Cu/ZnS microspheres have been successfully synthesized using microwave irradiation method without using any template. Cu/ZnS microspheres were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), inductively coupled plasma optima optical emission spectrometer (ICP-OES), X-ray photoelectron spectroscopy (XPS), diffused reflectance spectroscopy (DRS), and electrochemical impedance spectroscopy (EIS) methods. Tuning of band gap from 3.43 to 236 eV was successfully achieved upon doping copper (0-10%) into ZnS. The photocatalytic activity was investigated by photosplitting of water containing an aqueous Na2S solution under visible light irradiation. Among the prepared photocatalysts, the hydrogen evolution rate reaches the maximum of about 973.1 mu mol h(-1) g(-1) for 2.0 mol% Cu2+ ion doped ZnS. Moreover, Cu/ZnS microspheres were found photocatalytically stable during the 48 h test runs. (C) 2015 Elsevier Ltd. All rights reserved.