Enhanced Photocatalytic Performance of Nanosized Mixed-Ligand Metal–Organic Frameworks through Sequential Energy and Electron Transfer Process

Abstract

Effective sequestration of harmful organic pollutants from wastewater has been a persistent concern in the interest of environmental and ecological protection from pollution and hazards. Currently, common water treatment technologies such as adsorption, coagulation, and membranes are expensive and not greatly effective. A new class of organic and inorganic composite metal–organic frameworks (MOFs) has emerged as an essential class of materials for numerous applications, including photocatalytic degradation of organic pollutants. Herein, we present a nanosize mixed-ligand MOF (nMLM) which was successfully synthesized by reacting a Zr metal source with a mixture of pyrene and porphyrin building units and further utilized as photocatalyst in the photodegradation of rhodamine B (RhB). The nMLM MOF showed excellent photocatalytic efficiency, which was due to the complementary absorption and sequential energy and electron transfer properties of its building blocks, pyrene and porphyrin. We also propose herein a possible mechanism of the photocatalytic function of the material.

Applications of Metal‐Organic Frameworks in Water Treatment: A Review

“…The abovementioned mixed-ligand MOFs exhibited exceptional working efficiency and wide light absorption coverage ability in the photodegradation process of rhodamine B (RhB). [54] In a recent study, Jeyaseelan et al selected low-cost fumaric acid with abundant active sites as the organic linking agent to prepare three kinds of metal fumaric acid-based MOFs including Zr@ Fu, La@Fu, and Fe@Fu MOF, via the autoclave hydrothermal method, to be used for rapid fluoride removal (Figure 3c). [55] The three synthesized materials all showed outstanding defluorination ability of 4920, 4925, and 4845 mgFˉ Kg -1 , respectively.…”

“…c) Reproduced with permission. [54] Copyright 2020, American Chemical Society. d,e) Reproduced with permission.…”

“…Considering that pyrene-based ligand for NU-1000 and porphyrin-based ligand for PCN-222 were relatively complemented in preponderance, Kim et al synthesized a nanosized mixedligand MOF (nMLM) for photocatalytic degradation of RhB. [54] The result showed that nMLM was more efficient than nPCN-222 and nNU-1000 in photocatalytic test. The superb efficiency of nMLM was traceable to the synergistic reaction of NU-1000 and PCN-222 ligands.…”

“…Copyright 2020, Royal Society of Chemistry. b) Reproduced with permission [54]. Copyright 2020, American Chemical Society.…”

Multi‐Component Metal‐Organic Frameworks Significantly Boost Visible‐Light‐Driven Hydrogen Production Coupled with Selective Organic Oxidation

“…The diversity of the building blocks of orderly frameworks can afford high‐density photoactive sites allowing the organic ligands being linked together and well isolated by the metal ions, meanwhile avoiding the self‐quenching of high‐density ligands to increase the light harvest ability [16–18] . As MOFs can be synthesized via a multivariate (MTV) strategy, [19–23] different photoactivity ligands within one single MOF can afford a multifunctional heterogeneous photocatalyst, [24–29] which could fully reflect the advantages of two types of ligands. Herein, the combination of multiple components within a single MOF [30] was a powerful way to achieve efficient conversion of photocatalytic hydrogen production coupled with selective oxidation of amines.…”