Metal-organic Framework Films Research Articles

Cathodic Deposition-Assisted Synthesis of Thin Glass MOF Films for High-Performance Gas Separations.

Glass metal-organic framework (MOF) films can be fabricated from their crystalline counterparts through a melt-quenching process and are prospective candidates for gas separation because of the elimination of the grain boundaries in crystalline MOF films. However, current techniques are limited to producing glass MOF films with a thickness of tens of micrometers, which leads to ultralow gas permeances. Here, we report a novel cathodic deposition-assisted synthesis of glass ZIF-62 films with a thickness as low as ~1 μm. Electrochemical analyses and deposition experiments suggest that the cathodic deposition can lead to pure crystalline ZIF-62 films with a controllable thickness of ~2 μm to ~15 μm. Accordingly, glass ZIF-62 films with a thickness of ~1 μm to ~10 μm can be obtained after a thermal treatment. The fabricated defect-free glass ZIF-62 film measuring 2 μm in thickness shows a remarkable CO2/N2 and CO2/CH4 selectivity of 31.4 and 33.4, respectively, with a CO2 permeance which is over 30 times higher than the best-performing glass ZIF-62 films in literature.

Cathodic Deposition‐Assisted Synthesis of Thin Glass MOF Films for High‐Performance Gas Separations

Glass metal‐organic framework (MOF) films can be fabricated from their crystalline counterparts through a melt‐quenching process and are prospective candidates for gas separation because of the elimination of the grain boundaries in crystalline MOF films. However, current techniques are limited to producing glass MOF films with a thickness of tens of micrometers, which leads to ultralow gas permeances. Here, we report a novel cathodic deposition‐assisted synthesis of glass ZIF‐62 films with a thickness as low as ~1 μm. Electrochemical analyses and deposition experiments suggest that the cathodic deposition can lead to pure crystalline ZIF‐62 films with a controllable thickness of ~2 μm to ~15 μm. Accordingly, glass ZIF‐62 films with a thickness of ~1 μm to ~10 μm can be obtained after a thermal treatment. The fabricated defect‐free glass ZIF‐62 film measuring 2 μm in thickness shows a remarkable CO2/N2 and CO2/CH4 selectivity of 31.4 and 33.4, respectively, with a CO2 permeance which is over 30 times higher than the best‐performing glass ZIF‐62 films in literature.

Crosslinking-induced patterning of MOFs by direct photo- and electron-beam lithography

Metal-organic frameworks (MOFs) with diverse chemistry, structures, and properties have emerged as appealing materials for miniaturized solid-state devices. The incorporation of MOF films in these devices, such as the integrated microelectronics and nanophotonics, requires robust patterning methods. However, existing MOF patterning methods suffer from some combinations of limited material adaptability, compromised patterning resolution and scalability, and degraded properties. Here we report a universal, crosslinking-induced patterning approach for various MOFs, termed as CLIP-MOF. Via resist-free, direct photo- and electron-beam (e-beam) lithography, the ligand crosslinking chemistry leads to drastically reduced solubility of colloidal MOFs, permitting selective removal of unexposed MOF films with developer solvents. This enables scalable, micro-/nanoscale (≈70 nm resolution), and multimaterial patterning of MOFs on large-area, rigid or flexible substrates. Patterned MOF films preserve their crystallinity, porosity, and other properties tailored for targeted applications, such as diffractive gas sensors and electrochromic pixels. The combined features of CLIP-MOF create more possibilities in the system-level integration of MOFs in various electronic, photonic, and biomedical devices.

Layer‐By‐Layer Chiral Induction of Fluorene‐Based Metal–Organic Framework Films for Circularly Polarized Luminescence Sensing of Enantiomers

