are potential electrode materials that have a high theoretical capacity for both lithium and sodium ion batteries. To better utilize the material in practical applications, it is urgent to solve the problem of severe capacity decay caused by low electronic conductivity and large volume change during cycling. Introducing graphene into the system would effectively alleviate these issues on account of the good electrical conductivity, high mechanical flexibility, and large surface area possessed by graphene. However, it is difficult to wrap Bi2S3 with a graphene layer due to the intrinsic hydrophobicity of graphene layers and the strong π-interaction of graphene nanosheets. In this work, sandwich-like graphene-Bi2S3 hybrids (rGO@Bi2S3) are synthesized from two-dimensional (BiO)2CO3 nanosheets (BOC NSs) by electrostatic self-assembly and a subsequent sulfidation process with the assistance of a cationic surfactant. The electrostatic force provides an efficient approach for graphene layers to wrap well around BOC NSs to form a sandwich-like structure that can be retained after the sulfidation process. Benefitting from the merits of high electronic conductivity, robust structure stability, and sufficient space for volume expansion, the as-obtained rGO@Bi2S3 hybrids show both high capacity and cycle stability as the anode of lithium/sodium ion batteries.

Sulfur-Deficient Bismuth Sulfide/Nitrogen-Doped Carbon Nanofibers as Advanced Free-Standing Electrode for Asymmetric Supercapacitors.

The use of free-standing carbon-based hybrids plays a crucial role to help fulfil ever-increasing energy storage demands, but is greatly hindered by the limited number of active sites for fast charge adsorption/desorption processes. Herein, an efficient strategy is demonstrated for making defect-rich bismuth sulfides in combination with surface nitrogen-doped carbon nanofibers (dr-Bi2 S3 /S-NCNF) as flexible free-standing electrodes for asymmetric supercapacitors. The dr-Bi2 S3 /S-NCNF composite exhibits superior electrochemical performances with an enhanced specific capacitance of 466 F g-1 at a discharge current density of 1 A g-1 . The high performance of dr-Bi2 S3 /S-NCNF electrodes originates from its hierarchical structure of nitrogen-doped carbon nanofibers with well-anchored defect-rich bismuth sulfides nanostructures. As modeled by density functional theory calculation, the dr-Bi2 S3 /S-NCNF electrodes exhibit a reduced OH- adsorption energy of -3.15 eV, compared with that (-3.06 eV) of defect-free bismuth sulfides/surface nitrogen-doped carbon nanofiber (df-Bi2 S3 /S-NCNF). An asymmetric supercapacitor is further fabricated by utilizing dr-Bi2 S3 /S-NCNF hybrid as the negative electrode and S-NCNF as the positive electrode. This composite exhibits a high energy density of 22.2 Wh kg-1 at a power density of 677.3 W kg-1 . This work demonstrates a feasible strategy to construct advanced metal sulfide-based free-standing electrodes by incorporating defect-rich structures using surface engineering principles.

Magnetic and 151Eu Mössbauer spectroscopic studies on rare earth bismuth sulfides, EuLnBiS4 (Ln = Eu, Gd)

Ternary and quaternary rare earth bismuth sulfides EuLnBiS4 (Ln = Eu, Gd) have been investigated by X-ray diffraction, 151Eu Mössbauer spectroscopy, and magnetic susceptibility measurements. Both compounds have the orthorhombic CaFe2O4-type structure with space group Pnma. In Eu2BiS4, Eu2+ and Eu3+ ions occupy two crystallographically independent sites. The 151Eu Mössbauer spectra for Eu2BiS4 indicate that the Eu2+ and Eu3+ ions exist in the molar ratio of 1:1, and the Debye temperatures of Eu2+ and Eu3+ are 175 and 230 K, respectively. Magnetic susceptibility measurements for Eu2BiS4 and EuGdBiS4 reveal that an antiferromagnetic transition occurs at 2.8 and 6.5 K, respectively.

Exploring the PbS–Bi2S3 Series for Next Generation Energy Conversion Materials

As photovoltaics become an ever more important part of the global energy economy, the search for inexpensive, earth-abundant solar absorbers has grown rapidly. The binary compounds PbS and Bi2S3 have both seen success in previous photovoltaic studies; however, bulk PbS has a small band gap, restricting its efficiency, and Bi2S3, while strongly absorbing, can be limited by its layered structure. The mixed PbS–Bi2S3 series has previously been the focus of mostly structural studies, so in this article, we examine the electronic structure of the known members of this series using hybrid density functional theory. We find that the lead bismuth sulfides are able to retain optimal properties, such as low carrier effective masses and strong absorption, from both parent phases, with band gaps between 0.25 and 1.32 eV. PbBi2S4 emerges from our computational screening as a possible earth-abundant solar absorber, with a predicted maximum efficiency of 26% at a film thickness of 0.2 μm and with the retention of the th...

