Electrocatalytic oxidation of glycerol for value-added chemicals is a superior strategy to utilize the excess glycerol produced in the biodiesel industry. Pd is one of the few active catalysts for alkaline glycerol oxidation reaction (GOR); however, glycerol inevitably dissociates and converts to carbon dioxide on the Pd surface, which results in its low total Faradaic efficiency (FE) for high-value-added products. Herein, a series of Pd/C and Pd10Bix/C catalysts were synthesized to investigate the GOR pathway. The Pd10Bi3/C catalyst with optimal Bi content achieved an excellent GOR mass activity of 7.5 +/- 0.2 A mgPd -1 and an outstanding total FE of 90 %+/- 3 %, which are much higher than those values on Pd/C (1.2 +/- 0.2 A mgPd -1 for mass activity and 63 %+/- 4 % for total FE). Combined results of in-situ attenuated total reflection surface enhanced infrared absorption spectroscopy and density functional theory calculations show that Bi suppresses the dissociation of glycerol through the "shielding effect" of Bi to the adjacent Pd sites, which weakens the adsorption strength of GOR intermediates on those sites. This work provides a new insight into the GOR mechanism and puts forward a valid strategy for the rational design of catalysts to enable the transformation of glycerol into high-value-added products. (c) 2025 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Halogenated byproducts from the disinfection of domestic wastewater and drinking water are highly toxic in water environment. The multi-target and selective detection of halogenated byproducts is still a challenge due to their inherent similarity in molecular structures. Herein, we propose a multifunctional sensing platform for halogenated byproducts based on surfactant-induced clusteroluminescence. Apart from the blue emission (430 nm) from clustering-triggered luminescent histidine-modified cyclodextrin (CDHis), the molecular assembly in water or on gas-water interface induced by surfactant, i.e., cetyltrimethylammonium bromide (CTAB), triggers new green luminescence at 517 nm due to through-space conjugation (TSC) during self-assembly. With the multi-color CDHis·CTAB aggregate as the sensing element, hydrophobic trihalomethanes (THMs) can incorporate into the assembly and obstruct TSC with decreased green clusteroluminescence, while the hydrophilic trichloroacetic acid (TCA) with high affinity with histidine moiety could promote TSC with emerging red emission at 617 nm. This multifunctional sensing platform achieves ultrasensitive detection with LODs of 21 μg/L and 3.5 μg/L for total THMs and TCA, respectively. Visual and simultaneous detection of THMs and TCA under in situ ultrasound can be achieved through imaging analysis. This study presents a novel in situ sensing platform for multi-target and highly selective DBPs in water sample, which provides a new approach for trace DBPs detection based on aggregate science.

To address the risks of quinolone antibiotic pollution, rapid on-site monitoring is urgently needed to safeguard food safety and public health. In response, this study developed a portable multi-emission fluorescent hydrogel sensor, EuTbCa@HOFBTB-SC, for the detection of flumequine (FQ), norfloxacin (NOR), and ciprofloxacin (CIP). The sensor was fabricated via the in-situ embedding of lanthanide-functionalized hydrogen-bonded organic frameworks (HOFs) into the hydrogel network. This unique design integrates the stable reference signal of the HOFs, the specific response of lanthanide ions (Eu3+/Tb3+), and the enrichment capability of the hydrogel, enabling a highly sensitive ratiometric fluorescent detection. The analytes enhanced the green emission of Tb3+ via an "antenna" effect, while quenching the fluorescence of the HOFs due to an internal filtering effect (IFE), achieving detection limits as low as 0.053 mu M, 0.019 mu M, and 0.014 mu M for the three targets, respectively. The hydrogel matrix provides excellent physical stability and operational simplicity. Furthermore, due to the disruption of energy transfer between Tb3+ and Eu3+ in EuTbCa@HOFBTB-SC during sensing, the sensor exhibits a distinct red-to-green color transition under a 254 nm UV lamp, enabling visual screening and facilitating the on-site analysis of real samples. This work provides a powerful and portable sensing platform and offers advanced strategies for the development of next-generation sensors.

