This project addresses the urgent need for efficient removal of antibiotics and textile dyes from water, pollutants that resist conventional treatment and contribute to antimicrobial resistance. Surface modified (multimetallic) zeolitic imidazolate frameworks (ZIFs) are promising candidates for photocatalytic removal of various organic waste, yet major knowledge gaps persist: trimetallic systems remain unexplored, ligand engineering is underutilized, bulk and surface modifications have never been combined and atomic-level structural validation is lacking. The project will develop two libraries of materials: monometallic ZIFs based on four imidazolate linkers, and trimetallic Zn–Co–M (M = Cu, Mn, Fe) ZIFs with engineered metal nodes. Both will be functionalized with conjugated organic molecules to tune light absorption and charge separation. Using an integrated methodology, SCXRD and especially 3D electron diffraction will provide single-crystal data from nanocrystals as small as 50 nm, enabling precise structure solution of novel compositions, while PXRD, BET, ICP-OES, DRS UV-Vis, and EIS will be used for phase purity, porosity, composition, band gap, and charge transfer characterization. Photocatalytic performance toward antibiotics and dyes under visible light will be systematically evaluated, including recycling stability and radical trapping studies. All structural, electronic, and functional descriptors will be merged into a hierarchical structure–property map, from which quantitative design rules will be extracted. An optimal ZIF composition not originally synthesized will be predicted and experimentally validated. The project will generate the first atomic-resolution structures of trimetallic, surface-modified ZIFs, establish rational design principles for next-generation photocatalysts, and contribute to mitigating water pollution and antimicrobial resistance.
The ultimate objective of this project is, therefore, to develop a new class of trimetallic ZIFs with engineered metal nodes and a library of monometallic ZIFs with so far underexplored imidazolate linkers, both combined with conjugated organic molecule surface functionalization, and to derive atomic-level structure-property relationships that enable their use as integrated adsorption-photocatalysis systems for efficient removal of organic pollutants from water.
We the basic objective in mind, we have defined five specific scientific objectives of this project as follows:
- To synthesize and structurally characterize two ZIF phase-pure compound libraries: monometallic ZIFs (M = Zn, Co, Cu, Mn, Fe) employing four unexplored imidazolate linkers and trimetallic Zn-Co-M ZIFs (M = Cu, Mn, Fe) using the standard 2-mIm linker (pristine sets);
- To synthesize and structurally validate surface-modified phase-pure mono- and trimetallic ZIFs;
- To quantify photoelectronic properties of pristine phase-pure mono- and trimetallic ZIFs and their surface-modified analogues;
- To assess the efficiency of pristine ZIFs and their surface-modified composites in removal of two types of pollutants (antibiotics and textile dyes) under visible light irradiation, and
- To extract design rules, and experimentally validate one predicted optimal composition not originally synthesized.