ZnS nanospheres with rough surface were synthesized by using a micro-emulsion-assisted solvothemal process. The molar ratio of [water]/[surfactantl played an important role in controlling the size of the ZnS nanospheres. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), field emission-scanning electron microscope (FE-SEM), and selected area electron diffraction (SAED) were used for the characterization of the resulting ZnS nanospheres. A possible formation mechanism was proposed. These ZnS nanospheres exhibited a good photocatalytic activity for degradation of an aqueous p-nitrophenol solution and the total organic carbon (TOC) of the degradation product has also been investigated. (C) 2007 Elsevier Ltd. All fights reserved.