A series of pyridinium-based ionic liquids (ILs) functionalized with soft (-SH) and hard (-OH, -COOH) donor groups were synthesized and characterized using high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), nuclear magnetic resonance (NMR) spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and ultraviolet-visible (UV-Vis) spectroscopy. All these spectroscopic techniques suggested the successful synthesis of the functionalized ILs. The iodine adsorption capacity experiments were performed to check the impact of soft and hard donors. The results show that these functionalized ILs have an excellent iodine adsorption capacity from 2.72 to 3.5 g center dot g-1 under 348 K and ambient pressure conditions. The ILs containing soft donors exhibited significantly higher iodine adsorption capacity compared to those containing hard donors, aligning with the principle where soft-soft interactions enhanced adsorption efficiency. The adsorbed iodine in ILs can be rapidly released into hexane and the recovered ILs can be reused multiple times to evaluate their iodine adsorption capacity, demonstrating excellent recyclability. The outstanding iodine capacity may be due to hydrogen bonding, polar interactions, and soft-soft interaction by-SH and-OH,-COOH sites in functionalized ILs. This suggests that the synthesized ILs are environmentally friendly, highly active, and suitable for utilization in the adsorption of iodine.

Aqueous zinc-iodine (Zn-I2) batteries demonstrate promising potential for large-scale energy storage applications. However, the uncontrolled "shuttle effect" of polyiodides (I3 -, I5 -) results in capacity loss, lower Coulombic efficiency (CE), and poor cycling reversibility. Herein, we propose alkyne-rich covalent organic frameworks (COFs) as functional separator coatings to effectively suppress the "shuttle effect", establishing a protective solid electrolyte interphase (SEI) layer to stabilize the Zn metal anode. The effect of different alkyne contents in COFs on the performance of Zn-I2 batteries is investigated, and the results demonstrate that increasing alkyne content significantly improves CE, ion migration rate, and cycling stability. Remarkably, the 100% alkyne-functionalized TAPT-BPTA-COF separator exhibited excellent ion selectivity, effectively blocking the diffusion of polyiodide species, while favoring the transport of Zn2+. This selective transport ensures uniform deposition of Zn2+ on the anode during cycles, thereby reducing internal resistance and improving cycle performance. Notably, the Zn||TAPT-BPTA-COF||I2 battery delivers an initial capacity of 8.4 mAh cm-2 at 20 mA cm-2, retaining 70.1% of the initial capacity over 1200 cycles with 99% CE. Complementary spectroscopic analyses and visualization experiments further confirm that the fully alkyne-conjugated electronic structure of COFs enhances electrical conductivity. This study provides a molecular design strategy for developing high-performance, COF-based electrochemical materials for Zn-I2 battery systems.

The separation of acetylene (C2H2) from carbon dioxide (CO2) and its subsequent storage remain formidable challenges in the petrochemical industry due to their nearly identical kinetic diameters and similar physical properties, which render conventional adsorption methods inefficient. Herein, we report an anion-pillared ultra-microporous metal-organic framework, Ni-TiF6-T4PP, engineered with tailored pore geometry and selective binding sites to achieve efficient C2H2/CO2 separation. This material exhibits a high C2H2 uptake of 3.99 mmol g(-1) at 298 K and 1 bar. The pore environment, enriched with nitrogen and fluorine sites, promotes host-guest interactions with C2H2, resulting in a substantial differential in the isosteric heats of adsorption (Q(st)): 36.04 kJ mol(-1) for C2H2 versus 19.35 kJ mol(-1) for CO2. Combined with its low regeneration energy barrier, the framework can be readily regenerated, contributing to its recyclability. Breakthrough experiments demonstrate achieves separation performance for equimolar C2H2/CO2 mixtures. At 353 K, a C2H2 mixture with an initial concentration of 90% can be purified to achieve a final purity of > 99.2%. Based on the combined evidence from in situ infrared spectroscopy and molecular simulation, the underlying gas adsorption mechanism has been conclusively established that the extended pi-surfaces of porphyrin and pyridine moieties enable multipoint cooperative binding with C2H2.

