TiO2 nanospheres with diameters mostly in the range of 20-200 nm are prepared by using cathodic plasma electrolysis at low voltage of 70 V. It is found that the low voltage could efficiently depress the particle sizes and their distribution, and result in more anatase phases. The nanospheres have an excellent optical absorption from 240 nm to 2600 nm. (c) 2012 Elsevier Inc. All rights reserved.