Passive miniature liquid fuel cells, which eliminate the need for external auxiliary power components, exhibit high system energy density and are considered ideal candidate power sources for portable electronics. However, due to the inherent absence of active purging and auxiliary drainage mechanisms, severe cathodic water flooding frequently occurs during high-current-density operation, leading to a dramatic surge in mass transport resistance and rapid performance degradation. To address this gas-liquid two-phase transport bottleneck, this study proposes a fully autonomous physical flow-remodeling strategy by constructing an asymmetric wettability gradient within the channels of the current collector. By depositing a hierarchical micro-nano superhydrophobic network on the membrane electrode assembly (MEA) side while maintaining weak hydrophobicity on the air-breathing side, an outward Young-Laplace capillary pumping force is spontaneously induced to autonomously expel liquid water in response to localized current loads. Experimental results demonstrate that this self-adaptive, directional capillary driving mechanism effectively unblocks the cathodic oxygen transport network without any parasitic power consumption. Under optimal feed concentration, the peak power density of the gradient configuration is enhanced by over 41% compared to the pristine substrate and 19% over the best-performing uniform treatment (PTFE). Furthermore, during a constant-current discharge test, this configuration eliminates potential oscillations caused by the periodic accumulation of water plugs, significantly retarding the physical degradation of interfacial components. The self-adaptive gas-liquid separation mechanism established in this study breaks the inherent engineering trade-off between passive drainage and Ohmic loss, providing a theoretical paradigm for the flow field structural design of next-generation highly efficient, fully self-sustained self-driven miniature energy systems.

Self-oxygenating H2O2 photosynthesis represents a promising strategy to effective groundwater disinfection for safe drinking, it is crucial to achieve spatially proximate redox dual sites with great challenge. Herein, sulfonylbridged perylene diimide polymer (SuPDI) nanorods with higher crystallinity are first synthesized via an imidazole solvent method, followed by functionalization with nearly contacted CoOx-polydopamine (PDA) dual sites, in which the photogenerated holes control the deposition of CoOx clusters, and the time-dependent polymerization introduces PDA oligomer fragments. The optimized photocatalyst exhibits state-of-the-art O2 evolution activity (18.2 mmol g-1 h-1), enabling efficient self-oxygenating H2O2 photosynthesis (70.0 mu mol g-1 h-1) under anoxic conditions, even achieving 55% of yield under exposed air. Femtosecond-transient absorption spectra and in situ X-ray photoelectron spectra reveal that exceptional activity is attributed to the outstanding O2-evolution SuPDI, and the effective Z-scheme charge transfer between PDA and SuPDI, and separated CoOx-PDA dual sites for facilitating hole-driven H2O oxidation and electron-mediated O2 reduction, respectively. Notably, nearly contacted dual sites are critical for enabling self-oxygenating H2O2 photosynthesis, as theoretical calculations reveal that such dual sites significantly lower the energy barrier for O2 diffusion toward the PDA. Significantly, this resulting photocatalyst displays exceptional antibacterial performance under anoxic and sunlight conditions, comparable to O2-saturated ones.

Carbon dioxide (CO2) separation and capture technologie have been considered as a viable strategy for mitigating CO2 emissions to reduce the greenhouse effect. Metal organic frameworks (MOFs)-based membrane separation technology has demonstrated to be an efficient and sustainable approach for CO2 separation and capture compared to the conventional methods. The development of high-performance materials and fabrication techniques, assisted with modern computational methods, has become an active research area. In this review, the state of the art and applications of MOFs-based membrane for CO2 separation technology were summarized, and the materials synthesis and modification methods reported in the last five years were comprehensively compared to evaluate the advantages and limitations in improving the permeability and selectivity of the membranes. The most recent progress of computational methods involving molecular simulations and machine learning was outlined to understand the underlying molecular mechanisms of the separation performance and high-throughput screening of materials. Finally, the challenges and prospects of the current development status of MOFs-based membranes in both experiments and data-driven methods for CO2 separation were addressed.