AbstractDeveloping films of chiral metal–organic frameworks (MOFs) with high circular polarization luminescence (CPL) is facing a great challenge for chiral sensing applications. Herein, a layer‐by‐layer chiral induction method is first reported to prepare enantiopure MOF films for CPL sensing. By layer‐by‐layer induction with the chiral inductor camphorsulfonic acid, fluorene‐based chiral MOF D/L‐ZnHF‐SO2 film (HF‐SO2 = 3,7‐Dibenzothiophenedicarboxylate, 5,5‐dioxide) with preferential growth orientation and homogeneous surface are prepared, which shows strong chiral feature and CPL with higher asymmetry factor of ±0.073. In addition, by mixed ligand approach, the isostructural fluorene ligand 9‐fluororenone‐2,7‐dicarboxylate is chosen to replace part of HF‐SO2 for preparing a series of chiral MOF films with tunable CPL emission. Furthermore, the prepared chiral MOF films with strong CPL performance are further utilized for enantiomers sensing. The CPL changes consisted with enantioselective adsorption results showed that D/L‐ZnHF‐SO2 film has good discrimination against chiral R/S‐phenylethylamine enantiomers, first reporting chiral MOF‐based candidates for the application in CPL sensing of enantiomers. This work provides a facile and effective approach for preparing chiral MOF films materials with high and tunable CPL performance, and also gives a new way to achieve CPL sensing of chiral enantiomers.

Photosynthesis of H2O2 in pure water over 2D metal-organic frameworks film by co-doping Ga and porphyrin

Hydrogen peroxide (H2O2) is a clean oxidizing agent and potential energy carrier. Photocatalytic H2O2 production has garnered increased attention due to its green and energy-saving process. However, existing photocatalysts face several challenges, such as limited response to visible light, the requirement for sacrificial reagents, and complications in powder recycling. In this work, we synthesized two-dimensional (2D) NH2-MIL-53(Al) films co-modified with Ga and tetrakis (4-carboxyphenyl) porphyrin (TCPP) with enhanced photocatalytic activity of 268.7 µmol∙g−1∙h−1 from only O2 and pure H2O, reaching 3.5 times higher than pure NH2-MIL-53(Al). Notably, in comparison with other reported MOF photocatalysts, NMA-Ga5%-L30 stands out with the highest photocatalytic H2O2 generation activity in a pure water system under visible light. Moreover, this sample film was readily recovered from a photocatalytic system and exhibits significant cycling stability. The heightened photocatalytic activity is attributed to the dual modification, which not only reduces the photogenerated band gap but also promotes the charge carrier’s separation and transfer. This work provides a strategy for the design of MOFs-based photocatalysts with easy recycle properties for artificial photosynthesis of H2O2.

Electro-Induced Phase Transformation of a Conductive Metal-Organic Framework Film for Nonlinear Optical Switching.

Achieving metal-organic frameworks (MOFs) with nonlinear optical (NLO) switching is profoundly important. Herein, the conductive MOFs Cu-TCNQ phase I (Ph-I) and phase II (Ph-II) films were prepared using the liquid-phase-epitaxial layer-by-layer spin-coating method and steam heating method, respectively. Electronic experiments showed that the Ph-II film could be changed into the Ph-I film under an applied electric field. The third-order NLO results revealed that the Ph-I film had a third-order nonlinear reverse saturation absorption (RSA) response and the Ph-II film displayed a third-order nonlinear saturation absorption (SA) response. With increases in the heating time and applied voltage, the third-order NLO response realized the reversible transition between SA and RSA. The theoretical calculations indicated that Ph-I possessed more interlayer charge transfer, resulting in a third-order nonlinear RSA response that was stronger than that of Ph-II. This work applies phase-transformed MOFs to third-order NLO switching and provides new insights into the nonlinear photoelectric applications of MOFs.

Enhanced Ceftriaxone Determination using a Glassy Carbon Electrode Modified with a Cr‐based Metal‐Organic Framework Film Stabilized by β‐Cyclodextrin Polymer

AbstractA selective amperometric sensor was developed to detect the antibiotic ceftriaxone (CEF) using a composite film of poly(β‐cyclodextrin) and a metal‐organic framework (MOF). The sensor was obtained by electro‐polymerizing β‐cyclodextrin (β‐CD) onto a glassy carbon electrode (GCE) previously coated with a MIL‐101(Cr) MOF film. This design prevents MOF particles’ loss during extended electrode use. The MOF was structurally characterized using scanning electron microscopy, X‐ray diffraction, N2 adsorption‐desorption isotherms (BET method) and FTIR spectroscopy. Electrochemical impedance spectroscopy and cyclic voltammetry were used to assess the GCE/MIL‐101(Cr)‐pβ‐CD sensor, revealing reduced charge transfer resistance and enhanced sensitivity to CEF. Differential pulse voltammetry was then employed for CEF determination. Under optimized conditions, the sensor exhibited high sensitivity, a broad linear working range of 0.5 to 6 μM (R2=0.991), and a low detection limit of 0.34±0.02 μM (0.19±0.01 mg L−1). The selectivity of the sensor was evaluated in the presence of potential interferences such as organic acids, antibiotics and selected ions expected to affect the CEF signal. In an application to quantify a pharmaceutical formulation, the sensor displayed an impressive recovery rate of 98.3 % compared to results obtained using high‐performance liquid chromatography.

