title: Evaluation of sunlight induced structural changes and their effect on the photocatalytic activity of V2O5 for the degradation of phenols.
abstract: Despite knowing the fact that vanadium pentoxide is slightly soluble in aqueous medium, its photocatalytic activity was evaluated for the degradation of phenol and its derivatives (2-hydroxyphenol, 2-chlorophenol, 2-aminophenol and 2-nitrophenol) in natural sunlight exposure. The prime objective of the study was to differentiate between the homogeneous and heterogeneous photocatalysis incurred by dissolved and undissolved V2O5 in natural sunlight exposure. V2O5 was synthesized by chemical precipitation procedure using Triton X-100 as morphology mediator and characterized by DRS, PLS, Raman, FESEM and XRD. A lower solubility of ∼ 5% per 100ml of water at 23 °C was observed after calcination at 600 °C. The study revealed no contribution of the dissolved V2O5 in the photocatalytic process. In sunlight exposure, V2O5 powder exhibited substantial activity for the degradation, however, a low mineralization of phenolic substrates was observed. The initial low activity of V2O5 followed by a sharp increase both in degradation and mineralization in complete spectrum sunlight exposure, was further investigated that revealed the decrease in the bandgap and the reduction in the particle size with the interaction of UV photons (<420 nm) as this effect was not observable in the exposure of visible region of sunlight. The role of the chemically different substituents attached to an aromatic ring at 2-positions and the secondary interaction of released ions during the degradation process with the reactive oxygen species (ROS) was also explored.
authors.affiliation: Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589, Saudi Arabia.
authors.forename: M
authors.initials: M
authors.lastname: Aslam
authors.affiliation: Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589, Saudi Arabia; Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
authors.forename: Iqbal M I
authors.initials: IM
authors.lastname: Ismail
authors.affiliation: Centre of Nanotechnology, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
authors.forename: Numan
authors.initials: N
authors.lastname: Salah
authors.affiliation: Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589, Saudi Arabia.
authors.forename: S
authors.initials: S
authors.lastname: Chandrasekaran
authors.affiliation: Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589, Saudi Arabia; Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
authors.forename: M Tariq
authors.initials: MT
authors.lastname: Qamar
authors.affiliation: Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589, Saudi Arabia; National Centre for Physics, Quaid-e-Azam University, Islamabad 44000, Pakistan. Electronic address: afmuhammad@kau.edu.sa.
authors.forename: A
authors.initials: A
authors.lastname: Hameed
mesh_terms: D000627:Aminophenols / Q000032:analysis; D002384:Catalysis; D002396:Catechols / Q000032:analysis; D002733:Chlorophenols / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D004563:Electrochemistry / Q000379:methods; D004583:Electrons; D006863:Hydrogen-Ion Concentration; D007477:Ions; D008855:Microscopy, Electron, Scanning; D009596:Nitrophenols / Q000032:analysis; D010316:Particle Size; D019800:Phenol / Q000032:analysis* / Q000737:chemistry; D010777:Photochemistry / Q000379:methods*; D017785:Photons; D017382:Reactive Oxygen Species; D012666:Semiconductors; D012995:Solubility; D013056:Spectrophotometry, Ultraviolet; D013472:Sunlight; D017968:Vanadium Compounds / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D000627:Aminophenols; D002396:Catechols; D002733:Chlorophenols; D007477:Ions; D009596:Nitrophenols; D017382:Reactive Oxygen Species; D017968:Vanadium Compounds; C027667:2-aminophenol; D019800:Phenol; C045573:2-nitrophenol; C066075:vanadium pentoxide; C030683:2-chlorophenol; C034221:catechol
keywords: 2-Aminophenol; 2-Chlorophenol; 2-Hydroxyphenol; 2-Nitrophenol; Phenol; Sunlight; V(2)O(5)