title: Visible light driven mineralization of spiramycin over photostructured N-doped TiO2on up conversion phosphors.
abstract: A novel visible light-active photocatalyst formulation (NdT/OP) was obtained by supporting N-doped TiO2(NdT) particles on up-conversion luminescent organic phosphors (OP). The photocatalytic activity of such catalysts was evaluated for the mineralization process of spiramycin in aqueous solution. The effect of NdT loading in the range 15-60wt.% on bulk and surface characteristics of NdT/OP catalysts was investigated by several chemico-physical characterization techniques. The photocatalytic performance of NdT/OP catalysts in the removal of spyramicin from aqueous solution was assessed through photocatalytic tests under visible light irradiation. Total organic carbon (TOC) of aqueous solution, and CO and CO2gas concentrations evolved during the photodegradation were analyzed. A dramatic enhancement of photocatalytic activity of the photostructured visible active NdT/OP catalysts, compared to NdT catalyst, was observed. Only CO2was detected in gas-phase during visible light irradiation, proving that the photocatalytic process is effective in the mineralization of spiramycin, reaching very high values of TOC removal. The photocatalyst NdT/OP at 30wt.% of NdT loading showed the highest photocatalytic activity (58% of TOC removed after 180min irradiation against only 31% removal after 300min of irradiation of NdT). We attribute this enhanced activity to the high effectiveness in the utilization of visible light through improved light harvesting and exploiting. OP particles act as "photoactive support", able to be excited by the external visible light irradiation, and reissue luminescence of wavelength suitable to promote NdT photomineralization activity.
authors.affiliation: University of Salerno, Department of Industrial Engineering, Via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
authors.forename: Olga
authors.initials: O
authors.lastname: Sacco
authors.affiliation: University of Salerno, Department of Industrial Engineering, Via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy. Electronic address: vvaiano@unisa.it.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Vaiano
authors.affiliation: University of Salerno, Department of Industrial Engineering, Via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
authors.forename: Diana
authors.initials: D
authors.lastname: Sannino
authors.affiliation: University of Salerno, Department of Industrial Engineering, Via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Ciambelli
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D007700:Kinetics; D008027:Light; D008956:Models, Chemical; D009584:Nitrogen / Q000737:chemistry*; D010782:Photolysis; D015572:Spiramycin / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D015572:Spiramycin; D014025:Titanium; D009584:Nitrogen
keywords: Photocatalysis; Spiramycin mineralization; Up-conversion phosphors; Visible light, N-doped TiO(2)