Based on one viologen carboxylate ligand 1,1’-bis(3-carboxylatobenzyl)-4,4’-bipyridinium) dichloride ([H2Cpzbpy]Cl2), three viologen-based coordination polymers were successfully synthesized by introducing three highly symmetric rigid carboxylate ligands. These polymers not only exhibit distinct structural characteristics but also demonstrate certain correlations in photochromic efficiency and photocatalytic oxidation of sulfides to sulfoxides. Specifically, CdCP-1 and CdCP-2 achieved 99 % yield and selectivity for sulfoxide production, demonstrating excellent scalability across multiple substrates. Furthermore, leveraging their outstanding reversible photochromic properties, these compounds were applied to information encryption and QR codes anti-counterfeiting.

Efficient adsorbents for organic dyes and iodine capture are critical to mitigate environmental hazards and safeguard public health. Herein, two structurally robust lanthanide MOFs (LCUH-126 and LCUH-127) were solvothermally synthesized with anthracene-based dicarboxylate ligands. Both samples adopt 2D layered structures, which further assemble into 3D supramolecular networks through intermolecular π···π stacking interactions of anthracene moieties, endowing the materials with prominent chemical and thermal stability. The large conjugated π-systems of anthracene together with interlayer -NH- groups endow the two MOFs with excellent adsorption capacity toward organic dyes and iodine. Abundant active sites originating from conjugated skeletons, -NH- moieties and coordinated solvent molecules strengthen the intermolecular interactions between iodine guests and the framework, affording high iodine vapor uptakes of 1.68 and 2.18 g/g at 80 °C. Appropriate interlayer spacing and hydrogen-bonding environments further favor the intercalation of dye molecules and the formation of weak intermolecular interactions. The two MOFs exhibit high adsorption capacities toward methylene blue (MB) and rhodamine B(RhB), and realize selective separation of mixed dye systems driven by electrostatic interaction and size matching. Combined with GCMC simulations, the adsorption mechanisms were elucidated. This work offers a rational strategy and theoretical basis for developing dual-functional adsorbents toward dye and iodine remediation.

Lanthanide-based metal-organic frameworks (MOFs) have emerged as promising sensing platforms, attracting significant research interest due to their potential for high-performance detection, with applications in biological and food systems. In this work, a novel and robust MOF (La-CIP) was fabricated through the coordination self-assembly of La(III) cations with flexible organic linkers. This framework demonstrates pronounced luminescence and functions as a dual-response fluorescent probe, enabling the selective and sensitive identification of guanosine and arginine via distinct signal modulation mechanisms-"turn-on" and "turn-off" fluorescence responses, respectively-amid competing RNA constituents and amino acids. The corresponding Stern-Volmer constants (Ksv) were determined to be 3.65 × 102 M-1 for guanosine and 2.09 × 104 M-1 for arginine, with detection limits as low as 69.3 μM and 0.65 μM, respectively. Furthermore, the underlying sensing mechanisms were elucidated using density functional theory (DFT) simulations.

With the escalating climate crisis caused by uncontrolled CO2 emissions, technological breakthroughs in CO2 capture and utilization have become imperative. Among these, photothermal catalysis, which utilizes full-spectrum to deliver necessary thermal input alongside photogenerated charge carriers, stands out by overcoming the high-temperature requirements of thermal catalysis and enhancing reaction kinetics. Composite metal oxides (CMOs) emerge as pivotal catalysts for photothermal CO2 hydrogenation toward valuable C1 products, leveraging tunable electronic structures and abundant oxygen vacancies that facilitate CO2 activation and H2 dissociation, while multi-phase interfaces promote synergistic electron transfer that refines selective pathways. Despite the rapid development of CMOs in photothermal CO2 hydrogenation in recent years, the research remains fragmented and lacks a systematic consolidation. This review delineates synthesis strategies for composite metal oxide catalysts, categorically examines recent advancements in application for converting CO2 into valuable C1 products, and elaborates on the mechanisms of reverse wateru2013gas shift (RWGS), methanation, and methanol synthesis pathways. Finally, we consolidate these insights to look ahead, addressing persistent challenges and strategic opportunities.