Design and Synthesis of Transferrable Macro-Sized Continuous Free-Standing Metal-Organic Framework Films for Biosensor Device.

Metal organic framework (MOF) films have attracted abundant attention due to their unique characters compared with MOF particles. But the high-temperature reaction and solvent corrosion limit the preparation of MOF films on fragile substrates, hindering further applications. Fabricating macro-sized continuous free-standing MOF films and transferring them onto fragile substrates are a promising alternative but still challenging. Here, a universal strategy to prepare transferrable macro-sized continuous free-standing MOF films with the assistance of oxide nanomembranes prepared by atomic layer deposition and studied the growth mechanism is developed. The oxide nanomembranes serve not only as reactant, but also as interfacial layer to maintain the integrality of the free-standing structure as the stacked MOF particles are supported by the oxide nanomembrane. The centimeter-scale free-standing MOF films can be transferred onto fragile substrates, and all in one device for glucose sensing is assembled. Due to the strong adsorption toward glucose molecules, the obtained devices exhibit outstanding performance in terms of high sensitivity, low limit of detection, and long durability. This work opens a new window toward the preparation of MOF films and MOF film-based biosensor chip for advantageous applications in post-Moore law period.

Fabrication of NiCo Bimetallic MOF Films on 3D Foam with Assistance of Atomic Layer Deposition for Non-Invasive Lactic Acid Sensing.

Lactic acid (LA) is an important downstream product of glycolysis in living cells and is abundant in our body fluids, which are strongly associated with diseases. The development of enzyme-free LA sensors with high sensitivity and low consumption remains a challenge. 2D metal-organic frameworks (MOFs) are considered to be promising electrochemical sensing materials and have attracted much attention in recent years. Compared to monometallic MOFs, the construction of bimetallic MOFs (BMOFs) can obtain a larger specific surface area, thereby increasing the exposed active site. 3D petal-like NixCoy MOF films on nickel foams (NixCoy BMOF@Ni foams) are successfully prepared by combining atomic layer deposition-assisted technology and hydrothermal strategy. The established NixCoy BMOF@Ni foams demonstrate noticeable LA sensing activity, and the study is carried out on behalf of the Ni1Co5 BMOF@Ni foam, which has a sensitivity of up to 9030 μA mM-1 cm-2 with a linear range of 0.01-2.2 mM and the detection limit is as low as 0.16 μM. Additionally, the composite has excellent stability and repeatability for the detection of LA under a natural air environment with high accuracy and reliability. Density functional theory calculation is applied to study the reaction process between composites and LA, and the result suggests that the active site in the NiCo BMOF film favors the adsorption of LA relative to the active site of monometallic MOF film, resulting in improved performance. The developed composite has a great potential for the application of noninvasive LA biosensors.

Universal Strategy for Metal-Organic Framework Growth: From Cascading-Functional Films to MOF-on-MOFs.

Transformation of metal-organic framework (MOF) particles into thin films is urgently needed for the persistent development of well-applicable devices, and recently emerging functional-integrated hybrid frameworks. Although some flexible polymers and exclusive modification approaches have been proposed, the additive-free and widely applicable strategy has not been reported, hampering the deep investigation of the structure-performance relationship. A universal strategy for the in situ growth of large-area and continuous MOF films with controllable microstructures is introduced, through the modification of multi-scale and multi-structure substrates with poly(4-vinylpyridine) as the anchor to capture metal ions via Coulomb attraction. Based on the clarified structure-adsorption-separation mechanisms, the customized devices fabricated by in situ growth can achieve highly selective adsorption and excellently synergetic separation of various industrially relevant isomers. In addition, this strategy is also feasible for the construction of MOF-on-MOFs with varied lattice parameters. This strategy is easy to implement and will be widely applicable to the surface growth of diverse MOFs on desired substrates, and provides a new concept for developing hybrid MOFs integrating with customized functionalities.

