title: Characterization and improved solar light activity of vanadium doped TiO2/diatomite hybrid catalysts.
abstract: V-doped TiO2/diatomite composite photocatalysts with different vanadium concentrations were synthesized by a modified sol-gel method. The diatomite was responsible for the well dispersion of TiO2 nanoparticles on the matrix and consequently inhibited the agglomeration. V-TiO2/diatomite hybrids showed red shift in TiO2 absorption edge with enhanced absorption intensity. Most importantly, the dopant energy levels were formed in the TiO2 bandgap due to V(4+) ions substituted to Ti(4+) sites. The 0.5% V-TiO2/diatomite photocatalyst displayed narrower bandgap (2.95 eV) compared to undoped sample (3.13 eV) and other doped samples (3.05 eV) with higher doping concentration. The photocatalytic activities of V doped TiO2/diatomite samples for the degradation of Rhodamine B under stimulated solar light illumination were significantly improved compared with the undoped sample. In our case, V(4+) ions incorporated in TiO2 lattice were responsible for increased visible-light absorption and electron transfer to oxygen molecules adsorbed on the surface of TiO2 to produce superoxide radicals ˙O2(-), while V(5+) species presented on the surface of TiO2 particles in the form of V2O5 contributed to e(-)-h(+) separation. In addition, due to the combination of diatomite as support, this hybrid photocatalyst could be separated from solution quickly by natural settlement and exhibited good reusability.
authors.affiliation: School of Chemical and Environmental Engineering, China University of Mining & Technology, Beijing 100083, PR China; School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia. Electronic address: b.wang6@uq.edu.au.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.affiliation: School of Chemical and Environmental Engineering, China University of Mining & Technology, Beijing 100083, PR China. Electronic address: z111@163.com.
authors.forename: Guangxin
authors.initials: G
authors.lastname: Zhang
authors.affiliation: School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia. Electronic address: xue.leng@uq.net.au.
authors.forename: Xue
authors.initials: X
authors.lastname: Leng
authors.affiliation: School of Chemical and Environmental Engineering, China University of Mining & Technology, Beijing 100083, PR China. Electronic address: zhiming.baxia@163.com.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Sun
authors.affiliation: School of Chemical and Environmental Engineering, China University of Mining & Technology, Beijing 100083, PR China. Electronic address: shuilinzheng8@gmail.com.
authors.forename: Shuilin
authors.initials: S
authors.lastname: Zheng
mesh_terms: D000327:Adsorption; D002384:Catalysis; D004396:Coloring Agents / Q000737:chemistry; D007692:Diatomaceous Earth / Q000737:chemistry / Q000528:radiation effects; D010782:Photolysis; D059027:Recycling; D012235:Rhodamines / Q000737:chemistry; D013472:Sunlight; D014025:Titanium / Q000737:chemistry / Q000528:radiation effects; D014639:Vanadium / Q000737:chemistry / Q000528:radiation effects; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification
chemical_list: D004396:Coloring Agents; D012235:Rhodamines; D014874:Water Pollutants, Chemical; D014639:Vanadium; C009495:titanium dioxide; D007692:Diatomaceous Earth; C033787:diatomite; D014025:Titanium; C029773:rhodamine B
keywords: Diatomite; Doping TiO(2); Photocatalytic degradation; Sol–gel method