A highly stable heterometallic metal-organic framework (MOF), {[KCd(HL)]·DMF} (H4L = 2,5-di(2",4"-dicarboxyphenyl)-1,4-difluoro-benzene), denoted as LCU-118 (LCU = Liaocheng University), was successfully synthesized via a solvothermal approach. Aqueous suspensions of LCU-118 exhibit remarkable photoluminescent discoloration upon continuous ultraviolet (UV) irradiation. Moreover, LCU-118 demonstrates the efficient detection of nitrofurantoin (NFT) and nitrofurazone (NZF) through a fluorescence quenching mechanism. Interestingly, the fluorescence quenched by NFT can be recovered to some extent after UV irradiation, which provides a reliable method for distinguishing NFT from NZF. Additionally, LCU-118 displays excellent catalytic activity toward the oxidation of methyl phenyl sulfide (MPS) at room temperature, offering a novel strategy for the efficient utilization of green energy. Mechanistic investigations reveal that the generation of superoxide radicals in the suspensions is involved in endowing LCU-118 with such multifunctional properties..

The detection and removal of heavy metal ions and organic dyes in wastewater are crucial yet highly challenging. Herein, we report a stable terbium-based metal-organic framework, LCUH-125, assembled from Tb3+ ions and an anthracene-containing aromatic carboxylic acid ligand. LCUH-125 features a two-dimensional layered structure further extended into a three-dimensional supramolecular network through anthracene π···π stacking, with an interlayer spacing of 6.0-6.34 Å. This structure provides abundant π···π and C-H···π interactions, enabling efficient adsorption of methylene blue (MB, 528.1 mg·g-1) and rhodamine B (RhB, 147.8 mg·g-1) and selective separation of MB/methyl orange and RhB/methyl orange mixtures. Benefiting from excellent luminescence and water stability, LCUH-125 serves as a highly selective and sensitive multiresponsive luminescent sensor for Fe3+, Cr3+, Al3+, and Cr2O72- in aqueous solution with high Stern-Volmer constants. The adsorption and sensing mechanisms were systematically elucidated by characterizations and theoretical calculations. This work offers a valuable strategy for designing dual-functional MOF materials for wastewater treatment and luminescent sensing.

The environmental accumulation of nitrofuran antibiotics, exemplified by nitrofurazone (NZF), poses significant risks to ecosystems and public health, necessitating sensitive and rapid detection methods. Herein, we report a cadmium-based metal-organic framework (Cd-MOF) featuring a 2D → 3D interpenetrated structure and a noncoordinating N-containing ligand within its pores. This MOF acts as a selective fluorescence-quenching sensor for nitrofurazone (NZF) with a detection limit of 1.19 μM among other nitrofuran derivatives. By exploiting a ligand-substitution strategy, we exchanged the free ligand with the fluorescent aniline dye molecule to construct a dual-emission composite, DSM@Cd-MOF. This postsynthetic engineering fundamentally transforms the sensing response from quenching to a distinct ratiometric fluorescence enhancement, achieving a significantly lower detection limit (0.30 μM) and enabling clear visual discrimination. Both sensors demonstrate high reliability in real water samples, with recovery rates of 97.1-102.1%. This study establishes ligand-substitution as a powerful and generalizable strategy for tailoring the functionality of MOF-based sensors, providing an effective platform for monitoring antibiotic pollutants in environmental and biomedical settings.