One-step in situ preparation of Zr(Ti)-MOFs on titanium alloys at a low temperature of 80°C and atmospheric pressure

Preparing metal-organic frameworks (MOFs) film in situ on the surface of the Ti-6Al-4V (TC4) titanium alloy is challenging owing to the dense and stable surface TiO2 passive film. In this study, titanium-doped zirconium-based MOFs (Zr(Ti)-MOFs) film was constructed in situ on the TC4 alloy in one step at a low temperature and atmospheric pressure, with ZrCl4 as the source of Zr metal ions. ZrCl4 attacked and dissolved the TiO2 film to form Zr-O-Ti bonds on the surface of TC4 to provide nucleation sites for further reactions. At the same time, Zr4+ and dissolved Ti4+ combined in solution to form Ti containing Zr-O cluster nodes, which aggregated and grafted to the Zr-O-Ti bonds on the substrate surface, and reacted with organic ligands (terephthalic acid) to form Zr(Ti)-MOFs film. The Ti4+ dissolved from the TC4 participate in the Zr-MOFs formation, thereby changing the high temperature and high-pressure conditions required for the traditional preparation of Zr-MOFs (UiO-66). The in situ preparation of Zr(Ti)-MOFs on TC4 was achieved at 80 °C under atmospheric pressure conditions. This study elucidated the growth mechanism of Zr(Ti)-MOFs on the TC4 surface, providing a reference for the design and In-situ preparation of multifunctional MOFs on the TC4 titanium alloy.

An ultrathin and crack‐free metal‐organic framework film for effective polysulfide inhibition in lithium–sulfur batteries

AbstractDue to their extensive microporous structure, metal‐organic frameworks (MOFs) find widespread application in constructing modification layers, functioning as ion sieves. However, the modification layers prepared by existing methods feature gaps between MOFs that are noticeably larger than the inherent MOF pore dimensions. Polysulfides and lithium ions unavoidably permeate through these gaps, hindering the full exploitation of the structural advantages. Herein, an ultrathin (20 nm) and crack‐free MOF film is formed on the separator by atomic layer deposition for the first time. Based on the separator, the mechanism of different MOF layers has been verified by phase field simulation and in situ Raman spectroscopy. The results accurately prove that the MOF particle layer can relieve the shuttle of polysulfides, but it does not have the effect of homogenizing lithium ions. Only the ultrathin and crack‐free MOF film with proper pore size can act as the ion sieve for both polysulfides and lithium ions. As a result, under the test condition of 2 mA cm−2–2 mAh cm−2, the overpotential of the Li/Li symmetric battery is only 18 mV after 2500 h. The capacity retention rate of the lithium–sulfur battery is 95.6% after 500 cycles and 80% after 1000 cycles at 2 C.

Deep Learning Enabled SERS Identification of Gaseous Molecules on Flexible Plasmonic MOF Nanowire Films.

Through the capture of a target molecule at the metal surface with a highly confined electromagnetic field induced by surface plasmon, surface enhanced Raman spectroscopy (SERS) emerges as a spectral analysis technology with high sensitivity. However, accurate SERS identification of a gaseous molecule with low density and high velocity is still a challenge due to its difficulty in capture. In this work, a flexible paper-based plasmonic metal-organic framework (MOF) film consisting of Ag nanowires@ZIF-8 (AgNWs@ZIF-8) is fabricated for SERS detection of gaseous molecules. Benefiting from its micronanopores generated by the nanowire network and ZIF-8 shell, the effective capture of the gaseous molecule is achieved, and its SERS spectrum is obtained in this paper-based flexible plasmonic MOF nanowire film. With optimal structure parameters, spectra of gaseous 4-aminothiophenol, 4-mercaptophenol, and dithiohydroquinone demonstrate that this film has good SERS performance, which could maintain obvious Raman signals within 30 days during reproducible detection. To realize SERS identification of gaseous molecules, deep learning is performed based on the SERS spectra of the mixed gaseous analyte obtained in this flexible porous film. The results point out that an artificial neural network algorithm could identify gaseous aldehydes (gaseous biomarker of colorectal cancer) in simulated exhaled breath with high accuracy at 93.7%. The integration of the flexible paper-based film sensors with deep learning offers a promising new approach for noninvasive colorectal cancer screening. Our work explores SERS applications in gaseous analyte detection and has broad potential in clinical medicine, food safety, environmental monitoring, etc.

