Nb-doped titania nanopowders active under UV and visible light were used as supports of platinum and tested in the photo-production of hydrogen using methanol as sacrificial agent in liquid phase. Samples were characterized using X-ray diffraction and photoelectron spectroscopy, UV-vis and photoluminescence spectroscopies, electron paramagnetic resonance, and transmission electron microscopy. The catalytic performance was evaluated taking into account the measurement of the corresponding reaction rates and the computation of the quantum efficiency values. Optimization of the catalytic output upon UV and visible excitation was carried out as a function of the Nb content of the material and using an experimental design taking as factors the methanol:water ratio, and catalyst concentration at liquid phase. The performance of the materials and the optimum for a catalyst containing a 2.5 mol% of Nb upon UV, visible light and sunlight was examined. The characterization results concerning both the charge carrier species recombination and the fate of such species at the catalytic surface were used to elucidate the physico-chemical roots for maximizing activity. (C) 2017 Elsevier B.V. All rights reserved.