Iron Based Metal Organic Frameworks as Photocatalysts for Chromium (VI) Degradation

Abstract

The photocatalytic reduction of Cr(VI) is investigated over iron(III) based metal-organic frameworks (MOFs) with the structures NH2-MIL-88B(Fe) and NH2-MIL-101(Fe). The only parameter which leads to a different structure is the molar ratio of metal to ligand. If the molar ratio is the same, the structure NH2-MIL-88B(Fe) is formed, whereas if the molar ratio is different, the structure NH2-MIL-101(Fe) is formed. Although the photocatalysts have different structures, they are both able to reduce Cr(VI) dye under visible light irradiation. NH2-MIL-101(Fe) has a higher efficiency compared to NH2-MIL-88B(Fe), which is likely attributed to the MOF’s higher crystallinity and different structure. Additionally, a higher metal to ligand ratio in the NH2-MIL-101(Fe) photocatalyst leads to the highest efficiency compared to other NH2-MIL-101(Fe) photocatalysts. NH2-MIL-101(Fe) can be used as an efficient photocatalyst for the degradation of the toxic heavy metal, Cr(VI). This finding can ultimately lead to the development of a novel and effective method for wastewater treatment.