Improving TiO_2 activity in photo-production of hydrogen from sugar industry wastewaters

摘要

A series of TiO_2 photocatalysts dispersed on SiO_2, modified with metals (Mn, Cr, V) or non-metals (N or S) or covered with Au nanoparticles were prepared by incipient wetness impregnation, impregnation with urea or thiourea, and deposition-precipitation, respectively. The photocatalysts where characterized by chemical analysis, X-ray diffraction (XRD), diffuse reflectance UV-Vis spectroscopy (DR-UV-Vis) and Fourier transform infrared spectroscopy (FTIR). The photocatalytic activity was checked in the photo-generation of hydrogen from sugar solutions. The nature of the modifying species was found to influence the photoactivity and N and S led to more effective catalysts than metals. This behavior was attributed to the fact the N and S are less effective in forming recombination centers compared with the metals.