Cadmium-based Metal-organic Framework Research Articles

Engineered Amine-Functionalized Metal-Organic Framework to Fabricate a Composite for Next-Generation Asymmetric Supercapacitors with Ultrahigh Performance: Modulating the Energy Storage Barrier.

The present work summarizes the fabrication of an amine-functionalized cadmium-based metal-organic framework (MOF), {[Cd(AT)(BP)]·4DMF}n or Cd_AT-BP, by adopting a simple solvothermal approach using 2-aminoterephthalic acid (AT) as the main linker, while 4,4'-bipyridyl (BP) as an auxiliary linker. The structure of Cd_AT-BP was validated by the single-crystal X-ray diffraction technique that revealed the formation of an overall three-dimensional network with BP acting as a bridge between the 2D sheets of the MOF. The robust framework of Cd_AT-BP decorated with a free amine functional group was utilized for energy storage application. The electrochemical measurements of Cd_AT-BP revealed a maximum areal capacitance of 9.8 mF/cm2 at a scan rate of 5 mV/s. Further, to enhance the practical utility of Cd_AT-BP in energy storage devices, two composites of Cd_AT-BP with reduced graphene oxide (rGO) and multiwalled carbon nanotubes (CNTs), viz., Cd_AT-BP/rGO and Cd_AT-BP/CNT, were prepared by adopting a facile ultrasonication approach. The synthesized Cd_AT-BP/rGO and Cd_AT-BP/CNT composites displayed an impressive areal capacitance of 117 and 37 mF/cm2 (58.5 and 17.5 F/g) at a scan rate of 5 mV/s, respectively, and a capacitance retention of up to 118 and 100% after 5000 cycles at a constant current density of 5 mA/cm2. The highest energy density of about 4.23 mW h/cm2 (2.12 W h/kg) at a current density of 1 mA/cm2 was shown by Cd_AT-BP/rGO among all the three materials attributable to the layered structure of rGO, providing a larger surface area accessible for ion adsorption. Enticed by the remarkable outcomes exhibited by Cd_AT-BP/rGO, we fabricated a two-electrode asymmetric supercapacitor (ASC) device. The developed ASC device revealed energy and power densities of 26.7 mW h/cm2 (13.4 W h/kg) and 3760 mW/cm2 (1880 W/kg), respectively, with a galvanostatic charge-discharge stability of up to 10,000 cycles. The findings identify Cd_AT-BP/rGO as a potential contender for future-generation supercapacitors.

Multifunctional Cadmium-Based Metal–Organic Frameworks for the Detection of Ion and Molecule in Aqueous Media

Multifunctional Cadmium-Based Metal–Organic Frameworks for the Detection of Ion and Molecule in Aqueous Media

Highly Emissive and Robust Cd-Based MOF with an Unprecedented Topology for Tetracycline Sensing.

Herein, an unprecedented cadmium-based metal-organic framework (JNU-106) fabricated by utilizing pyrazole-functionalized tetraphenylethylene ligands (Py-TPE) and rod-shaped secondary building units is reported, possessing a new (3,3,3,6,6,8)-connected topological network. Thanks to the ingeniously designed intramolecular charge transfer behavior, which originates from the congruent coplanarity between Py and TPE, JNU-106 exhibits intense green luminescence with a quantum yield increased by 1.5 times. The phenomenon of remarkable fluorescence quenching of JNU-106 reveals that it possesses extremely high anti-interference performance, superior sensitivity, and dedicated selectivity toward tetracycline antibiotics (TCAs) in aqueous solutions, which are comparable to those of the state-of-the-art porous sensing compounds. Taking the theoretical calculations and experimental results into account, the luminescence quenching is mainly attributed to the internal filtration effect and the static quenching effect. Considering the portable and rapid performance of JNU-106-based testing strips for sensing TCAs, the fabricated JNU-106 provides an alternative for ecological monitoring and environmental governance.

A two-dimensional cadmium-based metal–organic framework as an excellent probe: highly selective luminescent “turn on” detection of tetrahydrofuran and quantitative analysis of water

A multifunctional Cd-MOF as an excellent probe exhibits highly selective luminescent “turn on” detection of tetrahydrofuran and quantitative analysis of water.