Achieving highly selective adsorption and catalytic conversion of environmental pollutants, such as dyes and toxic chemical warfare agents, is of paramount importance. However, designing and synthesizing an ideal material capable of coupling these two processes within a single system remains a significant challenge. Herein, we have synthesized a trinuclear cadmium-based MOF (Cd-ACC), and its hierarchical porous structure facilitates the exposure of accessible active sites, thereby enabling the highly selective and rapid removal of eosin B (EB) with an impressive adsorption capacity. The experiments and theoretical studies have demonstrated that a dyeinduced in-situ exfoliation of Cd-ACC into a 2D nanosheet has occurred during the adsorption process, which has been affirmed by density functional theory (DFT) calculations. Notably, the composite material (EB@MOF), fabricated via a post-dye adsorption method, exhibits remarkable photoelectron transfer efficiency, thereby acquiring visible-light responsive characteristics. Consequently, EB@MOF triggers the generation of singlet oxygen (1O2) and superoxide radical (O2 center dot-) reactive oxygen species under ambient conditions and visible-whitelight irradiation, which exhibits efficient heterogeneous catalytic performance in the oxidation of 2-chloroethyl ethyl sulfide, achieving a high yield and selectivity. This work not only highlights a new strategy for the construction of crystalline framework nanosheets but also realizes white-light-driven oxidation of sulfides using this type of material as a catalyst.

With the escalating complexity of composite contamination in industrial wastewater, exploring high-efficiency and robust photocatalysts has become a research hotspot in environmental remediation. Herein, five isostructural rare-earth metal-organic frameworks (RE-MOFs, LCUH-128-132) were solvothermally assembled via the coordination of anthracene chromophore ligand 9,10-anthracenedicarboxylic acid (H2ADC) with five rare-earth metal ions (RE = Y, Eu, Gd, Tb, Dy). Remarkably, LCUH-129 (Eu-MOF) presents outstanding multifunctional photocatalytic activity without any additional photosensitizers or cocatalysts. It delivers a Cr(VI) reduction rate constant of 0.49 min-1, along with RhB and MB degradation rate constants of 0.23 min-1 and 0.026 min-1, respectively. The anthracene moiety serves as a light antenna to efficiently capture visible light; photogenerated electrons are rapidly transferred to rare-earth catalytic centers via ligand-to-metal charge transfer, which effectively inhibits electron-hole recombination. Radical trapping experiments and EPR characterization verify that ·OH, ·O2- radicals, and photogenerated electrons dominate the pollutant elimination processes. Furthermore, LCUH-129 exhibits excellent recyclability. This work affords a facile strategy for fabricating high-performance RE-MOF photocatalysts and reveals their promising prospects in the practical remediation of water composite pollution.

Luminescent metal-organic frameworks (MOFs) with multifunctional capabilities are highly sought after for applications in security, forensics, and environmental monitoring. Herein, a 2D Zn-MOF (LCU-133) was rationally constructed to integrate multiple functions based on intrinsic fluorescence and host-guest interaction. The intrinsic blue emission of LCU-133 enables high-resolution latent fingerprints imaging on multiple substrates, while its structural adaptability facilitates advanced information encryption via UV-responsive QR codes and anti-counterfeiting inks. Furthermore, LCU-133 demonstrates excellent fluorescence enhancement detection of ciprofloxacin (CIP) in river water, achieving low detection limits (LODs) of 0.56 and 0.25 µmol/L, respectively, with high selectivity, fast response and strong anti-interference ability. In addition, using a smartphone RGB app to analyze the luminous test strips, a naked eye on-site visual quantification detection CIP is realized. Comprehensive experiments coupled with DFT calculations elucidate a photoinduced electron transfer (PET)-mediated luminescence enhancement mechanism, underscoring the role of host-guest interactions in selective recognition. This work presents a versatile single MOF-based platform that bridges diverse luminescence applications in security, forensics, and environmental sensing.