Photothermal catalysis offers a promising route for CO2 cycloaddition with epoxides, yet efficient charge utilization and mechanistic clarity remain challenging. Traditional thermal catalysis typically requires harsh conditions (high temperature and pressure) and suffers from low energy efficiency, while single photocatalysis is limited by rapid charge recombination and insufficient activation of inert CO2. Herein, we develop a photo-thermal dual-responsive catalyst, ZnNCN/NaK-CN, by integrating photo-active NaK-doped g-C3N4 with zinc cyanamide (ZnNCN). This catalyst achieves a high productivity of 147.3 mmol g-1 h-1 under full-spectrum illumination and delivers 84.8-99.4% yields for various cyclic carbonates, surpassing most recently reported catalysts and commercial benchmarks. Notably, the apparent activation energy is reduced from 40.9 kJ mol-1 (thermal-only) to 33.4 kJ mol-1 under photothermal conditions. Mechanistic studies reveal that CO2 preferentially adsorbs on the ZnNCN framework, and photogenerated electrons driven by the built-in electric field (BEF) transfer from NaK-CN to CO2 adsorbed on ZnNCN, forming highly reactive center dot CO2-radicals that accelerate the ring-closing step. This work not only presents a robust catalyst for photothermal CO2 conversion but also provides a mechanistic framework for photogenerated electron-mediated CO2 activation in cycloaddition reactions.

Developing multifunctional and super-wetting separation materials is of great significance for treating complex oily wastewater in real environment. Herein, the superhydrophilic Cu-HHTP@Cu foam with hierarchical structure was fabricated by chemical oxidation and in situ growth strategies, which showed an outstanding separation efficiency (>99.4 %) and flux (>92.1 kL center dot m(-2)center dot h(-1)) for various oil/water mixtures. The electrostatic attraction, pi - pi interactions and hydrogen bonding between Cu-HHTP@Cu foam and dyes facilitate the adsorption process, with a removal efficiency > 94.7 %. To absorb high-viscosity crude oil, the Cu-HHTP@Cu foam was further modified with polydimethylsiloxane (PDMS) to finally obtain superhydrophobic PDMS@Cu-HHTP@Cu foam, which demonstrates high separation efficiency (>99.8 %) and flux (>90.3 kL center dot m(-2)center dot h(-1)). Both Cu-HHTP@Cu foam and PDMS@Cu-HHTP@Cu foam also showed stable durability after 20-cycle tests. More importantly, due to the introduction of Cu-HHTP, PDMS@Cu-HHTP@Cu foam presented excellent photothermal conversion behavior with the surface temperature reaching up to 72.0degree celsius under simulated sunlight, which remarkably facilitate the cleaning of crude oil. This work shows that modified Cu foam is a promising candidate for absorbing dyes and treating crude oil spills and is expected to provide a convenient method for oil/water separation.

The ultrasensitive, visual and intelligent identification of persistent chlorophenols (CPs) in complex drinking and environmental water matrices is highly desirable. In this study, we have established an interesting colorimetric dye eosin Y (EY)-molecular imprinted Bi4O5Br2 nanosheet photosensitization sensing system for CPs detection, in which the key is the rapid EY photosensitization decolorization to be efficiently inhibited in the presence of CPs. It displays an ultrasensitive detection of CPs, especially for the typical 2,4,6-trichlorophenol (TCP) across from 10 ng·L-1 to 1 mg·L-1, achieving a limit of detection of 7 ng·L-1 with remarkable selectivity. By means of in-situ Fourier transform infrared spectroscopy, time-resolved laser flash photolysis spectroscopy, and theoretical calculations, the outstanding performance is attributed to (i) the efficient transfer of triplet excited state electrons from EY to the ultrathin Bi4O5Br2 (∼4 nm) nanosheets through energy band alignment and (ii) enhanced TCP selective adsorption resulting from a planar adsorption configuration induced by multiple Bi-Cl interactions, along with specific molecular imprinting recognition sites. Additionally, a real-time intelligent sensing platform was further engineered by integrating automatic sampling, an optical fiber source and a smartphone with color recognition software, enabling convenient and visual detection of TCP in challenging water environments. The sensing system exhibited excellent performance in detecting TCP across various actual water matrices, achieving acceptable recovery ranging from 93.33 % to 113.33 % with the relative standard deviations between 0.80 % and 11.31 %. It also demonstrated significant advantages over the ultra-performance liquid chromatography-tandem mass spectrometry, particularly regarding speed, simplicity and sensitivity, thus indicating substantial potential for practical applications in water quality monitoring.

