Enhancement of photocatalytic activity of Cu-doped ZnO nanorods for the degradation of an insecticide: Kinetics and reaction pathways.
The photocatalytic degradation of organophosphorus pesticide such as diazinon was investigated by Cu-doped ZnO nanorods. Cu-doped ZnO nanorods were synthesized via a facile co-precipitation method. The catalyst was characterized by XRD, FESEM, EDX, VSM, XPS, and pHzpctechniques. The effects of some operational parameters such as solution pH, Cu-doped ZnO nanorods dosage, initial diazinon concentration, oxygen and nitrogen gases, H2O2concentration, and type of organic compounds on the degradation efficiency were discussed through the photocatalytic experiments using the Cu-doped ZnO nanorods. Neutral pH was selected as an optimal pH condition due to a photo-corrosion of ZnO in acidic and basic conditions. As the Cu-doped ZnO nanorods dosage increased up to 0.2 g/L, degradation efficiency of diazinon was continuously enhanced. Pseudo-first-order rate constant (kobs) was decreased from 0.051 to 0.0052 min-1and electrical energy per order (EEo) was increased from 94.12 to 923.08 (kWh/m3) by increasing diazinon concentration from 10 to 50 mg/L, respectively. The efficiency of the UV/Cu-doped ZnO for diazinon removal was approximately 96.97%, which was more effective than the UV/ZnO process (58.52%). Photocatalytic activity was maintained even after five successive cycles.
Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.
Mehdi
M
Shirzad-Siboni
Research Center for Environmental Health Technology, Iran University of Medical Sciences, Iran; Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.
Ahmad
A
Jonidi-Jafari
Research Center for Environmental Health Technology, Iran University of Medical Sciences, Iran; Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.
Mahdi
M
Farzadkia
Research Center for Environmental Health Technology, Iran University of Medical Sciences, Iran; Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.
Ali
A
Esrafili
Research Center for Environmental Health Technology, Iran University of Medical Sciences, Iran; Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran. Electronic address: gholamim@iums.ac.ir.
Mitra
M
Gholami
D002384:Catalysis; D011232:Chemical Precipitation; D003300:Copper / Q000737:chemistry*; D003976:Diazinon / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007306:Insecticides / Q000737:chemistry; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D043942:Nanotubes / Q000737:chemistry*; D055668:Photochemical Processes; D056951:Photoelectron Spectroscopy; D012996:Solutions / Q000737:chemistry; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000737:chemistry*
D007306:Insecticides; D012996:Solutions; D003300:Copper; D006861:Hydrogen Peroxide; D015034:Zinc Oxide; D003976:Diazinon
Cu; Diazinon; Hybridization; Nanoparticles; Photocatalyst; ZnO