EXTREME PRESSURE SYNERGISTIC MECHANISM OF BISMUTH NAPHTHENATE AND SULFURIZED ISOBUTENE ADDITIVES

A four-ball tester was used to evaluate the tribological performances of bismuth naphthenate (BiNap), sulfurized isobutene (VSB), and their combinations. The results show that the antiwear properties of BiNap and VSB are not very visible, but they possess good extreme pressure (EP) properties, particularly sulfur containing bismuth additives. Synergistic EP properties of BiNap with various sulfur-containing additives were investigated. The results indicate that BiNap exhibits good EP synergism with sulfur-containing additives. The surface analytical tools, such as X-ray photoelectron spectrometer (XPS) scanning electron microscope (SEM) and energy dispersive X-ray (EDX), were used to investigate the topography, composition contents, and depth profile of some typical elements on the rubbing surface. Smooth topography of wear scar further confirms that the additive showed good EP capacities, and XPS and EDX analyzes indicate that tribochemical mixed protective films composed of bismuth, bismuth oxides, sulfides, and sulfates are formed on the rubbing surface, which improves the tribological properties of lubricants. In particular, a large number of bismuth atoms and bismuth sulfides play an important role in improving the EP properties of oils.

Poly(ionic liquid)-Mediated Morphogenesis of Bismuth Sulfide with a Tunable Band Gap and Enhanced Electrocatalytic Properties.

Conventional polymer additives have a substantial impact on synthetic inorganic chemistry, but critical shortcomings remain; for example, low solubility in organic solvents and potential thermodynamic aggregates. Poly(ionic liquid)s have now been used as efficient additives that enable a high level control of bismuth sulfide crystals with significant size and morphological diversities. The bismuth sulfides exhibit tunable band structure as a result of the quantum size effects. Moreover, poly(ionic liquid)s are able to couple with as-synthesized bismuth sulfides chemically and endow a modified surface electronic structure, which allows resultant products to possess outstanding electrocatalytic performance for water oxidation, although its commercial counterpart is catalytically inert.

LiBi3S5—A lithium bismuth sulfide with strong cation disorder

Among chalcogenide semiconductors for thermoelectric applications, alkali-metal bismuth compounds occur in many complex compositions favorable for high performance. Although LiBi3S5 had been announced in 1977, the potential 1D lithium-ion conductor has hitherto eluded selective synthesis and structure determination. In this study, we present a solid-state route to phase-pure LiBi3S5 powder starting from LiBiS2 and Bi2S3. Neutron diffractograms and lithium NMR spectra reveal its crystal structure to be a cation-disordered variety of the AgBi3S5 type (synthetic pavonite; monoclinic, C2/m). Topological analyses and lithium NMR relaxometry suggest that correlated lithium-ion diffusion with activation energies up to 0.66(2)eV occurs along the channels in b direction including tetrahedral voids. Because of cation disorder, immobile bismuth(III) ions clog these pathways, making LiBi3S5 a moderate to poor ionic conductor. The synthesis route reported is nonetheless promising for new lithium bismuth sulfides with, possibly ordered, structure types of the pavonite homologous series.

Electrochemical study of chalcopyrite dissolution in sulfuric, nitric and hydrochloric acid solutions

Electrochemical and surface analyses were carried out to study the leaching of chalcopyrite in acid media, aiming to increase copper extraction from low-grade chalcopyrite ores. Unpublished results include the use of electrochemical impedance spectroscopy (EIS) to characterize the dissolution resistance of chalcopyrite surfaces in 0.1mol·L−1 of hydrochloric, nitric or sulfuric acids. Potentiodynamic polarization, atomic absorption spectrometry and EIS analysis showed that hydrochloric acid solutions are more efficient leaching agents than nitric and sulfuric acids. The impedance results suggested that the chalcopyrite dissolution is a diffusion-controlled process in hydrochloric and sulfuric acids. The use of Raman spectroscopy and scanning electron microscopy with energy dispersive spectrometers (SEM/EDS) allowed the partial identification of lead and bismuth sulfides as impurities. Two products were identified on the surface of chalcopyrite after anodic polarization, i.e., sulfur in the sulfuric acid only and covellite in all three acids.

