Study on the Stability, Evolution of Physicochemical Properties, and Postsynthesis of Metal-Organic Frameworks in Bubbled Aqueous Ozone Solution

Caiyi Yue; Lei Wu; Yaqian Lin; Yuqi Lu; Chao Shang; Rui Ma; Xiangcheng Zhang; Xiaoning Wang; Winston Duo Wu; Xiao Dong Chen; Zhangxiong Wu

doi:10.1021/acsami.1c02213

Study on the Stability, Evolution of Physicochemical Properties, and Postsynthesis of Metal-Organic Frameworks in Bubbled Aqueous Ozone Solution

ACS Appl Mater Interfaces. 2021 Jun 9;13(22):26264-26277. doi: 10.1021/acsami.1c02213. Epub 2021 May 26.

Authors

Affiliation

¹ Particle Engineering Laboratory, School of Chemical and Environmental Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou City, Jiangsu 215123, P. R. China.

PMID: 34038089
DOI: 10.1021/acsami.1c02213

Abstract

Metal-organic frameworks (MOFs) are highly promising in many areas. Their application and postsynthesis under strong oxidative environments are emerging. However, the stability, physicochemical property evolution, and possible postmodification and postsynthesis of MOFs in strong oxidative solutions are largely unknown. In this paper, the behaviors of a series of MOFs in bubbled aqueous ozone (O₃) solutions are studied. The chosen MOFs are categorized into trimesic type including MIL-101(Fe) and MIL-96(Al); terephthalic type including MOF-74(Co), UiO-66(Zr), MIL-53(Al), and MIL-101(Cr); and imidazole type including ZIF-67(Co) and ZIF-8(Zn), based on the ligand structure. The intrinsic stability and evolution of the physicochemical properties of these MOFs during aqueous O₃ treatment are elucidated using structural, morphological, textural, thermal, and spectroscopic analyses. Several stable, metastable, and instable MOFs are identified. The critical parameters that determine the stability and capability for postsynthesis of these MOFs in aqueous O₃ solutions are discussed. The stability follows the general order of trimesic-type > terephthalic-type ≫ imidazole-type MOFs because of the distinct antioxidation capability of the ligands. The effects of the ligand, metal cation, and their coordination number on stability are discussed. MIL-100(Fe), MIL-96(Al), and MOF-74(Co) are stable in aqueous O₃. UiO-66(Zr), MIL-53(Al), and MIL-101(Cr) are metastable that their porosity, particle size, and crystallinity can be postmodified. ZIF-67(Co) and ZIF-8(Zn) are instable and can be gradually and completely disassembled. Their particle size and morphology and surface groups can be tuned by controlling the treatment time. Postsynthesis of metal hydroxides from ZIF-67(Co) and gradual release of dissolved zinc ion from ZIF-8(Zn) are achievable. The stable MIL-96(Al) shows promising performance in catalytic ozonation for degrading 4-nitrophenol, and the α-Co(OH)₂ derived from treating ZIF-67(Co) shows highly promising performance in the electrocatalytic oxygen evolution reaction (OER).

Keywords: MOFs; ozone oxidation; postsynthesis; stability; structure evolution.