Sonication-Assisted Synthesis of β-Mercuric Sulphide Nanoparticles

The nanoscale semiconductor β‐mercuricsulphide (HgS) has promising applications in electronicand optical fields. Continued development of synthesismethods is needed to expand approaches that produceuniform particles, while avoiding reagents of hightoxicity and ecological impact. A solvent‐based approachwas developed using mercuric chloride and elementalsulphur as the mercury and chalcogenide sources.Ethanol was used as the solvent and sodium hydroxide asthe hydrolysis reagent. Use of mild sonication resulted insmaller particles (average 11nm diameter) than withoutsonication treatment (average 17nm diameter) andcontinuous nitrogen purging reduced the surface oxygencontent of the particles from approximately 25% to 6%.Particle characterization methods included TEM, XRD,XPS, UV‐visible absorbance spectroscopy and DLS. Thenanoparticles were typically spheres of 10‐15nm indiameter. Aggregates formed in aqueous solutionstended to be in the range of 100nm or more. The overallprocess can be performed simply at room temperatureand is comparatively free of toxic chemical hazards. Theprocess does not include surfactants or other stabilizersthat could potentially contaminate the nanocrystals. Inprinciple, the method could be applied to synthesis ofother metal chalcogenide nanoparticles