@article{2928273,
    title = "A Ca2+ MOF combining highly efficient sorption and capability for
voltammetric determination of heavy metal ions in aqueous media",
    author = "Anastasia D. Pournara and Antigoni Margariti and Georgios D. Tarlas and Andreas Kourtelaris and Valeri Petkov and Christos Kokkinos and Anastasios Economou and Giannis S. Papaefstathiou and Manolis J. Manos",
    journal = "Journal of Materials Chemistry A",
    year = "2019",
    volume = "7",
    number = "25",
    pages = "15432--15443",
    publisher = "Royal Society of Chemistry (RSC)",
    issn = "2050-7488, 2050-7496",
    doi = "10.1039/c9ta03337h",
    abstract = "We recently discovered that a Ca2+ two-dimensional framework, namely
[Ca(H4L)(DMA)(2)]center dot 2DMA (Ca-MOF), was capable of exchanging
the Ca2+ ions with Cu2+ almost quantitatively in a matter of seconds in
aqueous solution. Herein, we report that Ca-MOF exhibits the capability
of both removal and voltammetric determination of heavy metal ions in
aqueous media. Ca-MOF shows one of the highest Pb2+ sorption capacities
(similar to 522 mg g(-1)) reported for MOFs. More importantly, a column
filled with Ca-MOF (1% wt) particles dispersed in silica sand (99% wt)
can quantitatively remove traces of Pb2+ (similar to 100 ppb) from a
relatively large volume of a wastewater simulant solution (containing a
large excess of competitive ions). Ca-MOF is also highly efficient for
sorption of Cd2+, Ni2+ and Zn2+, even in the presence of several
competitive cations. Actually, the Cd2+ sorption capacity (similar to
220 mg g(-1)) of Ca-MOF is one of the largest reported for MOFs.
Furthermore, detailed Ni2+ and Zn2+ sorption studies of MOFs have not
been described prior to this work. The mechanism of the M2+ (M2+ = Pb2+,
Cd2+, Ni2+, Zn2+) exchange process was elucidated based on a series of
spectroscopic, analytical and X-ray diffraction methods. In addition, a
simple ready-to-use electrochemical sensor based on modified graphite
paste with Ca-MOF was fabricated and successfully utilized for the
determination of Pb2+, Cd2+, Cu2+ and Zn2+ at mu g L-1 levels in aqueous
solutions by anodic stripping voltammetry (ASV). Overall, this work
demonstrates, for the first time, a dual function of a MOF as a sorbent
and as an electrochemical sensor for heavy metal ions, thus opening a
new window for materials with application in both environmental
remediation and monitoring."
}