Development of principles of selection of reagents for flotation of antimony and bismuth minerals

3D models of clusters of antimony and bismuth sulfides were constructed. For these models, the charges of individual atoms and the electron populations of s-Pop, p-Pop, and d-Pop orbitals were determined. Collector activity evaluation prediction (CAEP) was made for a number of proposed reagents attached to atoms of clusters of minerals. CAEP characterizes the activity of a collector: the lower CAEP, the more preferable the interaction of the collector and the more efficient the flotation reagent. For flotation of antimony and bismuth minerals, a number of promising collectors were recommended.

مطالعات کانی سازی، ژئوشیمی، سیالات درگیر و ایزوتوپ پایدار گوگرد کانسار Cu-Zn-As باقرق با سنگ میزبان کربناته (شمال شرق انارک)

کانسار Cu-Zn-As باقرق در شمال شرق شهر انارک و در استان اصفهان قرار دارد. کانی‌سازی به‌صورت دیرزاد، ماهیت چینه‌کران و بافت و ساخت پرکننده فضای خالی در سنگ میزبان کربناتی رخداده است. کانی‌شناسی بخش درون‌زاد شامل کالکوسیت، کالکوپیریت، پیریت، اسفالریت، گالن، انارژیت، باریت و کلسیت و کانیهای بخش برون‌زاد شامل مالاکیت، آزوریت، کوولیت، کریزوکولا، کالکوسیت، سروزیت، اسمیت‌زونیت، مس طبیعی، هماتیت، گوتیت و لیمونیت می‌باشد. سنگ میزبان کربناتی در اطراف زون‌های کانه‌دار متحمل دگرسانیهای دولومیتی‌شدن و کلسیتی‌شدن شده است. مس به‌عنوان عنصر اصلی ذخیره (با میانگین 28/20 درصد وزنی) و پس از آن عناصر روی (با میانگین تقریبی 1 درصد وزنی) و آرسنیک (با میانگین تقریبی 1 درصد وزنی) می‌باشند. مطالعات سیالات‌درگیر روی کانی باریت نشان می‌دهد سیال کانه‌دار سولفیدی دارای محدوده دمای همگن شدن بین 259 تا 354 درجه سانتی‌گراد و میزان شوری بین 8 تا 13 درصد وزنی معادل NaCl می‌باشد. سیال کانه‌دار در مراحل پایانی کانی‌سازی با آبهای جوی دچار اختلاط شده و فاز تأخیری غیر سولفیدی کلسیتی با محدوده دمای نسبتا پایین ‌(78 تا 112 درجه سانتی‌گراد) و درجه شوری پایین (بین 3 تا 6 درصد وزنی معادل NaCl) را تشکیل داده است. محدوده مقادیر 34Sδ کانی‌ باریت کانسار باقرق بین 13+ تا 14+ در هزار بوده در حالی‌که محاسبه مقدار 34Sδ مربوط به سیال کانه‌دار پس از تصحیح دمایی بین 7- تا 8- در هزار به‌دست آمد. منشأ گوگرد باقرق با توجه به شباهت ایزوتوپ باریت با سولفات‌های دریایی کرتاسه، احتمالا از لایه‌های تبخیری این دوره زمانی تأمین شده است. این سولفا‌ت‌ها توسط فرآیند‌های ترموشیمیایی به‌صورت بخشی به گوگرد احیایی با مقدار ایزوتوپی سبک‌تر (حدود 21 در هزار) تبدیل و جهت ته‌نشست سولفیدها مورد استفاده قرار گرفته است. کانسار باقرق با توجه به خصوصیاتی همچون سنگ میزبان کربناته، غیاب فعالیت آذرین، بافت پرکننده فضای خالی، دگرسانی دولومیتی،کانی‌شناسی، ژئوشیمی ماده‌معدنی (وجود As و Sb بالا و عدم حضور Bi)، داده‌های دماسنجی و مقادیر ایزوتوپ گوگرد، شباهت زیادی با کانسارهای مس با سنگ میزبان کربناته در افریقا و به‌ویژه نوع سومب (Tsumeb) در نامیبیا نشان می‌دهد. کانسار باقرق احتمالا مرتبط با سیالات دگرگونی آزاد شده در حین فازهای کوه‌زایی مرتبط با بسته‌شدن اقیانوس نئوتتیس می‌باشد.

