title: Enhanced photocatalytic performances of hierarchical ZnO/ZnAl2O4 microsphere derived from layered double hydroxide precursor spray-dried microsphere.
abstract: Layered double hydroxides (LDHs), also called hydrotalcites, have been widely investigated for degradation of dye molecules, in the forms of direct photocatalysts, supports or precursors to ZnO-containing photocatalysts. LDH precursor-derived ZnO/ZnAl2O4 photocatalytic nanostructures have hitherto been created, involving ZnO/ZnAl2O4 powder and templated hierarchical frameworks with laboratory-scale preparations. We herein report a scalable preparation of ZnO/ZnAl2O4 microsphere derived from ZnAl-LDH precursor spray-dried microsphere. Survey of textural properties shows that ZnO/ZnAl2O4 microspheres maintain the hierarchically spherical feature and the relatively large surface area. Photocatalytic evaluation under UV irradiation shows that the ZnO/ZnAl2O4 microspheres exhibit highly enhanced photodegradation performance to methylene blue (MB) in comparison with the commercial ZnO powder. A preferential photodegradation to methyl orange (MO) of the MO/MB mixture was also observed, which was illustrated experimentally in terms of the favorable interaction and distribution between basic MO molecules and the acidic-site ZnO/ZnAl2O4 photocatalyst. Our results may initiate large-scale production of microspheres with promising photocatalytic performances.
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
authors.forename: Ruijie
authors.initials: R
authors.lastname: Huo
authors.forename: Ye
authors.initials: Y
authors.lastname: Kuang
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Zhao
authors.forename: Fazhi
authors.initials: F
authors.lastname: Zhang
authors.forename: Sailong
authors.initials: S
authors.lastname: Xu
keywords: Calcination; Layered double hydroxide precursor; Preferential photodegradation; Spray-dried microsphere; ZnO/ZnAl(2)O(4) photocatalyst