Structural Change and Radical Generation of a Cadmium-Based Metal-Organic Framework Induced by an Electric Field.

Herein we report the structural change and radical generation of a cadmium-based metal-organic framework (Cd-MOF) induced by external electric fields. Under a weaker single electric field, different coordination modes of Cd-L lead to 3D → 2D structural change. Under stronger superposed electric fields, Cd-MOF was excited to produce a stable free radical. This study will provide a new avenue for the controlled assembly of MOFs.

New 3D Cd (II) metal-organic framework as a highly sensitive luminescent sensor for detection of the 4-nitrophenol and nitrofuran antibiotics

The overused of nitroaromatic explosives and antibiotics had led to severe environment and health issues. The detection on nitroaromatic explosives and antibiotics with high selective and sensitive is pressing need. Herein, a new cadmium-based metal–organic framework (MOF), namely {[(CH3)2NH2]2[Cd3(TCPPDA)2]·5DMF·8H2O}nMOF-1 (H4TCPPDA = N,N,N’,N’-Tetrakis(4-carboxyphenyl)-1,4-phenylenediamine) had been successfully synthesized and characterized. Single crystal X-ray diffraction analysis displayed that MOF-1 possesses 3D (4,8)-connected framework with the Schläfli symbol of {42.6}2{44.62.87.102} comprising trinuclear [Cd3(COO)8] SBUs. The detection ability of MOF-1 toward nitroaromatic explosives and antibiotics were evaluated. Notably, MOF-1 had high selectivity and sensitivity for 4-Nitrophenol (4-NP) and nitrofuran antibiotics (nitrofurazone, NFZ, nitrofurantoin, NFT) with low detection limits of 7.5, 1.39 and 1.23 μM. Furthermore, the possible quenching mechanisms were also explored by calculations and experiments.

Photo-Stimuli-Responsive Dual-Emitting Luminescence of Spiropyran-Encapsulated Metal-Organic Framework for Dynamic Information Encryption.

The development of photo-stimuli-responsive luminescent materials is essential to address emerging demands in encryption security. Here, we report a novel photo-stimuli-responsive dual-emitting luminescent material ZJU-128⊃SP (SP = spiropyran), which was obtained by encapsulating spiropyran molecule into a cadmium-based metal-organic framework (MOF), [Cd3 (TCPP)2 ]·4DMF·4H2 O (ZJU-128, H4 TCPP = 2,3,5,6-tetrakis (4-carboxyphenyl)pyrazine). This MOF/dye composite ZJU-128⊃SP exhibits a blue emission from ligand of ZJU-128 at 447nm and a red emitting around 650nm of spiropyran. Utilizing the photoisomerization of spiropyran from ring-closed to ring-open form under UV light irradiation, significant fluorescence resonance energy transfer process between ZJU-128 and spiropyran is achieved. As a result, the blue emission of ZJU-128 is gradually decreased while the red emission of spiropyran increased. This dynamic fluorescent behavior can fully recover to original state when exposed to visible light (> 405nm). By taking advantage of the time-dependent fluorescence, dynamical anti-counterfeiting pattern and multiplexed coding are successfully developed based on ZJU-128⊃SP film. This work provides an inspiring point for the design of information encryption materials with higher security requirements. This article is protected by copyright. All rights reserved.

Effect of Electrolytic Cations on a 3D Cd-MOF for Supercapacitive Electrodes

A cadmium-based metal-organic framework (Cd-MOF) is synthesized in a facile manner at ambient temperature by an easy slow diffusion process. The three-dimensional (3D) structure of Cd-MOF is authenticated by single-crystal X-ray diffraction studies and exhibits a cuboid-shaped morphology with an average edge length of ∼1.13 μm. The prepared Cd-MOF was found to be electroactive in nature, which resulted in a specific capacitance of 647 F g-1 at 4 A g-1 by maintaining a retention of ∼78% over 10,000 successive cycles in the absence of any binder. Further, to distinguish the efficiency of Cd-MOF electrodes, different electrolytes (NaOH, KOH, and LiOH) were explored, wherein NaOH revealed a higher capacitive response due to its combined effect of ionic and hydrated ionic radii. To investigate the practical applicability, an asymmetric supercapacitor (ASC) device is fabricated by employing Cd-MOF as the positive electrode and activated carbon (AC) as the negative electrode, enabling it to light a commercial light-emitting diode (LED) bulb (∼1.8 V). The as-fabricated ASC device delivers comparable energy density and power density.