Fabrication of sponge-like Zn-dpNDI-MOF film optical waveguides for study of improved optical gas adsorbility and kinetics

A sponge-like zinc metal-organic framework film, [Zn2(TpA)2(dpNDI)]n (Zn-dpNDI-MOF, where, TpA = terephthalic acid; dpNDI = N,N′-dipyridylnaphthalenediimide), was prepared on a tin-doped glass optical waveguide (OWG) substrate using a solvothermal method. The effect of the solvothermal growth time on the morphology, optical characteristics, and gas adsorption properties of the Zn-dpNDI-MOF film was investigated. The gas adsorption sensitivity was assessed by comparing the growth of Zn-dpNDI-MOF film OWGs under in situ and UV-light illumination conditions. The results revealed that the Zn-dpNDI-MOF films were optically transparent and exhibited a sponge-like structure after 20 h of continuous growth. Additionally, they demonstrated a higher adsorption response to xylene and ethylenediamine (EDA) gases because of the intrinsic electron deficiencies of the framework and the higher molar refractive indices and dipoles of xylene and EDA compared to other gases. Within the xylene concentration range of 10 ppb–1000 ppm, the OWG film exhibited a fast, improved response. In the static gas adsorption process performed at 283–313 K, the xylene adsorption behaviour of the Zn-dpNDI-MOF film followed a pseudo-second-order (PSO) kinetic model. Within 0–60 min of adsorption time, the amount of xylene gas adsorbed on the unit surface was shows as high as 6.21 μg cm−2. Compared to the in situ grown film, the Zn-dpNDI-MOF film OWGs showed higher sensitivity to xylene gas owing to their higher refractive indices.

Stress-driven recrystallization of pentacene films via diffusion-induced ingress of MOF nanocrystals into the grain boundaries

Metal-organic frameworks (MOFs) have been identified as versatile candidates for producing functional materials for various applications. However, the growth of MOF thin film becomes challenging due to non-availability of a proper solvent that restricts the use of the materials in electronic sensor fabrication. The receptor molecules in sensors are often used to functionalize the semiconducting channel. However, integrating such molecules degrade the crystallinity of channel materials, leading to poor sensor performance. In this work, we report the growth of a MOF (CPO-27-Ni) thin film and the recrystallization of semiconducting pentacene thin films due to diffusion of the crystallites into the grain boundaries. MOF films were successfully spin coated at various revolutions per minute (rpm) on pentacene surfaces. The growth of MOF films was studied using statistical analysis of rough surfaces by utilizing scaling theory to capture the evolution of surface morphologies. The x-ray reflectivity study unveiled the diffusion-induced ingress of the MOF through the grain boundaries of pentacene films that imparts compressive stress within the grains leading to subsequent rearrangement of pentacene molecules in the thin-film phase and recrystallizes the bulk crystallographic phase, which in a way will enhance the device performance.

Vapor-phase zeolitic imidazolate framework-8 growth on fibrous polymer substrates

The use of metal-organic frameworks (MOFs) in practical applications is often hindered by synthesis related challenges. Conventional solution-based approaches rely on hazardous solvents and often form powders that are difficult to integrate into practical devices. On the other hand, vapor-phase approaches generally result in MOF films on silicon substrates that make it difficult to characterize the MOF surface area, which is an important quality indicator. We address these challenges by introducing a solvent-free synthesis method to form MOF–fiber composites, which can be more easily integrated into devices. Additionally, these vapor-phase-formed MOF–fiber composites are compatible with Brunauer–Emmett–Teller surface area analysis to characterize MOF quality. Atomic layer deposition is used to form a ZnO film on polypropylene, polyester, and nylon fibrous substrates, which is subsequently converted to zeolitic imidazolate framework-8 (ZIF-8) using 2-methylimidazole vapor. We describe the effects of the ZnO film thickness and MOF conversion conditions on MOF crystallinity and surface area. We report a ZIF-8 surface area of ∼1300 m2/gMOF, which is comparable to reported surface areas of ∼1250–1600 m2/gMOF from conventional synthesis techniques, demonstrating good quality of the solvent-free MOF–fiber composites. We expect these results to extend vapor-phase MOF formation to new, practical substrates for advanced sensing and catalytic applications.

Unravelling abnormal in-plane stretchability of two-dimensional metal-organic frameworks by machine learning potential molecular dynamics.

