(410c) Investigation of the Use of Metal-Organic Frameworks for Combined Water Purification and Catalytic H2 Production

Lately, a few studies have been reported on the use of metal-organic frameworks (MOFs) for water purification via adsorption of contaminants and/or via photocatalytic degradation. MOFs correspond to 3D crystalline nanomaterials networks consisting of metallic clusters connected via organic ligands. They are characterized by their high porosity and hence have been investigated for applications in water purification, especially for the removal of organics from water. It is interesting to notice that in parallel to those studies, recent work has also been devoted to using MOFs to photocatalytically produce H₂ from water and organic molecules. Up until now, organic contaminants adsorptive removal, photodegradation as well as H₂ evolution have been investigated independently of each other. Hence, an opportunity arises to combine water purification and energy generation (in the form of H₂).

In this work, we have focused on the investigation of two specific MOF families (UiO-66(Zr) and MIL-53) and investigated its adsorptive and photocatalytic properties. The UiO-66(Zr) material was synthesized along with its functionalized counterparts (X-UiO-66(Zr), with X = NH₂, NO₂, Br). MIL-53(M) was synthesized with different metals ions (M = Al, Fe and Cr). The materials were characterized by a number of analytical and spectroscopic techniques in order to determine the effects of functionalization on the band gap and conduction band. In addition, the materials were tested for the adsorption and photocatalytic degradation of organics in water and the simultaneous production of H₂. This work reports on the impact of the abovementioned structural and chemical modifications on the MOFâ??s electronic properties and their performance as dual-purpose adsorbent/catalyst for water purification and H₂ production.