Electrolysis of a molten semiconductor

Abstract

Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides.

Superconductivity in an Al-twisted bilayer graphene-Al junction device

“…The Raman spectroscopy and transmission electron microscopy (TEM) measurements were also applied to confirm the structural properties of the tBLG films. In the Raman spectra shown in Figure 1a, we can see an enhanced intensity of the G-band with respect to the 2D band, a feature of tBLG arising from matching of the laser energy with the energy of van Hove singularities in tBLG [27][28][29] . The inset of Figure 1a shows a high resolution TEM image of a CVD-grown tBLG sample, where a moiré pattern is clearly observed, which further confirms that the sample is a twisted bilayer film.…”

Low‐Temperature Molten‐Salt Production of Silicon Nanowires by the Electrochemical Reduction of CaSiO3

“…This approach has two major advantages over carbothermic reduction: The use of molten salts significantly reduces the reaction temperature (850 vs. ca. 1700 °C), and Si is produced in a single step .…”

In-situ anodic precipitation process for highly efficient separation of aluminum alloys

“…Electrochemical technologies are widely used in synthesis 5 – 7 , metal extraction 8 , 9 , energy conversion 10 – 13 , and separations 14 , 15 . Due to unique features enabled by physical separation of the cathode and anode, an electrochemical technique can be tailored for specific components, often with high efficiency and product purity, and at low cost 16 .…”