How to improve the selectivity and stability while ensure the membrane permeability is a challenge of mixed matrix membranes (MMMs) for gas separation applications. We herein report an amine-functionalized COFsbased mixed-matrix membranes (MMMs) for CO2/N2 separation, specifically COF-300-Amide/Pebax2533. This approach endeavors to concurrently enhance the selectivity of CO2/N2 and stability while maintain the high permeability of CO2. The natural pore structure of amide-linked COFs significantly enhances the selectivity for CO2/N2 separation, achieving a high permeability of 697.3 Barrer and superior CO2/N2 selectivity up to 51.7. Furthermore, the highly crystalline nature and strong amide bonds of the amide-linked COFs greatly enhance membrane stability, as evidenced by an impressive anti-decomposition temperature of 390.2 degrees C and sustained performance over 28 days. The underlying interaction mechanisms of CO2 adsorption and its diffusion mechanism of the COFs, along with their interfacial compatibility with the Pebax2533 matrix, were comprehensively quantified using GCMC, dcTSTs, and MD simulations. This pioneering study demonstrates that amide-linked COF-based MMMs possess remarkable potential for industrial CO2/N2 separation applications, offering an innovative solution that combines high efficiency with long-term operational stability.

Promoting C─C bond cleavage of ethanol to achieve a complete 12-electron pathway (C1 pathway) for ethanol oxidation reaction (EOR) is crucial for the development of highly efficient direct ethanol fuel cells. In this study, a highly porous ultrathin PdSn nanomesh (NM) with high proportion of low-coordinated edge and step sites is developed for alkaline EOR. The PdSn NM/C catalyst exhibited superior specific activity of 21.9 ± 0.9 mA cm-2 Pd with a significantly enhanced Faradaic efficiency of C1 pathway to CO2. In situ attenuated total reflection surface enhanced infrared absorption spectroscopy measurements demonstrated the significant enhancement of C1 selectivity on PdSn NM/C. Theoretical calculations further revealed the pivotal role of low-coordinated edge and step sites in effectively lowering the activation energy barrier for C─C bond cleavage of CH3CO*. This work provides a strategy for the rational design of highly efficient EOR electrocatalysts through low-coordinated site engineering.

Revealing the exact catalytic sites and reaction mechanism is crucial for the development of highly efficient hydrogen oxidation reaction (HOR) catalysts in anion exchange membrane fuel cells. The surface H is generally accepted as the reaction intermediate, and the binding energy of surface H has been proposed as an important reaction descriptor for HOR, yet the active sites and mechanism still remain inconclusive for HOR on complicated metal hydride catalysts involving both surface H and lattice H. Herein, we studied the H absorption characteristics of Pd to clearly distinguish the roles of lattice H (absorbed H, Habs) and underpotentially deposited hydrogen (adsorbed H, Hupd) on PdH x in HOR. The H absorption capacity and absorption/desorption kinetics were found to be size-dependent on Pd nanoparticles (NPs) ranging from 1.5 to 19.1 nm. The exchange current densities (i 0,s) of PdH x and Habs oxidation activities followed the same correlation with the particle sizes. After the Hupd coverage was reduced by decorating methyl violet molecules on the octahedral and cubic PdH x model catalysts, both the HOR activities and Habs oxidation activities were enhanced. Density functional theory calculations confirmed a nearly optimal H adsorption energy at Habs sites after removing the monolayer of Hupd. We propose that Habs sites are most likely the catalytic sites for HOR, and the Habs at the subsurface may be the reaction intermediate, while Hupd acts as the "spectator" on the PdH x system. These findings distinguish different roles of surface and lattice H in PdH x catalysts, providing different insights into the fundamental understanding of the HOR process on metal hydrides.

