We proposed the trituration of the non-aqueous reaction mixture as a synthesis route for PEG-capped CdS nanopowders, having the advantage of obtaining a more uniform powder, with smaller particle dimension, high specific surface area and an unexpected growing of photocatalytical properties compared with PEG-capped CdS nanopowders obtained by typical chemical precipitation method. The CdS nanopowders were characterized by FT-IR spectroscopy, UV-visible diffuse reflectance spectroscopy, N-2 physical adsorption, transmission electron microscopy and electron diffraction. The optical properties of cadmium sulfide nanopowders were estimated by means of the band gap energy, and the catalytic properties were tested in the Congo red degradation process, under visible light irradiation. The experimental results evidenced an improvement of the properties for nanopowder obtained by trituration technique, meaning a smaller mean diameter (about 4.69 nm), a higher specific surface area (56 m(2) g(-1)) and a higher efficiency in photocatalytic degradation of an azo dye. (C) 2014 Elsevier B.V. All rights reserved.