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Nanogenerators and Self-Powered Nanosensors
Published in Vinod Kumar Khanna, Nanosensors, 2021
To fabricate this sensor, Ag2Te NWs are synthesized by a two-step chemical method: Synthesis of Tellurium Nanowires: this is done by a solution-phase chemical reduction approach using a tellurium dioxide solution in hydrazine containing sodium dodecyl sulfate (SDS). After a reaction time of 2 h, the Te NWs have a diameter of 18 nm and are 820 nm long.Synthesis of Silver Telluride Nanowires: the Te NWs are redispersed in SDS solution and silver nitrate solution is added. The tellurium NWs are converted into Ag2Te NWs through a redox reaction between silver ions and tellurium atoms. The Ag2Te NWs have an average diameter of 21 nm.
Thermoelectric and Microsystems Perspectives and Opportunities and Opportunities
Published in Madhu Bhaskaran, Sharath Sriram, Krzysztof Iniewski, Energy Harvesting with Functional Materials and Microsystems, 2017
The design optimization and design performance analysis techniques discussed can generally be used to design each of the sections. However, there are unique and complex design trade-offs associated with the amount of heat transferred, the conversion efficiency, and power generated in each section. These must be fully evaluated in any TE energy recovery system design to achieve the optimum performance. Figure 3.6 illustrates some of these trade-offs in a simple dual-sectioned design shown in Figure 3.5. The dual-sectioned design creates significant design trade-offs between power output and efficiency in each section when seeking the optimum overall system performance, whether that is maximum overall system efficiency or maximum system power output. There are two sets of maximum efficiency–power curves in Figure 3.6; one for section 1 designs using lead–antimony–silver–telluride (LAST) materials and a second for section 2 designs using bismuth telluride materials in Figure 3.5. The maximum efficiency–power curves identify the loci of maximum efficiency designs defined by techniques in Equations (3.11)–(3.13). The resulting maximum efficiency–power maps in each section are produced by the coupled interdependence of the TE device design and hot-side and cold-side heat exchangers in sections 1 and 2.
Properties of the Elements and Inorganic Compounds
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
Name Polymidite Portlandite Powellite Protoenstatite Proustite Pseudowollastonite Pyrargyrite Pyrite Pyrolusite Pyrope Pyrophyllite Pyroxmangite Pyrrhotite Quartz () Quartz () Rammelsbergite Realgar Retgersite Riebeckite Rutile Safflorite Fe-Sanidine Sanmartinite Sapphirine Schorl Selenium (gray) Sellaite Senarmontite Shandite Shortite Siderite Silicon Sillimanite Silver Silver telluride I Silver telluride II Fe-Skutterudite Ni-Skutterudite Smithsonite Sodium melilite Sperrylite Spessartite Sphalerite Sphene Spinel Spodumene Spodumene () Staurolite Sternbergite Stibnite Stilleite Stishovite Stolzite Stromeyerite Sulfur (monoclinic) Sulfur (rhombohedral) Formula Crystal system cubic hexagonal tetragonal orthorhombic rhombohedral triclinic rhombohedral cubic tetragonal cubic monoclinic triclinic hexagonal hexagonal hexagonal orthorhombic monoclinic tetragonal monoclinic tetragonal orthorhombic monoclinic monoclinic monoclinic rhombohedral hexagonal tetragonal cubic rhombohedral orthorhombic rhombohedral cubic orthorhombic cubic cubic cubic cubic cubic rhombohedral tetragonal cubic cubic cubic monoclinic cubic monoclinic tetragonal monoclinic orthorhombic orthorhombic cubic tetragonal tetragonal orthorhombic monoclinic rhombohedral Structure type spinel cadmium iodide scheelite Z a/Å 9.480 3.5933 5.226 9.25 10.816 6.90 11.052 5.4175 4.388 11.459 5.14 7.56 3.440 4.9136 4.999 4.757 9.29 6.782 9.729 4.5937 5.231 8.689 4.691 9.96 16.032 4.3642 4.621 11.152 5.576 4.961 4.6887 5.4305 7.4843 4.0862 5.29 6.585 8.1814 8.3300 4.6528 8.511 5.968 11.621 5.4093 7.07 8.080 9.451 7.5332 7.90 11.60 11.229 5.6685 4.1790 5.4616 4.066 11.04 10.818
Oxidative Decomposition of Silver Telluride (Ag2Te) Using Hypochlorite in Different Acid Environments
Published in Mineral Processing and Extractive Metallurgy Review, 2022
V.M. Rodríguez-Chávez, J.C. Fuentes-Aceituno, F. Nava-Alonso
The depletion of easily leachable gold and silver deposits has forced the mining industry to explore new processing alternatives to recover the precious metals from different ores. Among the most important silver phases, it is possible to find pyrargyrite, proustite, stephanite and silver telluride (Paterson 1990). The most common mineral phase of silver telluride is hessite (Ag2Te), and it is frequently associated with some gold tellurides, e.g. calaverite (AuTe2), petzite (Ag3AuTe2), krennerite (AuTe2), montbrayite (Au2Te3) and kostovite (CuAuTe4) (Adams 2016). However, according to Celep et al. (2014), these important silver mineral phases present a very low leaching kinetics in cyanide solutions. Furthermore, Wang and Forssberg (1990) reported that gold and silver telluride and selenide species are stable in the presence of cyanide, which suggests that direct leaching of gold and silver with cyanide is probably ineffective. The reported results demonstrate that the leaching kinetics is very slow compared to native gold and electrum (Cornwall and Hisshion 1976; Henley, Clarke and Sauter 2001; Jayasekera, Ritchie and Avraamides 1991; Johnston 1933; Marsden and House 2006; Padmanaban and Lawson 1991). As can be seen, the refractoriness of these type of minerals becomes an important challenge for the scientific and engineering viewpoint. Jha (1987) and Zhang et al. (2010) mentioned that refractoriness of some minerals including the telluride species can be usually solved by modifying the cyanidation conditions or providing an oxidation pretreatment. Roasting prior to cyanidation was the almost universal practice in old days; however, severe environmental regulations related to the toxic emissions have motivated the researchers to develop alternative leaching systems (Hiskey and Atluri 1988). In the case of gold telluride cyanidation, Haque (2007), reported the possibility to accelerate its dissolution using pre-treatments such as: thermal oxidation, roasting, chemical oxidation, (such as acid leaching, alkaline or acid pressure leaching or biological oxidation). In the case of the chemical oxidation of refractory ores, various types of oxidants have been studied e.g. ozone, hydrogen peroxide, permanganate, chlorine, bromine cyanide, Care`s acid, perchlorate, hypochlorite, ferric ion in acid media and oxygen (Canning and Woodcock 1982).