Aqueous zinc-iodine (Zn─I2) batteries are promising candidates for large-scale energy storage owing to their inherent safety, low cost, and high theoretical capacity. However, their practical application is hindered by the polyiodide shuttle effect, sluggish iodine redox kinetics, and uncontrolled zinc dendrite growth. Herein, we design a functional separator modified with metallophthalocyanine-based covalent organic frameworks (MPc-COFs, M═Co, Ni, Cu) to simultaneously regulate iodine electrochemistry and zinc deposition behavior. The optimized Gr@CoPc-COF@GF separator leverages a synergistic mechanism: atomically dispersed Co active sites strongly adsorb polyiodides to suppress shuttling while accelerating iodine redox kinetics, and the well-ordered CoPc-COF nanochannels facilitate uniform Zn2+ flux. As a result, the corresponding Zn─I2 battery delivers a high specific capacity of 208.6 mAh g-1 at 571 mA g-1 and achieves excellent capacity retention with 96.97% Coulombic efficiency after 48 h of open-circuit rest. This work presents a rational separator design strategy for high-performance Zn─I2 batteries, highlighting the importance of molecular-level engineering in advanced energy storage systems.

Developing high-efficiency adsorbents for the selective capture of thorium from uranium and rare earth elements necessitates integrating multiple critical functions, including strong adsorption ability, exceptional selectivity, and acid-resistance performance, posing a technically challenging task. Herein, guided by the hard-soft acid-base (HSAB) principle, a series of imine-linked covalent organic frameworks (COFs) functionalized by oxygen-rich groups is designed and synthesized. The abundance of high-affinity dual-active N and O sites on the COF skeleton enables rapid adsorption kinetics and superior Th(IV) uptake. Particularly, TPT-PA-COOH and TPT-PA-SO3H exhibit record-breaking saturated adsorption capacity and Th/U separation selectivity, making them the most efficient Th(IV) adsorbent reported to date. Especially, the introduction of -COOH or -SO3H groups renders the 2D COFs highly acid-resistant, while keeping good Th(IV) adsorption capacity and selectivity even under harsh acidic conditions. These findings provide insight into the coordination mechanism between thorium and functional binding sites, thus advancing applications of COFs in the separation of thorium from radioactive wastewater.

The development of efficient and selective catalysts for olefin hydrogenation is of paramount importance in chemical synthesis. Herein, we report a novel organic–inorganic hybrid polyoxometalate (POM), Na2H7[(FeII(phen)(H2O))4(FeIII(phen)(H2O)3)4(P2W15Nb3O62)4]-(FeIII(phen)4)2(phen)2·36H2O (denoted as Fe-POM), which was synthesized hydrothermally. Its structure comprises a unique tetrameric assembly where four mixed-addenda {P2W15Nb3} units are bridged by Fe-phen complexes. Leveraging its robust stability and capacity to function as an "electron reservoir", Fe-POM was employed as a support to immobilize Pd nanoparticles, yielding the composite catalyst Fe-POM/Pd. This composite exhibits exceptional performance in the hydrogenation of olefin derivatives, achieving >99 % conversion and >99 % selectivity for the C=C bond in 4-nitrostyrene within 30 min under ambient conditions (room temperature, 1 atm H2). Control experiments confirm that the synergy between Pd nanoparticles and the Fe-POM support is crucial for the observed high activity. Mechanistic studies reveal that the catalytic process involves hydrogen spillover from Pd to the POM framework, where Fe-POM acts as an effective electron and proton reservoir, facilitating the efficient hydrogenation reaction. This work highlights the potential of functionally designed POMs as advanced platforms for creating high-performance catalytic systems.

The support effect in platinum catalysts plays a decisive role in governing active-site dispersion and electronic structure, with direct implications for liquid organic hydrogen carrier (LOHC) technologies. Herein, we synthesized a series of Pt catalysts supported on TiO2, γ-Al2O3, and a binary TiO2-γ-Al2O3 to stabilize Pt single atoms and systematically evaluated their catalytic performance in the cyclohexane dehydrogenation to benzene and hydrogen. Structural, compositional and morphological analyses revealed that the binary TiO2-γ-Al2O3 support promotes the formation of highly dispersed and electronically modified Pt species, with a strong metal-support interaction (SMSI) arising from interfacial Ti–O–Al bonding. The catalytic performance of Pt/TiO2-γ-Al2O3 catalyst markedly outperformed its single-oxide counterparts, achieving a remarkable hydrogen production rate of 955 mmol/gPt/min at 295 °C and a WHSV of 9.36 h-1, with high benzene selectivity and stability. The superior performance can be attributed to the synergy between atomically dispersed Pt, the bifunctional mixed-oxide support, and SMSI-induced electronic modulation. This work provides valuable insights for the rational design of high-performance Pt catalysts for on-demand hydrogen production from LOHCs.

