Green Full Conversion of ZnO Nanopowders to Well-Dispersed
Zeolitic Imidazolate Framework‑8 (ZIF-8) Nanopowders via a
Stoichiometric Mechanochemical Reaction for Fast Dye Adsorption
posted on 2020-03-11, 15:50authored byMahdiar Taheri, Iolanda Di Bernardo, Adrian Lowe, David R. Nisbet, Takuya Tsuzuki
In recent years,
many nanofabrication methodologies to engineer
metal organic frameworks (MOFs) have been investigated. However, there
is only a small number of studies that explores scalable and environmentally
friendly synthesis routes. This study reports the production of well-dispersed
MOF nanopowders from an inexpensive precursor, in a green and scalable
manner, with a high yield and minimal waste, for water remediation
applications. One-step mechanochemical processing of a stoichiometric
ratio of ZnO nanoparticles and 2-methylimidazole resulted in the full
conversion of ZnO nanopowders into zeolitic imidazolate framework-8
(ZIF-8) of ca. 80 nm in diameter with little agglomeration. The particles
had a surface area of 1885 m2/g, among the highest reported
for ZIF-8 and close to the theoretical maximum of 1947 m2/g. For the first time, we studied the enhanced ability of our converted
nanopowders to adsorb more model organic pollutants than ZIF-8 nanopowders
synthesized via the most commonly used solution-based method. Details
of the processing conditions, including milling-ball size, milling
time, and postmilling treatment that influence the conversion yield,
were systematically investigated using dry reactive grinding and liquid-assisted
grinding. This work provides a new strategy for the commercial production
of wide-ranging MOFs for environmental applications.