Construction of visible‐light‐responsive metal–organic framework with pillared structure for dye degradation and Cr(VI) reduction

Abstract

A water‐stable mixed‐linker metal–organic framework (MOF) was rationally synthesized using a controllable pillared‐layer method. The prepared Co(II)–MOF shows wide‐range absorption in the visible light region due to the incorporation of highly conjugated anthracene‐based bipyridine ligand. Experiments suggest that the MOF is highly efficient for the photoreduction of toxic Cr(VI) ions in water under visible light. Important issues affecting photocatalytic performance, such as the influence of pH and the control of electron–hole separation by scavenger, were carefully examined. Beyond Cr(VI) ions, we also explored the photocatalytic degradation performance of the MOF using a persistent azo dye as a model substrate, where H2O2‐involved advanced oxidation process was applied. Control experiments suggest that the introduction of environmentally benign H2O2 significantly enhances the degradation performance due to the generation of reactive hydroxyl radicals. The study not only demonstrates the great feasibility of the preparation of a new MOF photocatalyst through a controllable pillared‐layer method, but also reveals that rational functionalization of ligand in the MOF is convenient for achieving desirable applications.

Insight into the photocatalytic properties of phosphonate‐based metal–organic frameworks for reduction of Cr (VI) and Synergistic elimination of organic dyes under natural sunlight

“…It is expected that this work could provide a new solar-driven advanced oxidation/reduction processes for water depollution and develops the applicability of metalorganic frameworks in photocatalysis for simultaneously processed different water pollution and chemical synthesis. MIL-53(Fe) 20/1000 SS/40 98 [15] Zn-MOF 20/1000 NS/90 93 [39] UiO-66-NH 2 (Zr) 5/− SS/120 98 [40] NNU-36 10/375 SS/60 95 [41] JLU-MOF60 80/400 SS/70 98 [42] NNU-37 10/625 SS/110 91 [43] STA-12(Fe) 30/250 NS/25 98 This work SS, simulated sunlight; NS, natural sunlight.…”

Recent Progress in the Development of MOF-Based Photocatalysts for the Photoreduction of Cr(VI)

“…A pillar cobalt-based MOF, NNU-37, was prepared via a solvothermal method using a mix of ligands, BPEA (bipyridine ethynyl anthracene) and 4,4′-biphenyldicarboxylate (BPDC), in a mix of solvents, DMF−CH 3 CN−H 2 O (15:5:2 v/v/v). 55 The presence of a highly conjugated anthracene-based bipyridine ligand in the framework effectively extended the absorption edge to the visible region and generated a narrow bandgap of 2.13 eV. By applying the MOF, a ∼92% photoreduction of Cr (VI) was obtained within 110 min under visible light and using methanol as a hole scavenger.…”

Photoactive Hexaazaphenalene‐based Coordination Network as a Two‐Pathway Photosensitizer for Oxidation of Alkanes

“…Several families of such networks utilizing different PSs have been reported, porphyrin (PCN-222, UNLPE-10, PCN-134), perylenediimde (FJI-Y10), anthracene (NNU-32, NNU-37) and pyrene (PCN-822, NU-1000). [16][17][18][19][20][21][22][23] When performing photooxidation reactions however, substrates containing various heteroatoms or carbon-carbon double bonds were commonly investigated, which have elevated reactivity towards ROSs. In contrast, oxidation of less reactive saturated hydrocarbons using photocatalytic networks has seen considerably less exploration.…”