In Situ Optimizing Thin Semiconductor Passive Films of Bismuth Oxides and Sulfides under Visible Light Illumination for Enhanced Photoelectrochemical Performances

We report here an in situ method to monitor and optimize formation of thin semiconductor passive films of bismuth oxides and sulfides for enhanced photoelectrochemical performances. It was conducted by cyclic voltammetry under visible light illumination in a mixed solution of Na2SO3 and Na2S. Electrooxidation and sulfurization of Bi electrodes occurred simultaneously during the potential cyclings between −1 V and 0 V (vs. Hg|Hg2SO4(s)|K2SO4 (saturated)), and the semiconductor passive film with an appropriate thickness was formed effectively under light illumination. In comparison with the composite film of Bi2S3/Bi2O3 loaded on conductive glass, enhanced photoelectrochemical performances were observed in much wider potential ranges on the prepared semiconductor passive film due to its very compact coverage. Higher anodic photocurrent density was obtained from −1 V to 10 V on the semiconductor passive film prepared under light illumination than in dark, and under galvanostatic operation the anodic potential went back and forth between −1.1 V and 9.8 V rapidly while the visible light illumination was on and off. We expect that these photoelectrochemical characteristics will find applications in photoelectrochemical hydrogen production, photodetectors and photoswitches.

Comparative study of Sb2S3, Bi2S3 and In2S3 thin film deposition on TiO2 by successive ionic layer adsorption and reaction (SILAR) method

Sensitization of nanoporous TiO2 with Sb2S3, Bi2S3, and In2S3 thin films deposited at the room temperature by using the simple and inexpensive SILAR method is presented. Structural, morphological, and optical characterization of thin films prepared by this method were conducted by X-ray diffraction (XRD), scanning electron microscopy (SEM), and diffuse reflectance spectroscopy (DRS). The photocurrent response of the thin films was studied with a three electrode photoelectrochemical cell. The influence of the number of deposition cycles on the optical properties of the thin films was investigated, and the structural and morphological studies revealed the formation of polycrystalline thin films with an orthorhombic structure for Sb2S3 and Bi2S3 system, whereas a cubic structure was found for the In2S3, which had a cluster-like surface morphology and uniform distribution. Optical studies showed that enhancing TiO2 light absorption in the visible range is possible by the incorporation of antimony, bismuth, and indium sulfides. Photocurrent measurements showed that photons are absorbed by metal sulfide and electrons injected to TiO2.

SUBSTITUTION OF Bi FOR Sb AND As IN MINERALS OF THE TETRAHEDRITE SERIES FROM REDZINY, LOWER SILESIA, SOUTHWESTERN POLAND

Various members of the tetrahedrite series, including Bi-rich species, have been found in products of hydrothermal mineralization disseminated in contact zones of the dolomitic marble deposit at Redziny, Western Sudetes, Poland. The occurrence is important owing to the opportunity to observe changes in composition of the minerals occurring in different assemblages formed at varyious temperatures. Bismuth-rich varieties (up to 15.86 wt.%, 1.36 apfu , in tetrahedrite, and up to 18.41 wt.%, 1.51 apfu , in tennantite) commonly form inclusions in, and intergrowths with, other sulfides. A small inclusion with Bi > As and Sb, and with the stoichiometry of “annivite”, the Bi analogue of tetrahedrite and tennantite not yet approved by CNMNC IMA, was recognized in association with stannoidite + mawsonite + chalcopyrite + native Bi. Distinct correlations involving Fe, Ag, Cu and Sb at higher temperatures (to about 280°C) and Zn, Cu and As at lower temperatures suggest the predominance of the end-member freibergite, (Ag 6 Cu 4 )Fe 2 Sb 4 S 13– x , at about 340°C, grading to Ag- and Bi-bearing tetrahedrite, (Cu 7 Ag 3 )(Fe,Zn) 2 (Sb,Bi) 4 S 13 , then to Ag-poor, Bi-bearing tennantite, Cu 10 (Zn,Fe) 2 (As,Bi) 4 S 13 , and finally to Bi-free, Zn-bearing tennantite, Cu 10 Zn 2 As 4 S 13 , which predominates at temperatures below 200°C. The sequence of the tetrahedrite series at Redziny indicates that the varieties richest in Bi crystallized at temperatures of 300–230°C together with bismuth sulfides and native Bi, being preceded by numerous sulfosalts of bismuth, especially those enriched in Ag, such as gustavite, pavonite, benjaminite, berryite and giessenite. The substitution of Bi for Sb in tetrahedrite, coupled with an increase in the Fe and Ag contents and depletion in Zn, leads to an increase, and in an extreme case even to a predominance, of Ag-bearing “annivite”, (Cu 6 Ag 4 ) Fe 2 Bi 4 S 13 , at a temperature of about 280°C. This is promoted by high Bi activity and temporal concentration of Cu 6 [Cu 4 (Fe,Zn) 2 ] Bi 4 S 13 in hydrothermal solutions.