Visible-light-induced heterostructured Zn-Al-In mixed metal oxide nanocomposite photocatalysts derived from a single precursor

The present work reported the synthesis of visible-light-induced heterostructured Zn-Al-In mixed metal oxide (ZnAlIn-MMO) nanocomposite photocatalysts derived from Zn-Al-In layered double hydroxide precursors. The structural and optical properties of the novel nanomaterials were characterized by powder X-ray diffraction (XRD), Al-27 solid-state nuclear magnetic resonance (NMR), transmission electron microscopy (TEM), low temperature nitrogen adsorption-desorption experiments and UV-vis diffuse reflectance spectroscopy. The results reveal that the well-dispersed amorphous In2O3 domains can be intimately attached to ZnO nanocrystallites in the ZnAlIn-MMO nanocomposites, thus forming the heterostructure of mixed metal oxides, and that the band gaps of ZnAlIn-MMO nanomaterials are in the range of 2.50-2.60 eV, indicative of visible light absorption characteristic. Compared to single-phase In2O3 sample, ZnAlIn-MMO nanocomposites exhibited enhanced photocatalytic activity towards the degradation of methylene blue under visible light irradiation. Especially, ZnAlIn-MMO with the Zn/Al/In molar ratio of 6:1:1 had the highest photocatalytic activity, which was attributable to the efficient separation and transportation of photogenerated charge carriers originating from the novel heterostructure and large specific surface area of such nanocomposite. The present finding provides an approach to fabricate new types of visible-light-induced heteronanostructured photocatalysts. (C) 2011 Elsevier B.V. All rights reserved.