Novel Metal–Organic Framework Cocrystal Strategy for Significantly Enhancing Photocatalytic Performance

Abstract

Owing to their high carrier recombination speed and low spectral utilization, it is difficult to further improve the performance of photocatalysts. In this study, a novel metal–organic framework (MOF) self‐assembled cocrystal material is developed. The guest molecule is inserted and self‐assembled with the existing MOF ligand to form an organic cocrystal. The highly ordered molecular arrangement and tight intermolecular distances between donor and acceptor molecules promote a strong π–π charge transfer interaction, facilitating the migration and separation of photogenerated charge carriers. In addition, efficient redshifts in the absorption wavelength enhance the response to visible light. Further, the unique porous structure of MOFs is beneficial for increasing the interfacial area of photocatalytic reactions, and metal ions can become the center of photogenerated carrier capture, effectively inhibiting carrier recombination. Consequently, the MOF cocrystal demonstrates remarkable efficiency in the degradation of pollutants in water, achieving a noteworthy removal efficiency of 95.31% within 15 min. Moreover, the photocatalyic reaction kinetics constant of the MOF cocrystal is 46.5 times higher, indicating the success of this new strategy in developing highly efficient photocatalytic systems.

Phenanthroline-functionalized donor–acceptor covalent organic frameworks as photo-responsive nanozymes for visual colorimetric detection of isoniazid

“…On the basis of the energy levels, the separation and transfer of photogenerated charges are a crucial influence in photocatalytic applications. 34 As shown in Fig. 3e, the photoluminescence (PL) of the Py-PD COF showed a weaker intensity than that of Py-1P COF, suggesting that the charge recombination process of the Py-PD COF was greatly reduced.…”

Organic Donor‐Acceptor Systems for Photocatalysis

“…Reproduced with permission. [ 119 ] Copyright 2023, Wiley‐VCH. d) Schematic representation of POM clusters by covalent binding in D‐A type COF.…”

“…As shown in Figure 11c , Zhang et al have formed unique MOF cocrystal materials by inserting donor molecules into the ligands of MOFs at the molecular level. [ 119 ] The strong CT interactions not only broaden the absorption spectrum into the infrared optical region, but also shorten the intermolecular stacking distance, allowing the photogenerated carriers to be smoothly transported in the guest molecules, frameworks, and coordination metals, and realizing the photocatalytic performance from scratch. This post‐modified strategy for building D‐A type framework materials is effective, but its stability is something that needs to be further improved.…”

A review of metal–organic framework (MOF) materials as an effective photocatalyst for degradation of organic pollutants

“…Mechanistically, photocatalytic processes involve the excitation of e − from the valence band (VB) to the conduction band (CB) of the photocatalyst material upon absorption of light leading to the formation of e − -h + pairs. 24,25 Subsequently, these charge carriers can participate in redox reactions with adsorbed organic molecules or water, generating ROS like hydroxyl radicals (cOH) and superoxide radicals (cO 2− ) which are mostly responsible for degradation of organic pollutants into less harmful inorganic ions. The rate of these reactions is highly dependent on the availability of these charge carriers and their spatial separation to minimize recombination.…”