Hexaazatrinaphthylene (HATN), a polyheterocyclic aromatic ligand, is ideal for constructing discrete functional coordination complexes. However, its conjugated rigidity has resulted in a great challenge in forming extended structures with only one 3D metal-organic framework (MOF) reported 24 years ago. Herein, by regulation of the dihedral angle between two chelating HATN planes, three new porous HATN-based MOFs (SNNU-231-233) with mononuclear metal centers were successfully synthesized. SNNU-231, a unique 2-fold interpenetrated MOF, was first assembled, but the interpenetration leads to the lost pores. By modulating coordination configurations, the pore channels were successfully opened in SNNU-232 and SNNU-233, leading to a new topology in SNNU-232 and breaking the interpenetration in SNNU-233. All HATN-based MOFs exhibit exceptional thermal stability above 500 °C, surpassing most reported MOF materials. At the same time, SNNU-233 can keep its structure in water from pH = 1 to 14. Specifically, SNNU-233 had outstanding CO2 uptake capacity and separation ability of CO2/N2 due to its strong affinity to CO2 molecules in specific pores with abundant hydrogen bonds and π-force adsorption sites. SNNU-233 also showed significant potential for the simulated low calorific value coal gases with five components of H2 (5.1%), CO (9.1%), CH4 (5.0%), N2 (66.3%), and CO2 (14.3%).

To address the urgent need for antibiotic detection, rapid and reliable sensors are imperative. In this study, a novel dual-lanthanide-ion-modified hydrogen-bonded organic frameworks (HOFs) was developed as a fluorescence sensor, named EuTb@ME-IPA, for norfloxacin (NOR) and ciprofloxacin (CIP) detection. The dual lanthanide ions (Eu3 + and Tb3+) were anchored through the coordination with carboxyl and amino groups in the HOFs. The energy transfer from the HOFs to Eu3+ and Tb3+ endowed the material with dual-emission characteristics. Notably, EuTb@ME-IPA overcame the limitation of traditional materials restricted to single-medium detection, enabling the detection in multi-media: i) ratiometric fluorescence detection in ethanol; ii) fluorescence "turn-on" response in aqueous media; iii) ratiometric fluorescence detection via fluorescent films. All the three detections exhibited rapid response in seconds, high sensitivity with the limits of detection (LODs) as low as 0.048 μM (NOR) and 0.037 μM (CIP), and excellent selectivity. Furthermore, the EuTb@ME-IPA based fluorescent film enabled visual detection in real water samples. In addition, the coordination of carboxyl groups in NOR/CIP with Tb3+ induces an "antenna" effect, which was mechanistically certified through DFT calculations and spectral characterization. This study provides new insights for developing portable antibiotic sensors and advancing fluorescence-based strategies for water quality monitoring. ENVIRONMENTAL IMPLICATION: Ciprofloxacin (CIP) and norfloxacin (NOR), classified as quinolone antibiotics, are emerging environmental contaminants of concern in water. Their low biodegradability leads to persistent accumulation in surface water, which disrupts microbial community homeostasis, induces antibiotic resistance gene dissemination, and threatens human health via food chain bioaccumulation, manifesting as hepatorenal toxicity, intestinal microbiota dysbiosis and neurotoxicity. To assess their environmental risks, a simple radiometric fluorescent sensor of EuTb@ME-IPA was developed to achieve highly sensitive and selective detection in multiple media. It provides technical support for monitoring of quinolone contamination in environmental matrices, thereby supporting ecosystem conservation.

Kanamycin (KAN), a typical aminoglycoside antibiotic, has been frequently found in the environment, which causes threats to human health and ecosystems. Ultrasensitive and reliable antibiotic detection strategies are urgently needed. In this study, we propose a dual-functional MXene-based sensing strategy for antibiotic analysis. The sensing platform is fabricated by extended-gate field-effect transistor (EG-FET) with a commercial MOSFET and an extended gate as the sensing electrode. Through electrostatic interaction, Ti3C2Tx MXene nanosheets are assembled on ITO glass gate and double-stranded DNA (dsDNA) is modified on MXene surface. The dsDNA is composed of ssDNA and its complementary strand (cs-DNA). In particular, the ssDNA is the specific recognition element for KAN. KAN can compete with csDNA and disrupt the base pairing of dsDNA, causing the release of csDNA. Relying on the EG-FET sensing structure, a fluorescence detection strategy is also developed based on the quenching process of fluorophore (6-Carboxyfluorescein, 6-FAM) labeled cs-DNA (6-FAM-csDNA) on Ti3C2Tx MXene, in which the fluorescence intensity of 6-FAM is used as the signal for detecting KAN. This dual-functional MXene-based sensor offers both current response and fluorescence response signals in KAN detection. The reported sensor achieves an ultrasensitive detection performance for KAN with a detection limit of 6.44 fM. The sensor's ability to detect KAN in real water samples further demonstrates its practical application potential in complex environment. This work provides a novel dual-functional strategy for sensitive and highly specific detection of antibiotics, addressing some of the key obstacles in antibiotics detection in various applications.

