A template-free, sonochemical route to porous ZnO nano-disks

Sayan Bhattacharyya, A. Gedanken

Research output: Contribution to journalArticlepeer-review

126 Scopus citations

Abstract

A template-free, sonochemical aqueous route was used to synthesize hexagonal-shaped ZnO nanocrystals with a combined micro- and mesoporous structure. The products are much more porous when the sonohydrolysis is carried out under argon than their sonication under air. This has been attributed to the higher average specific heat ratio γ (=Cp/Cv) of argon gas, leading to higher bubble collapse temperatures. Small-angle XRD (SAXRD) studies show that the microporosity is lost at 250 °C, while the mesoporous structure persists till a very high temperature (550 °C). The BET surface area of the products synthesized under argon and air are 35 and 13 m2/g, respectively. The pore size is distributed from 1 nm (micropore) to 3.1-3.4 nm (mesopore), while the ZnO nanoparticles are 6.3 ± 1.2 nm. The possible mechanisms of the self-assembled pore formation are attributed to the organic porous framework of basic zinc acetate. The excitonic absorption of the ZnO occurs at 349 nm. The photoluminescence (PL) spectra of the ZnO nano-disks show the red-shifted band edge exciton transitions and the presence of deep levels due to oxygen vacancies or surface-deep traps, because of the porous structure.

Original languageEnglish
Pages (from-to)553-559
Number of pages7
JournalMicroporous and Mesoporous Materials
Volume110
Issue number2-3
DOIs
StatePublished - 15 Apr 2008

Bibliographical note

Funding Information:
This research was supported by an EC grant to the LIDWINE Consortium through Contract No. NMP2-CT-2006-026741 of the 6th EC Program.

Funding

This research was supported by an EC grant to the LIDWINE Consortium through Contract No. NMP2-CT-2006-026741 of the 6th EC Program.

FundersFunder number
6th EC
European CommissionNMP2-CT-2006-026741

    Keywords

    • Photoluminescence
    • Porous
    • Sonochemistry
    • Template-free
    • Zinc oxide

    Fingerprint

    Dive into the research topics of 'A template-free, sonochemical route to porous ZnO nano-disks'. Together they form a unique fingerprint.

    Cite this