Phase transfer-based synthesis of HgS nanocrystals

Abstract

Phase transfer techniques possess remarkable advantages for the synthesis of inorganic nanomaterials. In contrast to the abundant reports on the preparation of noble metal nanoparticles using phase transfer, the number of semiconductor nanocrystals syntheses based on phase transfer techniques is still limited. Herein, we report a systematic study of the phase transfer-based synthesis of HgS nanocrystals, including the tuning of their morphology/shape by either solvent choice or temperature. This strategy involves the transfer of Hg(ii) ions from aqueous solution to toluene, oleic acid or oleylamine and subsequent sulfidation at room or elevated temperature. Furthermore, we have extended this phase-transfer based strategy to the fabrication of HgS-Au nanocomposites. The studies in this work might provide a facile route for producing HgS nanocrystals with desirable properties and offer an effective strategy to investigate the influence of the morphology of HgS on the physical/chemical properties of various HgS-based materials.

Highly Fluorescent, Near-Infrared-Emitting Cd2+-Tuned HgS Nanocrystals with Optical Applications

“…Until now, the as-reported HgS NCs exhibited no emission or weak emission, ,,− clearly indicating that a layer of organic ligands ,− or a layer of inorganic material was not powerfully enough to pacify the surface of HgS NCs. In our study, HgS-core NCs were first made by adding Na 2 S to the Hg-GSH complex (1:1) at pH 9.5, and then Cd 2+ ions were introduced with an attempt to tune the band-gap structure of HgS NCs and enhance their luminescence efficiency.…”

“…Scientific attention has been paid to the study of β-HgS NCs. Previous studies on HgS nanoparticles usually resulted in irregular and large HgS particles. ,− Morphology-controlled HgS nanoparticles were well synthesized via effectively adjusting the reactivity of mercury ions. ,− By controlling the reactivity of Hg 2+ and the particle size, photoluminescent HgS NCs were successfully fabricated though reverse micelles, an aqueous route, ,− and an organometal approach . Unfortunately, despite much synthesis effort made in the fabrication of HgS NCs, the obtained HgS NCs all exhibited weak emission with a maximum photoluminescence quantum yield (PL QY) of 5% and poor thermal stability. ,− Even if the overgrowth of a wide-band-gap CdS layer on HgS NCs was achieved, the emission was still weak with broad and poorly resolved spectra .…”

Mercury Chalcogenide Quantum Dots: Material Perspective for Device Integration

“…The nanocrystal size was controlled through the Hg/S ratio. Later, Han et al 135 adapted the phase transfer synthesis from gold to HgS nanocrystals. Mercury was transferred from the aqueous phase to the organic phase by dissolving mercury nitrate and dodecylamine in water/ethanol.…”

Biosynthesis of micro‐ and nanocrystals of Pb (II), Hg (II) and Cd (II) sulfides in four Candida species: a comparative study of in vivo and in vitro approaches

“…NCs chemically synthesized from Cd:HgS/CdS have proved to be stable and highly fluorescent compared with the HgS NCs also obtained by chemical synthesis (Yang et al ., ). Other research groups have used other synthesis strategies for AgS NCs, but all with a high degree of complexity (Han et al ., ; Jeong et al ., ). The PbS NCs were chemically synthesized, and like HgS NCs, the chemical synthesis was also complex and needed to be well controlled in vitro (Lim et al ., ; Lee et al ., ).…”