Abstract
The United States Environmental Protection Agency (EPA) recognizes atrazine, a commonly used herbicide, as an endocrine disrupting compound. Excessive use of this agrochemical results in contamination of surface and ground water supplies via agricultural runoff. Efficient removal of atrazine from contaminated water supplies is paramount. Here, the mechanism governing atrazine adsorption in Zr6-based metal−organic frameworks (MOFs) has been thoroughly investigated by studying the effects of MOF linkers and topology on atrazine uptake capacity and uptake kinetics. We found that the mesopores of NU-1000 facilitated rapid atrazine uptake saturating in <5 min and that the pyrene-based linkers offered sufficient sites for π−π interactions with atrazine as demonstrated by the near 100% uptake. Without the presence of a pyrene-based linker, NU-1008, a MOF similar to NU-1000 with respect to surface area and pore size, removed <20% of the exposed atrazine. These results suggest that the atrazine uptake capacity demonstrated by NU-1000 stems from the presence of a pyrene core in the MOF linker, affirming that π−π stacking is responsible for driving atrazine adsorption. Furthermore, NU-1000 displays an exceptional atrazine removal capacity through three cycles of adsorption−desorption. Powder X-ray diffraction and Brunauer−Emmett− Teller surface area analysis confirmed the retention of MOF crystallinity and porosity throughout the adsorption−desorption cycles.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 6097-6103 |
| Number of pages | 7 |
| Journal | ACS Applied Materials and Interfaces |
| Volume | 11 |
| Issue number | 6 |
| DOIs | |
| State | Published - Feb 13 2019 |
Funding
O.K.F. gratefully acknowledges the support of the Nanoporous Materials Genome Center, funded by the U.S. DOE, Office of Science, Basic Energy Sciences Program (award DE-FG02-17ER16362). R.J.D. appreciates the support of the Northwestern University Ryan Fellowship granted by the International Institute of Nanotechnology and The Graduate School. This work made use of the EPIC, Keck-II, and SPID facilities of Northwestern University\u2019s NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205); the MRSEC program (NSF DMR-1121262) at the Materials Research Science and Engineering Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN. O.K.F. gratefully acknowledges the support of the Nanoporous Materials Genome Center, funded by the U.S. DOE, Office of Science, Basic Energy Sciences Program (award DE-FG02-17ER16362). R.J.D. appreciates the support of the North-western University Ryan Fellowship granted by the International Institute of Nanotechnology and The Graduate School. This work made use of the EPIC, Keck-II, and SPID facilities of Northwestern University\u2019s NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205); the MRSEC program (NSF DMR-1121262) at the Materials Research Science and Engineering Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN.
Keywords
- adsorption
- adsorption mechanism
- atrazine
- metal−organic frameworks
- π−π interactions
ASJC Scopus subject areas
- General Materials Science
