A facile decomposition reaction was successfully developed to synthesize superfine β-HgS nanoparticles in single step process under mild condition. This report describes the use of thioglycolic acid as both reducing and stabilizer agent to produce superfine nanoparticles and no secondary chemical reducing agent is required. Semiconductor nanoparticles show novel opticalpro perties due to the large number of surface atoms and/ or the three-dimensional confinement of electrons. Decrease in particle size changes the order of confinement of the electrons and the electronic structure of the solid state. The optical properties and quantum-confined effect of the β-HgS nanoparticles are confirmed by the ultraviolet- visible (UV–vis), DRS analysis and photoluminescence analysis. Diffuse reflectance spectroscopy shows the large blue shift of band gap for as-synthesized nano particles toward bulk state.