Two Stable Cd-MOFs as Dual-Functional Materials with Luminescent Sensing of Antibiotics and Proton Conduction.

Construction and investigation of dual-functional metal-organic frameworks (MOFs) with luminescent sensing and proton conduction provide widespread applications in clean energy and environmental monitoring fields. By selecting a phosphonic acid ligand 4-pyridyl-CH2N(CH2PO3H2)2 (H4L) and coligand 2,2'-biimidazole (H2biim), two cadmium-based MOFs [Cd1.5(HL)(H2biim)0.5] (1) and (H4biim)0.5·[Cd2(L)(H2biim)Cl] (2) with different structures and properties have been hydrothermally synthesized by controlling reaction temperature. Based on the excellent thermal and chemical stabilities, and good luminescent stabilities in water solution, 1 and 2 can serve as luminescent sensors of chloramphenicol (CAP) with different quenching constant (KSV) values and detection limits (LODs) in water, simulated environmental system, and real fish water system. Meanwhile, different sensing effects and possible sensing mechanisms are analyzed in detail. Moreover, 1 and 2 can also serve as good proton-conducting materials. The proton conductivities can reach up to 1.41 × 10-4 S cm-1 for 1 and 1.02 × 10-3 S cm-1 for 2 at 368 K and 95% relative humidity (RH). Among them, 2 shows better luminescent sensing and proton conduction performance than 1, which indicates that different crystal structures have a great impact on the properties of MOFs. Through the discussion of the relationship between structures and properties in detail, the possible reasons for the differences in properties are obtained, which can provide theoretical guidance for the rational design of this kind of dual-functional MOFs in the future.

Synthesis and characterization of a 2-periodic cadmium-based metal-organic framework: A study on reversible water adsorption

A previously-reported cadmium-based two-periodic metal-organic framework [Cd1.5(BTC)(H2O)4.5]n·nH2O (CP1) has been re-synthesized, where H3BTC = 1,3,5-benzenetricarboxylic acid. CP1 was characterized with single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD) followed by various thermal analyses such as thermogravimetric analysis (TGA), hot stage microscopy (HSM) and differential scanning calorimetry (DSC). CP1 is composed of 2-periodic layers, which are interdigitated. Heating can effectively remove the uncoordinated and coordinated water molecules resulting in an amorphous product CP1′. The original framework can be regenerated by readsorption of water from the atmosphere, indicating that the dehydration is reversible.

Dynamic Metal-Iodide Bonds in a Tetracoordinated Cadmium-Based Metal-Organic Framework Boosting Efficient CO2 Cycloaddition under Solvent- and Cocatalyst-Free Conditions.

Due to the inherent thermodynamic stability and kinetic inertness of CO2, heterogeneous catalytic conversion of CO2 to cyclic carbonates often requires harsh operating conditions, high temperature and high pressure, and the addition of cocatalysts. Therefore, the development of efficient heterogeneous catalysts under cocatalyst-free and mild conditions for CO2 conversion has always been a challenge. Herein, an infrequent tetracoordinated Cd-MOF was synthesized and used to catalyze CO2 cycloaddition reactions efficiently without the addition of any cocatalyst, and its catalytic mechanism was systematically investigated through a series of experiments, including fluorescence analysis, X-ray photoelectron spectroscopy, microcalorimetry, and density functional theory (DFT) calculation. Cd-MOF features a 3D supermolecule structure with 1D 11.6 × 7.7 Å2 channels, and the abundant Lewis acid/base and I- sites located in the confined channel boost efficient CO2 conversion with a maximum yield of 98.2% and a turnover number value of 1080.11 at 60 °C and 0.5 MPa, far surpassing most pristine MOF-based catalytic systems. A combined experimental and DFT calculation demonstrates that the exposed Cd(II) Lewis acid sites rapidly participate in coordination to activate the epoxides, and the resulting large steric hindrance facilitates leaving of the coordinated iodide ions in a reversibly dynamic fashion convenient for the rate-determining step ring-opening as a strong nucleophile. Such a pristine MOF catalyst with self-independent catalytic ring-opening overcomes the complicated operation limitation of the traditional cocatalyst-free MOF systems based on encapsulating/postmodifying cocatalysts, providing a whole new strategy for the development of simple, green, and efficient heterogeneous catalysts for CO2 cycloaddition.