Metal-organic frameworks (MOFs) attract wide interest for proton exchange membranes (PEMs) owing to structural tunability and proton-conducting capability. Nevertheless, how MOF-filler hydrophilicity governs proton conductivity and optimal doping loading in Nafion composites is insufficiently understood. Herein, three Nd-based MOFs with varied hydrophilicity are synthesized: one 3D Nd-L1 and two 2D layered Nd-L2 and Nd-L3. Nd-L3 possesses the highest surface hydrophilicity despite limited hydrophilic groups, originating from evenly distributed coordinated water on its 2D layers. Within the Nafion matrix, composite-membrane proton conductivity positively follows MOF hydrophilicity. Under 363 K and 100% RH, Nd-L3/Nafion-0.3% delivers 0.261 S cm-1, 1.89-fold higher than pure Nafion. Conversely, the optimal doping content correlates negatively with hydrophilicity; the highly hydrophilic Nd-L3 is prone to aggregation, leading to the lowest optimal doping content. The structure-property relationship analysis indicates that 2D layered structures facilitate the exposure of hydrophilic sites on the surface, effectively constructing continuous hydrogen-bonding networks that promote proton conduction. This work elucidates the critical role of MOF hydrophilicity in balancing proton conductivity and filler dispersion, offering a new strategy for designing high-performance PEMs.

Tetracyclines (TCs), widely used in livestock farming, accumulate in ecosystems and pose health risks due to their persistence. Existing detection methods suffer from high cost, complex procedures, and insufficient specificity. Herein, a dual-emission fluorescent composite (CDs@ZIF-8) was designed by encapsulating carbon dots (CDs) into zeolitic imidazolate framework-8 (ZIF-8). The composite material exhibits distinct dual emission peaks at 332 nm (ZIF-8) and 492 nm (CDs), and achieves ratiometric fluorescence sensing and differentiation between two structurally analogous antibiotics tetracycline (TC) and chlortetracycline (CTC) by quenching the ZIF-8 peak and enhancing the CD peak. The sensor achieves low detection limits of 7.13 nM for TC and 7.25 nM for CTC, with excellent selectivity and anti-interference capability over other antibiotics. A colorimetric logic gate and smartphone-based RGB analysis platform were developed for visual discrimination and quantitative detection, demonstrating high accuracy in real-sample analysis. This work provides a robust, low-cost strategy for on-site monitoring of TC antibiotics.

Heavy metal pollution, particularly from Fe3+, poses significant environmental and health risks, necessitating sensitive and selective detection methods. This study presents two amide-functionalized coordination polymers (CPs), Zn-CP and Cd-CP, designed for efficient Fe3+ sensing in aqueous media. Both CPs exhibit remarkable fluorescence quenching selectivity toward Fe3+ due to rich amide functional sites for enhancing sensing capability, achieving low detection limits (LODs) of 3.92/3.35 mu M in H2O and 5.14/4.84 mu M in HEPES buffer, surpassing the World Health Organization (WHO) and United States Environmental Protection Agency (USEPA) drinking water standard (5.36 mu M). The sensors demonstrate excellent selectivity, anti-interference capability, recyclability, and practical applicability through portable test strips for rapid visual detection. Multiple experiments co-reveal that fluorescence quenching mechanism arises from competitive energy absorption induced by weak interactions between Fe3+ and the N/O-active sites of the amide-decorated frameworks. This work highlights the potential of ligand-engineered CPs for environmental monitoring, offering a robust platform for heavy metal detection with high sensitivity and practical applicability.

Capturing CO2 from natural gas and flue gas is of critical importance for energy conservation and achieving carbon-neutrality goals, yet it remains a significant challenge. Herein, we report two novel and stable 3D lanthanide MOFs, LCUH-123 and LCUH-124, which demonstrate remarkably selective CO2 adsorption over CH4 and N2, exhibiting excellent separation performance for both CO2/CH4 and CO2/N2 gas mixtures. LCUH-123's channel is obstructed by two coordinated DMF molecules, leading to near-complete blockage and a significantly reduced adsorption capacity. In contrast, LCUH-124's micropores are enriched with H2O-coordinated sites and free [(CH3)2NH2]+ cations, enabling superior gas adsorption and separation performance. Compared to LCUH-123, LCUH-124 exhibits significantly improved gas adsorption and separation performance, achieving higher selectivity coefficients for CO2/N2 and CO2/CH4 at zero coverage. Breakthrough experiments confirm that LCUH-124 serves as an efficient adsorbent for high-purity separation of CH4 and N2 from binary CO2/CH4 and CO2/N2 mixtures. Furthermore, its cost-effective synthetic process offers substantial economic advantages for large-scale applications. Theoretical calculations have elucidated the distinct adsorption and separation mechanisms of CO2/CH4 and CO2/N2 mixtures in LCUH-124. The exceptional performance of LCUH-124 stems from its rationally engineered pore architecture and cavity-directed coordination of water molecules with [NH2(CH3)2]+ cations within the channel.

