Hot-Pressing Method To Prepare Imidazole-Based Zn(II) Metal–Organic Complexes Coatings for Highly Efficient Air Filtration

Particulate
matters (PMs) air pollution has become a serious environmental
issue due to its great threat to human health. Herein, metal–organic
complexes PBM-Zn1 and PBM-Zn2 coatings (noted as PBM-Zn-Filter) have
been produced by the hot-pressing method on various substrates for
the first time. Layer-by-layer PBM-Zn-Filters were also obtained through
varying hot-pressing cycles. The obtained PBM-Zn-Filters with high
robustness show excellent performance in PMs removal. In particular,
benefiting from thelarger conjugation system, micropore structure,
lower pressure drop, higher electrostatic potential ζ, and electron
cloud exposed metal center of PBM-Zn2 (DFT calculations), PBM-Zn2@melamine
foam-4 gives the highest removal rates, PM2.5:99.5% ± 1.2% and
PM10:99.3% ± 1.1%, and the removal efficiency for capture PM2.5
and PM10 particles in cigarette smoke were both retained at high levels
(>95.5%) after 24 h tests. More importantly, a homemade mask is
made
up by imbedding the PBM-Zn2@melamine foam-4 into a commercial breathing
mask, which shows higher removal efficiency, lower pressure drop,
smaller thickness, and higher quality factor than two commercial breathing
masks, the PMs removal efficiencies for both PM2.5 and PM10 are 99.6%
± 0.5% and 99.4% ± 0.8%, and acceptable air resistance are
demonstrated.