Two-dimensional (2D) metal-organic frameworks (MOFs) hold immense potential for various applications due to their distinctive intrinsic properties compared to their 3D analogues. Herein, we designed a highly stable NiF2(pyrazine)2 2D MOF in silico with a two-dimensional periodic wine-rack architecture. Extensive first-principles calculations and molecular dynamics (MD) simulations based on a newly developed machine learning potential (MLP) revealed that this 2D MOF exhibits huge in-plane Poisson's ratio anisotropy. This results in anomalous negative in-plane stretchability, as evidenced by an uncommon decrease in its in-plane area upon the application of uniaxial tensile strain, which makes this 2D MOF particularly attractive for flexible wearable electronics and ultra-thin sensor applications. We further demonstrated the unique capability of MLP to accurately predict the finite-temperature properties of MOFs on a large scale, exemplified by MLP-MD simulations with a dimension of 28.2 × 28.2 nm2, relevant to the length scale experimentally attainable for the fabrication of MOF films.

Vapor-phase methods for synthesizing metal-organic framework thin films

<p>Due to their unique structures and exceptional physical and chemical properties, metal-organic framework (MOF) materials have garnered extensive attention in various fields, including catalysis, separations, sensing, and optics. Compared with powders or bulk MOF materials, MOF thin films exhibit large vertical and horizontal dimensions, higher specific surface areas, and abundant active sites and undergo facile combination with other functional centers for adsorption/separation, catalysis, and photoelectronic device applications. Among the methods used in preparing MOF thin films, the vapor phase approach enables more effective growth of MOF films with controllable thicknesses, uniformity, and compatibility; thus, it has attracted significant interest. This extensive review presents four vapor-phase approaches for preparing MOF thin films: the steam-assisted conversion method, vapor-phase transformations of metal oxide templates, vapor-phase linker exchange, and the atomic layer deposition/molecular layer deposition method. We summarize the advantages and disadvantages of these different vapor-phase-based methods for thin-film preparation, aiming to promote their use in precise and controllable surface syntheses.</p>

Vertical MOF film supported on an organic–inorganic mixed substrate for complex wastewater purification

Flexible metal–organic framework (MOF) films are greatly desired for the separation of hazardous molecules and ions from wastewater. The current MOF films are usually horizontally deposited on the substrates, and thus restricted by brittleness, low exposure of surface area, as well as poor separation functions. Here, an organic–inorganic mixed substrate is firstly fabricated by growing hydroxyapatite (HA) nanowire arrays on the cellulose fiber (CF). Subsequently, MIL-100(Fe) nanocrystals are assembled on the surfaces of HA nanowire arrays through a layer-by-layer manner, leading to a unique vertical MOF film. The resulting vertical MOF films show competitive advantages over the horizontal counterparts: (i) they show excellent flexibility and they are tolerant to serious physical damage; (ii) they have multiple separation functions including ion exchange of HA, excellent adsorption of MOFs, and strong electrostatic interaction of CF; and (iii) the agglomeration of MIL-100(Fe) nanocrystals is effectively suppressed. Therefore, the average roughness, specific surface area, and average pore size of films are optimized. As a result, the vertical MOF films show universal separation of positively/negatively-charged dyes and Pb2+ ion, with high removal rates of > 94 %. More appealing, the mixed pollutants in the complex wastewater can be one-step separated through the vertical MOF films, with high removal rates of > 96 %.

Photoswitchable Radical State in Nanoporous Metal-Organic Framework Films with Embedded Hexaarylbiimidazole.

Photoresponsive materials enable dynamic remote control of their fundamental properties. The incorporation of photochromic molecules in nanoporous metal-organic frameworks (MOFs) provides a unique opportunity to tailor the material properties, including the interaction between the MOF host and guest molecules in the pores. Here, a MOF film of type HKUST-1 with embedded hexaarylbiimidazole (HABI), undergoing reversible light-induced reactions between the stable dimer state and the metastable radical state, is presented. The switching between the dimer and radical form is shown by infrared, UV-vis, and electron paramagnetic resonance (EPR) spectroscopy. By transient uptake experiments with ethanol and methanol as probe molecules, we show that the dimer-radical switching impacts the host-guest interaction and, in particular, modifies the uptake amount and diffusion coefficient of the guest molecules. For ethanol, the diffusion slows down by 75%. This research presents the first MOF material with photoswitchable (meta)stable dimer and radical molecules, and it contributes to the advancement of photoresponsive nanoporous materials.