title: Effect of thermal and mechano-chemical activation on the photocatalytic efficiency of ZnO for drugs degradation.
abstract: Over the past few years, pharmaceutical drugs have been considered as emerging pollutants due to their continuous input and persistence in the aquatic ecosystem even at low concentrations. They have been detected worldwide in environmental matrices, indicating their ineffective removal from water and wastewaters using conventional methods. In this study we present photocatalytic purification of water from Acetaminophen and Chloramphenicol by ZnO upon UV-light illumination. Commercial ZnO powders are activated thermally (annealed at different temperatures-100, 200, 300, 400 and 500 °C for 1 h) and mechanically (treated for 5, 15, 20, 30, 40 and 60 min). The mechonoactivation is performed varying the atmosphere in air, or in suspension of ethanol and methanol. The changes in the studied material (phase composition, structure and particle size of the samples) and morphology have been investigated by means of X-ray diffraction and Scanning electron microscopy. The ZnO powders annealed at 100 °C show highest photocatalytic efficiency and rate constant of dye degradation, which is due to the smaller size of nanocrystallites and their better developed surface. The degradation rate of Acetaminophen and Chloramphenicol increases with time of mechanical activation up to 30 min and then decreases. The optimal temperature and time of mechanoactivation are experimentally established.
authors.affiliation: Laboratory of Nanoparticle Science and Technology, Department of General and Inorganic Chemistry, Faculty of Chemistry and Pharmacy, University of Sofia, 1164, Sofia, Bulgaria. nhnk@chem.uni-sofia.bg.
authors.forename: Nina
authors.initials: N
authors.lastname: Kaneva
authors.affiliation: Laboratory of Nanoparticle Science and Technology, Department of General and Inorganic Chemistry, Faculty of Chemistry and Pharmacy, University of Sofia, 1164, Sofia, Bulgaria.
authors.forename: Assya
authors.initials: A
authors.lastname: Bojinova
authors.affiliation: Laboratory of Nanoparticle Science and Technology, Department of General and Inorganic Chemistry, Faculty of Chemistry and Pharmacy, University of Sofia, 1164, Sofia, Bulgaria.
authors.forename: Karolina
authors.initials: K
authors.lastname: Papazova
authors.affiliation: Laboratory of Nanoparticle Science and Technology, Department of General and Inorganic Chemistry, Faculty of Chemistry and Pharmacy, University of Sofia, 1164, Sofia, Bulgaria.
authors.forename: Dimitre
authors.initials: D
authors.lastname: Dimitrov
authors.affiliation: Institute of Catalysis, Bulgarian Academy of Sciences, "Acad. G. Bonchev" St.,Bl.11, 1113, Sofia, Bulgaria.
authors.forename: Katerina
authors.initials: K
authors.lastname: Zaharieva
authors.affiliation: Institute of Catalysis, Bulgarian Academy of Sciences, "Acad. G. Bonchev" St.,Bl.11, 1113, Sofia, Bulgaria.
authors.forename: Zara
authors.initials: Z
authors.lastname: Cherkezova-Zheleva
authors.affiliation: Institute of Catalysis, Bulgarian Academy of Sciences, "Acad. G. Bonchev" St.,Bl.11, 1113, Sofia, Bulgaria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Eliyas
mesh_terms: D002384:Catalysis; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D055668:Photochemical Processes; D013314:Stress, Mechanical; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D015034:Zinc Oxide
keywords: Mechanical milling; Pharmaceutical drugs; Photocatalysis; Thermal activation; ZnO powders