ABSTRACT Although covalent organic frameworks (COFs) have garnered significant attention as versatile scaffolds in photocatalysis, it is constrained by the sluggish charge‐carrier dissociation inherent to organic semiconductors. Moreover, how subtle changes in atomic topology within an otherwise similar framework translate into macroscopic optoelectronic behavior remains insufficiently understood. Herein, we demonstrate that precise nitrogen‐site isomerism within the framework backbone serves as a critical lever to manipulate exciton dynamics. By synthesizing two regioisomeric vinylene‐linked COFs, PzDA‐TMT‐COF (pyrazine‐based, para‐N) and DzDA‐TMT‐COF (pyridazine‐based, ortho‐N), we reveal that a subtle translocation of nitrogen atoms induces a profound divergence in charge‐separation efficiency. Despite identical chemical compositions and porosities, the para‐configured PzDA‐TMT‐COF delivers a significantly enhanced hydrogen evolution rate of 13.2 mmol g −1 h −1 , significantly outperforming its ortho‐analogue. It is elucidated that this “atomic editing” fundamentally reshapes the intramolecular potential landscape: the para‐substitution maximizes donor–acceptor polarization and minimizes exciton binding energy, thereby accelerating the transition from bound excitons to free charge carriers. Our findings establish a rigorous structure–activity relationship, highlighting that rational control over heteroatom placement is a paramount design principle for organic photocatalysts.

The development of separator by tunning the zincophilic and iodide ion-repulsive properties of covalent organic frameworks (COFs) that regulate cycle lifespan and capacity of aqueous zinc-iodine (Zn-I2) batteries is one of challenges. In this work, we have shown a systematic strategic-driven investigation to elucidate the role of functional triazine properties in COF modified separator towards overall performance of aqueous Zn-I2 batteries. As such, three COFs with the same topology but different triazine number in their structures, have been synthesized, among which the triazine-richest framework, TAPA-TTB-COF-based separator demonstrated to be most effective to guide uniform Zn2+ flux and simultaneously inhibit polyiodide shuttling due to the zincophilic nature and good iodide ion-repulsive capability of triazine. Consequently, the Zn||Gr@TAPA-TTB-COF@GF||Zn symmetric battery achieves a long life of more than 2100 h (5.0 mA cm-2) and the initial area capacity of the Zn||Gr@TAPA-TTB-COF@GF||I2 battery reaches up to 5.5 mAh cm-2 (20 mA cm-2). After 2000 cycles, the discharge capacity can still maintain at3.0 mAh cm-2 with a capacity decay rate of only 0.023 % per cycle. This study provides guidance for the rational design of functional COFs separators and promotes their application in high energy storage systems.

The construction of single-atom catalysts (SACs) using polyoxometalates (POMs) as supports has attracted significant attention. Specifically, POMs possess the unique ability to reversibly accept and donate electrons; yet, the potential benefits of this distinctive characteristic on the activity of single atoms have remained unexplored. In this study, we employ density functional theory (DFT) calculations to investigate the synthesis of CH3COOH from CO, CH4, and H2O catalyzed by POM-supported SAC M1/POM (M = Pt, Rh, Ru, Pd, Co), aiming to gain a more comprehensive understanding of the role of POM support in SACs. Our proposed mechanism first involves CH4 activation for producing •CH3 and, at the same time, the catalytic intermediate [M1/POM]-. Then, CO and •CH3 are sequentially adsorbed on the single-atom site of [M1/POM]- and coupled to form COCH3. Finally, as H2O attacks CH3CO, CH3COOH is formed and released. The poorer activity of M1/POM (M = Rh, Ru, Pd, Co) compared with that of Pt1/POM is attributed to the low matching degree in the frontier molecular orbital energy between [M1/POM]- and CO/•CH3, which results in the inaccessibility of CO and •CH3 adsorptions, thus hindering the subsequent CH3COOH formation. Throughout the reaction process, the POM support promotes dynamic switching of single atoms between electron-rich and electron-poor states, leveraging its reversible electron transfer capability. The electron-deficient species •CH3 adsorption and H2O attack are enabled by the regular access of single atoms to electron-saturated state, while timely switching of single atoms to electron-deficient states facilitates CO adsorption and CH3 attack.

