The use of chemical methods to produce coatings with good spectrally selective properties is described. Sol-gel and dipping techniques were combined to fabricate thickness-sensitive solar-selective absorbing coatings based on titanium oxide combined with carbon black (TiO2/CB) and carbon nanotubes (TiO2/CNT) on top of stainless-steel substrates. The low to high reflectance transition (;,T) observed in the tandem system based on TiO2/CB films was smooth and red shifted when compared to the sharp transition observed in systems based on mesoporous TiO2/CNT films. Mesoporosity of the oxide was controlled by the use of polymeric surfactants with different molecular weights, causing a significant blue shift in;T as the molecular weight increases. These films were characterized by X-ray diffraction and UV-vis light absorption spectroscopy. (c) 2007 Elsevier B.V. All rights reserved.