Fabrication and photocatalytic properties of novel ZnO/ZnAl₂O₄ nanocomposite with ZnAl₂O₄ dispersed inside ZnO network

Abstract

Abstract Novel ZnO/ZnAl 2 O 4 nanocomposites with ZnAl 2 O 4 nanoparticles homogeneously dispersed inside a network of ZnO are fabricated by thermal treatment of a single‐source precursor of ZnAl‐layered double hydroxides (ZnAl‐LDHs) at 800°C. The effects of the Zn/Al molar ratio of the LDH precursors on the structure, composition, morphology, textural as well as UV‐absorbing properties and photocatalytic activities of the nanocomposites are investigated in detail. The results show that the ZnO/ZnAl 2 O 4 nanocomposites derived from the ZnAl‐LDHs precursors have superior photocatalytic performances to either single phase ZnO or similar ZnO/ZnAl 2 O 4 samples fabricated by chemical coprecipitation or physical mixing method. The heterojunction nanostructure and the strong coupling between the ZnO and ZnAl 2 O 4 phase derived from ZnAl‐LDHs precursors are proposed to contribute the efficient spatial separation between the photo‐generated electrons and holes, which can concomitantly improve the photocatalytic activities. © 2011 American Institute of Chemical Engineers AIChE J, 2012