Hydrogenation of Carbon Dioxide to Formate Using a Cadmium-Based Metal–Organic Framework Impregnated with Nanoparticles

The burning of fossil fuels to meet energy demands has increased carbon dioxide (CO2) in the atmosphere, causing global warming and associated climate change. Therefore, new materials are being developed to capture CO2 effectively, limit its impact on the environment, and store and/or utilise it as an abundant C1 building block. In this study, we investigate a cadmium(II) metal–organic framework, [Cd(bdc)(DMF)]n (MOF1), synthesised by treating benzene-1,4-dicarboxylic acid with four equivalents of [Cd(NO3)2]. MOF1 was then used to support Pd, Ni, and Pt nanoparticles in forming MOF1/Pd MOF1/Ni and MOF1/Pt, respectively. These MOF-based materials were characterised using powder X-ray diffraction (PXRD), Fourier-transform infrared (FTIR), energy-dispersive X-ray spectroscopy (EDX), selected area electron diffraction (SAED), and high-resolution transmission electron microscopy (HR-TEM). MOF1/Pd MOF1/Ni and MOF1/Pt proved highly active in the catalytic hydrogenation of CO2 to formate selectively; in contrast, MOF1 did not hydrogenate CO2 to formate. The MOF1/Pd, MOF1/Ni, and MOF1/Pt catalysts produced formate selectively, with the highest TON of 1500 (TOF of 69 h−1) achieved using MOF1/Pd as the catalyst at 170 °C within 2 h. A formate yield of 98% was obtained, which demonstrates that the combination of nanoparticles and MOFs greatly enhances the catalytic activity of the active sites.

Construction of a Luminescent Cadmium-Based Metal-Organic Framework for Highly Selective Discrimination of Ferric Ions.

Fluorescent metal–organic frameworks (MOFs) are ideal materials for sensors because of their adjustable pore size and functional groups, which provide them with favorable metal ion selective recognition. In this paper, a new cadmium-based MOF was synthesized using Cd(NO3)2·4H2O and 3,3′,5,5′-biphenyltetracarboxylic acid by solvothermal method. CdBPTC owned three types of channels with dimensions of approximately 8.4 × 8.3 Å, 6.0 × 5.2 Å, 9.7 × 8.4 Å along a, b, and c axis, respectively. This MOF has high selectivity to ferric ions and shows excellent anti-inference ability toward many other cations. The results indicate that the fluorescence quenching efficiency of CdBPTC is close to 100% when the concentration of Fe3+ reaches 1.0 × 10−3 mol·L−1. Moreover, the luminescent intensity at 427 nm presents a linear relationship at a concentration range of 2.0 × 10−4~7.0 × 10−4 mol·L−1, which can be quantitatively expressed by the linear Stern–Volmer equation I0/I = 8489 [Fe3+] − 0.1400, which is comparable to the previously reported better-performing materials. Competitive energy absorption and ion exchange may be responsible for the variation in fluorescence intensity of CdBPTC in different Fe3+ concentrations.

A multifunctional cadmium-based metal-organic framework from a tricarboxylate ligand showing sensing and sensitization

A luminescent-active cadmium-based 3D microporous metal-organic framework [Cd3 (cia)2 (4,4′-bipy) (H2O)2]n (MOF-1, H3cia ​= ​2-(4-carboxylphenoxy)terephthalic acid, 4,4′-bipy ​= ​4,4-bipyridine) was synthesized by choice of a V-shaped asymmetrical tricarboxylate ligand, exhibiting impressive high thermal stability and water stability. More importantly, it acts as luminescence sensor, showing highly selective and sensitive detection on nitrobenzene, Fe3+, Cr2O72− in aqueous solution by quenching effects. And the limit of detection (LOD) values of NB, Fe3+and Cr2O72− are 5.35 ​× ​10−5 ​M, 7.06 ​× ​10−5 ​M, 1.82 ​× ​10−5 ​M, respectively. Besides, MOF-1 can also exhibit the excellent antenna probing performance on Tb3+ ions through efficient energy transfer. In general, the excellent activities of optical-sensing, and sensitization properties for MOF-1 are attributed to active metal sites and accessible porous structure.

