Hydrothermal synthesis and humidity sensing property of ZnO nanostructures and ZnO-In(OH)3 nanocomposites

Edit Pál; Viktória Hornok; Robert Kun; Albert Oszkó; Torben Seemann; Imre Dékány; Matthias Busse

doi:10.1016/j.jcis.2012.04.050

Hydrothermal synthesis and humidity sensing property of ZnO nanostructures and ZnO-In(OH)3 nanocomposites

J Colloid Interface Sci. 2012 Jul 15;378(1):100-9. doi: 10.1016/j.jcis.2012.04.050. Epub 2012 Apr 26.

Authors

Edit Pál¹, Viktória Hornok, Robert Kun, Albert Oszkó, Torben Seemann, Imre Dékány, Matthias Busse

Affiliation

¹ University of Bremen, Faculty of Production Engineering, Bremen, Germany. edit.pal@uni-bremen.de

PMID: 22587905
DOI: 10.1016/j.jcis.2012.04.050

Abstract

Prism- and raspberry-like ZnO nanoparticles and ZnO-In(OH)(3) nanocomposites were prepared by template free hydrothermal method. XRD investigations and microscopic studies showed that pill-like In(OH)(3) particles with body-centered cubic crystal structure formed on the surface of ZnO nanoparticles resulting in increased specific surface area. TEM-EDX mapping images demonstrated that not only nanocomposite formation took place in the course of the synthesis, but zinc ions were also built into the crystal lattice of the In(OH)(3). However, only undoped In(OH)(3) was found on the surface of the pill-like particle aggregates by XPS analyses. The raspberry- and prism-like ZnO particles exhibit strong visible emission with a maximum at 585 and 595 nm, respectively, whose intensity significantly increase due to nanocomposite formation. Photoelectric investigations revealed that photocurrent intensity decreased with increasing indium ion concentration during UV light excitation, which was explained by increase in visible fluorescence emission. QCM measurements showed that morphology of ZnO and concentration of In(OH)(3) had an influence on the water vapor sensing properties.