Using the adsorption method, small amounts of rhodium ion (Rh3+) or copper ion (Cu2+) were loaded on nanocrystalline titanium(IV) oxide (TiO2) with various physical properties prepared by the HyCOM (hydrothermal crystallization in organic media) method and subsequent calcination at various temperatures. In photocatalytic degradation of 2-propanol under visible light irradiation, Rh3+-modified HyCOM-TiO2 samples exhibited higher levels of activity than did Cu2+-modified HyCOM-TiO2 samples and the nitrogen-doped TiO2 sample. The Rh3+-modified HyCOM-TiO2 samples showed a volcano-like tendency with calcination temperature, suggesting that the balance of surface area and crystallinity of TiO2 is important in an Rh3+/TiO2 photocatalyst. Rutile-type TiO2 modified with Cu-2 exhibited the highest level of activity among the Cu2+/HyCOM-TiO2 samples. (c) 2010 Elsevier B.V. All rights reserved.