The potential of chemical industrial and academic wastes as a source of supported photocatalysts

Industrial galvanic bath residuals, residual silver-containing solutions from photography classes, residual metal-containing solutions from academic analytical chemistry classes, and residual Ziegler Natta catalyst slurry from a petrochemical plant were employed as sources for photocatalysts. The residues were impregnated on silica, with subsequent calcination. The solids were characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), Rutherford backscattering spectrometry (RBS), diffuse reflectance spectroscopy in the ultraviolet (DRS-UV), small-angle X-ray scattering (SAXS), nitrogen porosimetry and zeta potential (ZP) measurements. The catalysts contained Zn, Ti,Ag, Cr or Cu. All the systems presented also included carbon in their composition. Metal content ranged from 0.01 to 0.60 wt%. The systems were evaluated by the photodegradation of Rhodamine B (RhB). For comparative reasons, P25 (Degussa) was also employed as a catalyst. The supported catalysts resulting from the residue of the petrochemical industry achieved the highest percentage of the dye degradation in the ultraviolet (67%) and visible (61%) radiation, while the commercial P25 achieved 93% and 14% for ultraviolet and visible radiation, respectively. (C) 2014 Elsevier B.V. All rights reserved.