Preparation, Characterization of Novel Cadmium-Based Metal-Organic Framework for Using as a Highly Selective and Sensitive Modified Carbon Paste Electrode in Determination of Cu(II) Ion

ABSTRACT A new organic linker Schiff base (H2L) derived from 4-aminobenzoic acid and 2-carboxybenzaldehyde has been successfully synthesized and characterized. The synthesized linker Schiff base was designed to be used in preparation of a new cadmium-based metal-organic framework (Cd-MOF) by sonochemical synthesis, and characterized by using Fourier-transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), Brunauer-Emmett-Teller (BET), scanning electron microscope (SEM), energy dispersive X-ray (EDX), and thermal analysis. Under an optimum set of synthesis conditions, uniform cubic crystals with average size 44–69 nm and a Langmuir surface area of 163.461 m2/g were produced within 60–75 min by crystal system orthorhombic. The synthesized Cd-MOF was incorporated as an ionophore in a carbon paste electrode for Cu(II) ion determination in different real water samples. The proposed carbon paste electrode showed a Nernstian slope of 30.15 ± 0.35 mV decade−1 covering a linear range of 1.0 × 10−7 – 1.0 × 10−1 mol L−1 and the detection limit was 7.5 × 10−8 mol L−1 with long-time stability of more than two months over pH range of 2.5–6.5 and fast response time of 10 s. The proposed sensor was highly selective for Cu(II) ions. The synthesized Cd-MOF had mesoporous structure and this supported the mechanism of Cu(II) ion successful determination.

Polyvinylpyrrolidone-assisted synthesis of highly water-stable cadmium-based metal-organic framework nanosheets for the detection of metronidazole.

Recently, much effort has been dedicated to ultra-thin two-dimensional metal–organic framework (2D MOF) nanosheets due to their outstanding properties, such as ultra-thin morphology, large specific surface area, abundant modifiable active sites, etc. However, the preparation of high-quality 2D MOF nanosheets in good yields still remains a huge challenge. Herein, we report 2D cadmium-based metal–organic framework (Cd-MOF) nanosheets prepared in a one-pot polyvinylpyrrolidone (PVP)-assisted synthesis method with high yield. The Cd-MOF nanosheets were characterized with good stability and dispersion in aqueous systems, and were highly selective and sensitive to the antibiotic metronidazole (MNZ) with low limit of detection (LOD: 0.10 μM), thus providing a new and promising fluorescent sensor for rapid detection of MNZ in aqueous solution.

A multiresponsive luminescent probe of antibiotics, pesticides, Fe3+ and ascorbic acid with a Cadmium(II) metal-organic framework

A novel two-dimensional (2D) cadmium-based metal-organic framework [Cd2(HDDB)(bimpy)(NMP)(H2O)]·3H2O (1) (H5DDB = 3,5-di(2′,4′-dicarboxylphenyl)benozoic acid and bimpy = 3,5-bis(1-imidazolyl)pyridine) has been constructed by solvothermal method, which exhibits good water stability, pH stability and excellent photoluminescence properties. Complex 1 reveals a fluorescence turn-off behaviour towards nitrofuran/nitroimidazole antibiotics and DCN pesticide due to PET (photoinduced electron transfer) and FRET (fluorescence resonance energy transfer). Interestingly, complex 1 can be designed as an “on-off-on” fluorescence probe to detect Fe3+ ion and ascorbic acid (AA). The fluorescence of complex 1 can be quenched by Fe3+ ion to form a Fe3+@1 hybrid system, which can be ascribed to the FRET process and the week interaction between Fe3+ and 1. Then, after gradually adding AA into Fe3+@1 system, the fluorescence intensity of Fe3+@1 fluorescence-silent system was recovered (turn on). The possible fluorescence turn-on mechanism is the elimination of FRET process between Fe3+ and complex 1. This work represents the first example of recognition of nitrofuran/nitroimidazole antibiotics, DCN pesticide, Fe3+ ion and AA based on a MOF material in aqueous solution.

