Submicron- and nano-scale cuprous oxide particles derived from copper acetate and copper gluconate complexes were synthesized via a photochemical route in polar media without further reducing agents. The morphology, composition, and phase structure of as-prepared Cu2O were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS). Factors affecting the morphology and size of the Cu2O products have been examined in detail to determine the optimum parameters to achieve a controllable synthesis. The results show that solvent is the most key factor in size- and shape-control of the Cu2O products. Water induces the formation of submicron particles, while alcohol results in nanoscale particles. The photochemical growth of Cu2O particles can be fine tuned by varying the parameters of the reaction procedure, e.g. solvent, precursor ligand, and additive. The IR results indicate that these Cu2O particles result from the photoinduced intramolecular electron transfer between metal and ligand. The method can be easily controlled and is expected to be applicable for the preparation Of cuprous oxide supported catalysts. (C) 2009 Elsevier Inc. All rights reserved.