The inherent sluggish kinetics of the conventional four-electron transfer pathway fundamentally limits the oxygen reduction reaction (ORR) efficiency. While electronic structure modulation offers potential solutions, developing effective catalytic regulation strategies remains challenging due to elusive structure-activity correlations. In this study, Fe4 cluster sites are engineered with dual parallel electron transfer channels that enable concurrent O─O bond cleavage and dual oxygen atom protonation. This unique configuration facilitates an optimized two-step double electron transfer mechanism, significantly enhancing ORR kinetics. Synergistic Mn single atom sites, strategically positioned as electron reservoirs, substantially elevate the electron density of Fe4 clusters while reinforcing Fe─N coordination bonds through charge redistribution. Remarkably, the spatial configuration of Fe4 clusters at the support periphery minimizes steric confinement effects, allowing simultaneous product desorption and oxygen adsorption - a critical advantage for sustaining continuous catalytic cycles. Through combined experimental and theoretical analyses, it is demonstrated that this dual-channel electron transport system effectively reduces activation barriers for elementary steps while accelerating charge transfer kinetics. This fundamental study establishes a new paradigm for designing high-performance ORR catalysts through multi-site collaborative engineering and reaction pathway optimization.

Compared with the most advanced lithium-ion batteries, aqueous zinc-iodine batteries (Zn-I2 batteries) have higher theoretical capacity and energy density, thus attracting much attention in energy storage. However, due to several technical issues, the commercialization of Zn-I2 batteries is still at a bottleneck, and among them, the "shuttle effect" of polyiodide anions is considered to be a main challenge. In order to minimize the shuttle of polyiodide species within the cathode compartment, we herein synthesize a zinc-ion conductive covalent organic framework (COF), namely DMSBA-Tp-COF, that is used to assemble a composite separator together with commercial glass fiber (GF) substrate and graphene (Gr) by a simple vacuum filtration coating technology. The negatively charged -SO3- ions present in COF coatings enable homogeneous Zn2+ flux and simultaneously suppress polyiodides shuttling in the Zn-I2 batteries. As a result, the composite Gr@DMSBA-TpCOF@GF separator endows the corresponding Zn-I2 symmetrical cell with excellent long-term cyclic stability with a lifespan over 800 h and high-specific capacity of 3.2 mAh cm-2 (at a current density of 20 mA cm-2, voltage range of 0.7-1.7 V). This study provides a prospective strategy to rationally design functional COFs separators and accelerate their applications in high energy storage systems. (c) 2025 Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Covalent organic frameworks (COFs) are commonly synthesized via solvothermal methods at high temperatures for more than 72 hours, utilizing hazardous organic solvents as reaction media. Here, we propose a methodology for the rapid (2-hour) synthesis of imine-linked and hydrazone-linked COFs in supercritical carbon dioxide (scCO2), thereby preventing most of the drawbacks of traditional solvothermal methods. The crystallinity and porosity of COFs synthesized in scCO2 (designated as scCO2-COFs) are comparable to or better than those obtained by traditional solvothermal approaches. Furthermore, the iodine adsorption capacity of these scCO2-COFs is analyzed. The results suggest that the synthesized scCO2-COFs have a remarkable iodine adsorption capacity in the range of 1.01 to 6.38 g g-1 at 75 degrees C under ambient pressure conditions. The adsorbed iodine in the scCO2-COFs can be rapidly released into methanol, and their exceptional iodine adsorption capacity can be maintained after five runs. The outcomes of this research could unlock new opportunities for designing and synthesizing scCO2-COFs, aimed at a broad range of environmental applications.

Rational design of covalent organic frameworks (COFs) at the molecular level is necessary to improve their photocatalytic hydrogen evolution (PHE) performance.

