ZnS nanoparticles self-assembled from ultrafine particles and their highly photocatalytic activity

ZnS nanoparticles self-assembled from ultrafine particles (2–6 nm) have been synthesized for the first time by the composite molten salt method. UV–vis reflectance spectrum and photoluminescence of the ZnS nanoparticles were investigated. The narrowed band gap of the ZnS nanoparticles was found owing to novel crystal structure formed from a lattice-matched ‘coherent interface’ of the agglomerated ultrafine particles. Photocatalytic degradation of methyl orange by the nanoparticles shows much better photocatalysis than that by the commercial ZnS powder under simulated sunlight irradiation.