title: The layered double hydroxide route to Bi-Zn co-doped TiO₂ with high photocatalytic activity under visible light.
abstract: In this work, a co-doped Bi-Zn-TiO₂ photocatalist is synthesized by an original synthesis route of layered double hydroxide followed by heat treatment at 670 °C. After characterization the photocatalyst efficiency is estimated by the photo-discoloration of an anionic dye (indigo carmine) under visible light and compare to TiO₂-P25 as reference material. In this new photocatalyst, anatase and ZnO wurtzite are the only identified crystalline phase, rutile and Bi₂O₃ being undetected. Moreover, the binding energy of Bi determined (XPS analysis) is different from the one of Bi in Bi₂O₃. Compared to TiO₂-P25, the absorption is red shifted (UV-vis DRS) and the Bi-Zn-TiO₂ photocatalyst showed sorption capacity toward indigo carmine higher than that TiO₂-P25. The kinetics of the photo-discoloration is faster with Bi-Zn-TiO₂ than with TiO₂-P25. Indeed, a complete discoloration is obtained after 70 min and 120 min in the presence of Bi-Zn-TiO₂ and TiO₂-P25 respectively. The identification of the responsible species on photo-discoloration was carried out in the presence of different scavengers. The study showed that the first responsible is h(+) specie with a moderate contribution of superoxide anion radical and a minor contribution of the hydroxyl radical. The material showed high stability after five uses with the same rate of photo-discoloration.
authors.affiliation: Laboratoire de Valorisation des Matériaux, Université de Mostaganem BP 227, Mostaganem 27000 Algeria.
authors.forename: Bahia
authors.initials: B
authors.lastname: Benalioua
authors.affiliation: Laboratoire de Valorisation des Matériaux, Université de Mostaganem BP 227, Mostaganem 27000 Algeria.
authors.forename: Meriem
authors.initials: M
authors.lastname: Mansour
authors.affiliation: Laboratoire de Valorisation des Matériaux, Université de Mostaganem BP 227, Mostaganem 27000 Algeria. Electronic address: bentouami@gmail.com.
authors.forename: Abdelhadi
authors.initials: A
authors.lastname: Bentouami
authors.affiliation: ICG-CMOS-UMR 5253, Université Montpellier 2, Place Eugène Bataillon CC 1702, 34095 Montpellier Cedex 05, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Boury
authors.affiliation: Laboratoire de Valorisation des Matériaux, Université de Mostaganem BP 227, Mostaganem 27000 Algeria.
authors.forename: El Hadj
authors.initials: el H
authors.lastname: Elandaloussi
mesh_terms: D001729:Bismuth / Q000737:chemistry*; D002384:Catalysis; D004396:Coloring Agents; D017743:Equipment Reuse; D006878:Hydroxides / Q000737:chemistry*; D007203:Indigo Carmine / Q000737:chemistry; D008027:Light; D010777:Photochemistry; D013056:Spectrophotometry, Ultraviolet; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
chemical_list: D004396:Coloring Agents; D006878:Hydroxides; C009495:titanium dioxide; D014025:Titanium; D007203:Indigo Carmine; D015032:Zinc; D001729:Bismuth
keywords: Bi–Zn–TiO(2); Indigo Carmine; LDH; Photocatalyst; Visible Light