One-pot Sonochemical Synthesis of Hg–Ag Alloy Microspheres from Liquid Mercury

Abstract

Metallic mercury has always attracted much attention in various fields because of its unique characteristic of forming amalgams. Here, different phases of pure crystalline Hg-Ag amalgam microspheres are synthesized by ultrasonically reacting liquid mercury with an aqueous solution of silver nitrate. Sonicating different molar ratios of liquid metallic Hg with AgNO results in the formation of pure crystalline phases of solid silver amalgams with uniform morphology. The resulting Hg-Ag amalgams from various compositions after sonication are physically characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and Differential Scanning Calorimetry (DSC). The XRD of the amalgams obtained from the molar ratios of Hg:Ag (1:1.5) and Hg:Ag (1.5:1 and 2:1) match the Schachnerite and Moschellandbergite phases, respectively, whereas the Hg-Ag amalgam prepared from a 1:1Hg:Ag molar ratio results in a mixture of the Schachnerite and Moschellandbergite phases. The obtained amalgam microspheres are between 6 and 10µm in size. The detailed thermal and chemical behaviour of the Ag-Hg systems is also investigated.

Magnetic Fe3O4-Ag0 Nanocomposites for Effective Mercury Removal from Water

“…Hg 2+ + 0. In the case of Fe3O4-Ag 0 nanocomposites, the appearance of a new peak at around 17º probably indicated the formation of an Hg-Ag amalgam (moschellandbergite phase, Ag2Hg3) [48]. The absence of literature on the removal of Hg 2+ from aqueous solutions by the use of Fe3O4-Ag 0 nanocomposites is difficult to support this conclusion.…”

Sonochemical catalysis as a unique strategy for the fabrication of nano-/micro-structured inorganics

“…Later on, they also achieved pure crystalline Hg-Ag amalgam microspheres with uniform morphology by ultrasonically reacting liquid mercury with an AgNO 3 aqueous solution ( Figure 6). [62] In the study of Kwon and coworkers, [63] another kind of bimetallic alloy Pd n M (n = 1 for M = Mn, Fe, and Co; n = 1, 2, and 3 for M = Ni) nanoparticles (NPs) were synthesized on carbon supports by the sonochemically catalytic reactions of Pd(acetylacetonate) 2 2 and Pt(acetylacetonate) 2 , where the nanoparticles had Pt-enriched surface with Pd and Co forming the core. [64] Certainly, the other sonchemical synthesis of bimetal (e.g., Au/Ag, Au/Pd, Pt/Ru) or even multi-metal nanomaterials (e.g., NiCoPd, Pt/PdNiMo) has been reported as well.…”

Synthesis of biosourced silica–Ag nanocomposites and amalgamation reaction with mercury in aqueous solutions

“…Ag n + Hg 2+ ↔ Ag (n−2) Hg + 2Ag + Harika et al [52] studied the amalgamation reaction by ultrasonically reacting liquid mercury with an aqueous solution of silver nitrate. Although the formation and role of silver nanoparticles is not discussed, the authors observed schachnerite and moschellandsbergite and mixed phases with molar Hg/Ag ratios of 0.665 to 2.…”

“…There are only few publications on the formation of Hg-Ag amalgams at the nanoscale [52]. Besides the complexity of the reaction, another issue is that the identification of the amalgams by XRD in small concentrations is difficult and only few weak peaks are typically observed; see for example Katok et al [39], who first investigated hyperstoichiometry in a similar system and identified schachnerite.…”

“…The same amalgam was observed by Henglein and Brancewicz [50], but the reaction was between Ag + and Hg 2+ solutions in the presence of a reducing agent. A comprehensive study on the formation of amalgams between bulk Hg o and Ag nanoparticles is that by Harika et al [52]. The results showed that depending on the initial Hg/Ag molar ratios, no amalgam, schachnerite, moschellandsbergite and mixed schachnerite/moschellandsbergite can be formed.…”