Transition metal sulfides (TMSs) have gradually become the major catalysts for bifunctional electrocatalytic processes of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) applied in rechargeable Zn-air batteries (ZABs). In this article, by epitaxially growing a Ni complex onto Co-based ZIF-67 as a precursor, an optimal catalyst (abbr. Co9S8/Ni3S2@NC-800) incorporating N-doped carbon matrices encapsulated binary Co9S8 and Ni3S2 nanoparticles was constructed by high-temperature pyrolysis, which can efficiently drive bifunctional ORR/OER activity (Delta E = 0.62 V). Notably, the catalyst exhibits remarkable 4e- ORR activity, characterized by a high half-wave potential (E 1/2 = 0.96 V), exceeding the performance of benchmark Pt/C. It demonstrates commendable OER activity, requiring a modest operating overpotential of only 325 mV (E J=10). Moreover, a ZAB assembled with Co9S8/Ni3S2@NC-800 as the air cathode has a substantial power density (213.17 mWcm-2), an elevated specific capacity (771.10 mAhgZn -1), and exceptional cycle stability (1421 h, 2842 cycles), which is potentially applied in various energy-related devices. The favorable ORR/OER performance may be due to the synergistic interaction of the N-doped carbon matrix and binary Co9S8 and Ni3S2 TMSs in the catalyst.

Antimony-based low-dimensional inorganic-organic hybrid metal halides are potential candidates for ecofriendly solid-state luminescent material due to their broad color gamut, strong oxidative resistance, and environmental compatibility. However, achieving deep-blue emission remains challenging due to strong electron-phonon coupling, which leads to self-trapped exciton formation and red-shifted emission. Here, we propose a novel mixed-cation engineering strategy by incorporating the aromatic cation (Amtz)+ (2-amino-4-methyl-1,3thiazol-3-ium) into the non-emissive indirect band gap material (DMA)3Sb2Cl9 (DMA = dimethylammonium). This approach transforms the material into a direct band gap semiconductor, (Amtz)2(DMA)Sb2Cl9, which exhibits narrow-band deep-blue emission at 400 nm with a full width at half maximum (FWHM) of 53 nm. The calculated CIE coordinates (0.15, 0.03) closely match the stringent BT.2020 standard (0.131, 0.046), demonstrating its potential for high-quality blue-emitting applications. Structural and theoretical analyses reveal that the rigid (Amtz)+ cation enhances lattice rigidity, suppresses electron-phonon coupling, and promotes free exciton emission. This work highlights the potential of mixed-cation engineering in tuning excitonic behavior for deep-blue emission and provides a new pathway for designing eco-friendly luminescent materials.

Reasonable design of metal-organic frameworks (MOFs) with multifunction pore environment and anionic structure for proton conduction and dye adsorption has important application value. Herein, we report two novel and stable isomorphic three-dimensional (3D) lanthanide metal-organic frameworks (LCUH-121 and LCUH-122). Both MOFs have unique pore sizes, which are respectively made up of smaller proton-conducting channels (LCUH-121: 6.8 × 11.4 Å2, LCUH-122: 6.1 × 11.4 Å2) and larger dye adsorption cavities (LCUH-121: 10.2 × 11.4 Å2, LCUH-122: 10.1 × 11.4 Å2). Remarkably, the high-density dimethylamine cations ([(CH3)2NH2]+) in the one-dimensional channel also endow them with dual functions, exhibiting both efficient proton conduction pathways and excellent cationic dye adsorption performance. The abundance of dimethylamine cations and the special environment of small pores give LCUH-121 and LCUH-122 proton conductivity (σ) values as high as 1.62 × 10-2 and 1.46 × 10-2 S·cm-1 (80 °C, 100% RH), which is the highest reported anionic MOFs to date. Meanwhile, the synergistic effect of the optimal large pore size and anion framework resulted in adsorption capacities of 1.23 and 1.20 g·g-1 for methylene blue (MB) by LCUH-121 and LCUH-122, respectively, and exhibited record-breaking adsorption rate constants (0.0698 and 0.0662 g·mg-1·min-1). More importantly, the Grand Canonical Monte Carlo (GCMC) elucidated that the proton conduction mechanism and dye adsorption mechanism mainly rely on a unique size dual pathway mechanism, in which protons are conducted through the small-pore framework and dye molecules are accommodated in a large pore framework.