The design and synthesis of organic photocatalysts remain a great challenge due to their strict structural constraints. However, this could be mitigated by achieving structural flexibility by constructing permanent porosity into the materials. Conjugated microporous polymers (CMPs) are an emerging class of porous materials with an amorphous, three-dimensional network structure, which makes it possible to integrate the elaborate functional groups to enhance photocatalytic performance. Here, we report the synthesis of a novel CMP, named TAPFc-TFPPy-CMP, constructed by 1,1′3,3′-tetra(4-aminophenyl)ferrocene (TAPFc) and 1,3,6,8-tetrakis(4-formylphenyl)pyrene (TFPPy) monomers. The integration of the p-type dopant 7,7,8,8-tetracyanoquinodimethane (TCNQ) into the TAPFc-TFPPy-CMP improved the light adsorption performance, leading to a decrease in the optical bandgap from 2.00 to 1.43 eV. The doped CMP (TCNQ@TAPFc-TFPPy-CMP) exhibited promising catalytic activity in photocatalytic CO2 reduction under visible light, yielding 546.8 μmol g−1 h−1 of CO with a selectivity of 96% and 5.2 μmol g−1 h−1 of CH4. This represented an 80% increase in the CO yield compared to the maternal TAPFc-TFPPy-CMP. The steady-state photoluminescence (PL) and fluorescence lifetime (FL) measurements reveal faster carrier separation and transport after the doping. This study provides guidance for the development of organic photocatalysts for the utilization of renewable energy.

In view of the flue gas characteristics of cement kilns in China, the development of low-temperature denitrification catalysts with excellent anti-poisoning performance has important theoretical and practical significance. In this work, a series of MnCeOx@TiO2 and tourmaline-containing MnCeOx@TiO2-T catalysts was prepared using a chemical pre-deposition method. It was found that the MnCeOx@TiO2-T2 catalyst (containing 2% tourmaline) exhibited the best low-temperature NH3-selective catalytic reduction (NH3-SCR) performance, yielding 100% NOx conversion at 110 °C and above. When 100–300 ppm SO2 and 10 vol.% H2O were introduced to the reaction, the NOx conversion of the MnCeOx@TiO2-T2 catalyst was still higher than 90% at 170 °C, indicating good anti-poisoning performance. The addition of appropriate amounts of tourmaline can not only preferably expose the active {001} facets of TiO2 but also introduce the acidic SiO2 and Al2O3 components and increase the content of Mn4+ and Oα on the surface of the catalyst, all of which contribute to the enhancement of reaction activity of NH3-SCR and anti-poisoning performance. However, excess amounts of tourmaline led to the formation of dense surface of catalysts that suppressed the exposure of catalytic active sites, giving rise to the decrease in catalytic activity and anti-poisoning capability. Through an in situ DRIFTS study, it was found that the addition of appropriate amounts of tourmaline increased the number of Brønsted acid sites on the catalyst surface, which suppressed the adsorption of SO2 and thus inhibited the deposition of NH4HSO4 and (NH4)2HSO4 on the surface of the catalyst, thereby improving the NH3-SCR performance and anti-poisoning ability of the catalyst.

Photodynamic therapy (PDT) is an emerging treatment but often restricted by the availability of oxygen. Enhancing the lifespan of singlet oxygen (1O2) by fractionated generation is an effective approach to improve the efficacy of PDT. Herein, an imine-based nanoscale COF (TpDa-COF) has been synthesized and functionalized with a pyridone-derived structure (Py) to create a 1O2-storing nanoplatform TpDa-COF@Py, which can reversibly capture and release 1O2. Under 660 nm laser exposure, Py interacts with 1O2 produced by the porphyrin motif in COF backbones to generate 1O2-enriched COF (TpDa-COF@Py + hv), followed by the release of 1O2 through retro-Diels-Alder reactions at physiological temperatures. The continuous producing and releasing of 1O2 upon laser exposure leads to an "afterglow" effect and a prolonged 1O2 lifespan. In vitro cytotoxicity assays demonstrates that TpDa-COF@Py + hv exhibits an extremely low half-maximal inhibitory concentration (IC50) of 0.54 µg/mL on 4T1 cells. Remarkably, the Py-mediated TpDa-COF@Py nanoplatform demonstrates enhanced cell-killing capability under laser exposure, attributed to the sustained 1O2 cycling, compared to TpDa-COF alone. Further in vivo assessment highlights the potential of TpDa-COF@Py + hv as a promising strategy to enhance phototheronostics and achieve effective tumor regression. Accordingly, the study supplies a generalized 1O2 "afterglow" nanoplatform to improve the effectiveness of PDT.