Non toxic SnS quantum dots (QDs) were successfully deposited on mesoporous titanium dioxide (TiO2) electrodes. The size of these SnS QDs was controllable by the successive ionic layer absorption and reaction method. The color and photoelectrochemical response of these electrodes strongly depended on the size of the SnS QDs. The SnS QDs are composed of non-toxic and inexpensive elements and expected to be applied for efficient photo-electrochemical devices. (C) 2011 Elsevier B. V. All rights reserved.