C51H41N5O5S2Cd, triclinic, P (1) over bar (no. 2), a = 10.8410(9)angstrom, b = 13.0458(11)angstrom, c = 17.4971(15)angstrom, alpha = 68.8880(10)degrees, beta = 72.7460(10)degrees, gamma = 85.661(2)degrees, V = 2203.3(3)angstrom(3), Z = 2, R-gt(F) = 0.0655, wR(ref)(F-2) = 0.1765, T = 298(2)K.

Dual active center catalysts (DACs) are effective for accelerating the sluggish kinetics of cathodic oxygen reduction reaction (ORR) in rechargeable zinc-air batteries (ZABs). However, their tendency to aggregate severely restrict the catalytic efficiency. Herein, a "dual spatial confinement" route is conceived to develop a family of well-dispersed DACs for boosting ORR activity and ZABs. During pyrolysis, the Zn vacancies generated from Zn-Zeolitic imidazolate framework (Zn-ZIF) precursors facilitate the initial incorporation and confinement of Fe/Co atoms, enabling the formation of uniformly dispersed metal sites. Subsequently, the in-situ grown N-doped carbon nanotubes (CNTs) further regulate the dual active centers (Co3Fe7 and Co5.47N), ultimately yielding a highly efficient ORR catalyst. Owing to the synergistic effect between the dual active centers, the optimized Co3Fe7/Co5.47N@CNT-900 catalyst exhibits superior 4e- ORR activity. Theoretical calculations demystify that the Co3Fe7/Co5.47N sites co-promote the generation of OH- on Co centers, greatly enhance the ORR activity. When applied in rechargeable ZABs, the catalyst delivers a high power density of 168.99 mW cm-2, a high specific capacity of 904.57 mAh gZn -1, and good cycling stability, along with fine rate capability. This work shall light a pathway towards dual active center catalysts with sterling ORR activity.

Designing efficient photocatalysts for the reduction of hexavalent chromium (Cr(VI)) in wastewater was crucial but challenging. Herein, a nanoscale CdS@Ho-MOF photocatalyst composite was successfully synthesized by the anchoring of CdS quantum dots within the curved channels of Ho-MOF. The nanocomposite CdS@Ho-MOF-43.66% demonstrated outstanding performance, efficiently and swiftly photocatalyzing Cr(VI) to Cr(III) in aqueous solutions, which solely utilized water as the electron donor, eliminating the need for additional photosensitizers or cocatalysts. Under visible light irradiation and acidic conditions, CdS@Ho-MOF-43.66% showed a high rate constant (k) of 1.39 min-1, a fast reduction rate of 12.41 mg Cr(VI) g-1 cata min-1, and a superior reaction efficiency of 99%. The composite material demonstrated a 5-fold and 11-fold enhancement in reaction rate compared to pure CdS quantum dots and Ho-MOF, respectively, highlighting its synergistic catalytic superiority. Impressively, the prominent performance remained remarkably consistent even after undergoing seven cycles. The formation of an indirect Z-scheme heterojunction between CdS and Ho-MOF within the nanocomposite predominantly accounted for the elevated photocatalytic performance, which enhanced the separation efficiency of photogenerated charge carriers. This study provided an avenue for the development of cost-effective and high-performance photothermal catalysts for the catalytic reduction of Cr(VI).