Showing papers on "Ammonium tetrathiomolybdate published in 2013"

Aqueous Medium Synthesis Route for Randomly Stacked Molybdenum Disulfide

Abstract: Synthesis of poorly crystalline, randomly oriented rag-like structures of molybdenum disulfide has been reported starting from aqueous solutions of ammonium molybdate, and thioacetamide in presence of sodium dodecyl sulfate via calcination of the amorphous precipitates, obtained through acidification of the in situ generated intermediate of ammonium tetrathiomolybdate. X-ray photoelectron spectroscopy, UV-visible spectroscopy, and X-ray diffraction of the calcined samples reveal the formation of single-phase MoS2, while the amorphous precipitates have been found to be a mixture of Mo2S5, MoS3, and a trace amount of H2MoS4. Highly folded and disordered layers of rag-like MoS2 have been confirmed through high-resolution transmission electron microscopy. The electrical conductivity for the cold pressed pellet of the MoS2 sample is found to be significantly higher than that of 2H-MoS2 and increases further on annealing.

Ammonium Tetrathiomolybdate: A Versatile Catalyst for Hydrogen Evolution Reaction from Water under Ambient and Hostile Conditions

Abstract: The lack of catalysts that can selectively reduce protons to produce hydrogen from water in the presence of oxygen and other conventional inhibitors of hydrogen evolution reaction (HER) has been a fundamental problem stalling the development of a practical hydrogen economy. Ammonium tetrathiomolybdate (ATM), a common laboratory reagent, spontaneously assembles on Au electrodes. Atomic force microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy data indicate formation of multiple layers of ATM which are stable over a wide pH range for days. These assemblies can produce hydrogen with very low onset potentials. It shows a turnover rate of 1.4 s–1 and turnover number >5 × 104 in pH 7 at 180 mV overpotential. The pH dependence of the peak potential suggests that the generation of H2 from water proceeds likely via a ligand based proton coupled electron transfer process which precludes inhibition by O2. The ATM functionalized Au electrodes are found to efficiently catalyze HER in saline ...

Enhanced Performance of NaTaO3 Using Molecular Co-Catalyst [Mo3S4]4+ for Water Splitting into H2 and O2.

Abstract: The photocatalytic activity of NaTaO3 for water splitting into H2 and O2 is significantly improved by using the molecular co-catalyst [Mo3S4(OH2)9]Cl4 (synthesized by reduction of ammonium tetrathiomolybdate with sodium borohydride).