MOF-derived nanocrystalline ZnO with controlled orientation and photocatalytic activity

Esmail Doustkhah; Mohamed Esmat; Naoki Fukata; Yusuke Ide; Dorian A H Hanaor; M Hussein N Assadi

doi:10.1016/j.chemosphere.2022.134932

MOF-derived nanocrystalline ZnO with controlled orientation and photocatalytic activity

Chemosphere. 2022 Sep;303(Pt 1):134932. doi: 10.1016/j.chemosphere.2022.134932. Epub 2022 May 11.

Authors

Esmail Doustkhah¹, Mohamed Esmat², Naoki Fukata³, Yusuke Ide³, Dorian A H Hanaor⁴, M Hussein N Assadi⁵

Affiliations

¹ Koç University Tüpraş Energy Center (KUTEM), Department of Chemistry, Koç University, 34450, Istanbul, Turkey; International Center for Materials Nanoarchitechtonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Ibaraki, Japan. Electronic address: esmaildostkhah@gmail.com.
² International Center for Materials Nanoarchitechtonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Ibaraki, Japan; Materials Science and Nanotechnology Department, Faculty of Postgraduate Studies for Advanced Sciences (PSAS), Beni-Suef University (BSU), Beni-Suef, 62511, Egypt.
³ International Center for Materials Nanoarchitechtonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Ibaraki, Japan.
⁴ Technische Universität Berlin, Faculty III Process Sciences, Institute of Material Science and Technology, Chair of Advanced Ceramic Materials, Straße des 17. Juni 135, 10623, Berlin, Germany.
⁵ RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.

PMID: 35568217
DOI: 10.1016/j.chemosphere.2022.134932

Abstract

We show here that MOF-5, a sample Zn-based MOF, can uniquely transform into distinct zinc oxide nanostructures. Inspired by the interconversion synthesis of zeolites, we converted MOF-5 into nanocrystalline ZnO. We found the conversion of MOF-5 into ZnO to be tunable and straightforward simply by controlling the treatment temperature and choosing an appropriate structure-directing agent (SDA). Refined X-ray diffraction (XRD) patterns showed that a synthesis temperature of 180 °C (sample ZnO-180) was optimal for achieving high crystallinity. We examined ZnO-180 with high-resolution transmission electron microscopy (HRTEM), which confirmed that the samples were made of individual crystallites grown along the c-axis, or the (001) direction, thus exposing lower energy surfaces and corroborating the XRD pattern and the molecular dynamics calculations. Further investigations revealed that the obtained ZnO at 180 °C has a superior photocatalytic activity in degrading methylene blue to other ZnO nanostructures obtained at lower temperatures.

Keywords: Crystal planes; Metal-organic framework; Nanoarchitecture control; Photocatalytic degradation; Single-crystal ZnO.