A high-flux P84 polyimide mixed matrix membranes incorporated with cadmium-based metal organic frameworks for enhanced simultaneous dyes removal: Response surface methodology

The water sources contaminated by toxic dyes would pose a serious problem for public health. In view of this, the development of a simple yet effective method for removing dyes from industrial effluent has attracted interest from researchers. In the present work, flat sheet mixed matrix membranes (MMMs) with different physiochemical properties were fabricated by blending P84 polyimide with different concentrations of cadmium-based metal organic frameworks (MOF-2(Cd)). The resultant membranes were then used for simultaneous removal of eosin y (EY), sunset yellow (SY) and methylene blue (MB) under various process conditions. The findings indicated that the membranes could achieve high water permeability (117.8–171.4 L/m2.h.bar) and promising rejection for simultaneous dyes removal, recording value of 99.9%, 81.2% and 68.4% for MB, EY and SY, respectively. When 0.2 wt% MOF-2(Cd) was incorporated into the membrane matrix, the membrane separation efficiency was improved by 110.2% and 213.3% for EY and SY removal, respectively when compared with the pristine membrane. In addition, the optimization and modeling of membrane permeate flux and dye rejection was explored using response surface methodology. The actual and model results are in good agreement with R2 of at least 0.9983 for dye rejection and permeate flux. The high flux of the developed MMMs coupled with effective separation of dyes suggests a promising prospect of using P84 polyimide MMMs incorporated with MOF-2(Cd) for water purification.

Correction to “Combining Polycarboxylate and Bipyridyl-like Ligands in the Design of Luminescent Zinc and Cadmium Based Metal–Organic Frameworks”

ADVERTISEMENT RETURN TO ISSUEPREVAdditions and Correc...Additions and CorrectionsNEXTORIGINAL ARTICLEThis notice is a correctionCorrection to “Combining Polycarboxylate and Bipyridyl-like Ligands in the Design of Luminescent Zinc and Cadmium Based Metal–Organic Frameworks”Jose M. SecoJose M. SecoMore by Jose M. Seco, Sonia Pérez-YáñezSonia Pérez-YáñezMore by Sonia Pérez-Yáñez, David BrionesDavid BrionesMore by David Briones, José Ángel GarcíaJosé Ángel GarcíaMore by José Ángel García, Javier Cepeda*Javier CepedaMore by Javier Cepedahttp://orcid.org/0000-0002-0147-1360, and Antonio Rodríguez-Diéguez*Antonio Rodríguez-DiéguezMore by Antonio Rodríguez-Diéguezhttp://orcid.org/0000-0003-3198-5378Cite this: Cryst. Growth Des. 2019, 19, 11, 6823Publication Date (Web):October 7, 2019Publication History Published online7 October 2019Published inissue 6 November 2019https://doi.org/10.1021/acs.cgd.9b01278Copyright © 2019 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views467Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (230 KB) Get e-AlertsSUBJECTS:Crystal structure,Crystallography,Group theory,Ligand design,Ligands Get e-Alerts

Visible-Light-Responsive 2D Cadmium-Organic Framework Single Crystals with Dual Functions of Water Reduction and Oxidation.

The development of new metal-organic frameworks (MOFs) with dual functions of both water reduction and oxidation under visible-light irradiation is highly desirable for promising solar water splitting, but is not yet reported. Herein, a cadmium-based MOF (denoted as "Cd-TBAPy") single crystal with a 2D layered framework by employing 1,3,6,8-tetrakis(p-benzoic acid)pyrene (H4 TBAPy) as an organic linker is reported, which exhibits good visible-light absorption with edge of ≈600 nm. The Mott-Schottky (M-S) measurement and UV-vis analysis integrally reveal that the Cd-TBAPy is an n-type semiconductor with a bandgap of ≈2.15 eV whose conduction and valence band are estimated to be -0.05 and 2.10 eV, respectively. Together with loading of Pt or CoPi cocatalyst, the Cd-TBAPy is active for both water reduction and oxidation in the presence of scavengers under visible-light irradiation. Especially, the optimized apparent quantum efficiency for O2 evolution reaches 5.6% at 420 nm, much higher than that of previous MOF-based photocatalysts reported so far. This is thought to be the first MOF that functions as a photocatalyst for both water reduction and oxidation under visible light, demonstrating the intriguing future of MOF materials in solar-to-chemical energy conversion.