Effectively separating wide types oil-water mixtures from immiscible to emulsions and in-situ recovering viscous crude oil is an urgent issue in alleviating water pollution and recycling oils. We developed a composite sponge of Cu-HHTP/Fe/PDMS@sponge with superhydrophobicity, excellent photothermal conversion ability and stability for multi-type oils separation from water environments. For light oil-water mixtures, the sponge showed super separation efficiency up to 99.95 % and reusability in the long-term; for oil-in-water emulsion, the separation efficiency was as high as 99.49 %; for recovery of viscous crude oil from water, the absorption capacity of the sponge reached 70 g/g and the continuous absorption rate was up to 6.56 g/min. After soaked in harsh chemical solutions and 500-cycle compression, the sponge still exhibited excellent flexibility and recoverability in viscous oil. The excellent performances of the multifunctional sponge were due to the construction of micro/nano-scale hierarchical structures by PDA and Cu-HHTP, protected with PDMS coating to improve both the hydrophobicity and stability. The introduction of Fe3O4 with Cu-HHTP strengthened the photothermal conversion efficiency with the sponge surface temperature rapidly increased from room temperature to 102.4 degrees C under simulated sunlight exposure (1 kW/m2), and resulted in the sponge can be remote-controlled magnetically. This simultaneous, fast and continuous oil-water separation and adsorption processes can be readily and widely applied for oily water purification and oil-spill cleanup.

This paper numerically studies sodium nitrate (phase change material, PCM) infiltrated into honeycomb ceramic's thermal performance. Findings show higher inlet air velocity enhances heat storage power of both pure honeycomb ceramics and composite phase change heat storage ceramics (CPCMs), shortening CPCMs' phase change time and boosting overall rate. In CPCMs, higher sodium nitrate proportion prolongs phase change time, improving heat storage. At 5 m/s inlet velocity, increasing PCM infiltration from 10 % to 40 % and 50 % negligibly affects average power but raises capacity by 67 % and 90 % respectively. Higher air velocity and PCM infiltration accelerate sodium nitrate melting in CPCMs, increasing latent heat share and reducing sensible heat, though the latter remains significant.

A novel surface molecularly imprinted polymers-based dual-mode nanoprobe, NH2-MIL-53(Al)@PDA-MIPs/ AuNPs, was developed for fluorescence (FL) and surface-enhanced Raman scattering (SERS) detection of 4-Nitro- phenol (4-NP) in real water samples. By integrating the advantage of rapid visual detection in FL mode with the advantage of ultrasensitive sensing in SERS mode, the FL-SERS dual-modal approach offers cross-verification of results and extends the detection range. The incorporation of NH2-MIL-53(Al) as carriers not only improved the MIPs stability and prevented the deformation of the imprinting cavity, but also provided stable emission signals, eliminating the need for complex fluorescence sources preparation. The PDA-based MIPs layer isolated NH2-MIL- 53(Al) from the external interferences, providing selective cavities for improved specificity. Additionally, the functional groups on the surface of PDA-based MIPs facilitated the in-situ reduction of AuNPs to create the SERS substrate. The FL-SERS dual-mode nanoprobe exhibited excellent performance, with limits of detection (LOD) of 2.56 nM for FL mode and 1.3 pM for SERS mode. The imprinting factors were calculated to be 13.15 for FL mode and 6.06 for SERS mode, indicating the strong imprinting efficiency. Moreover, real sample applications demonstrated satisfactory recoveries ranging from 96.38 % to 101.78 %, underscoring the practical utility of the sensor in environmental monitoring. The FL-SERS dual-mode nanoprobe thus holds great potential as a versatile tool for future practical application in the sensitive detection of 4-NP in complex water environment.

Mixed matrix composite membranes (MMCMs) have shown advantages in reducing VOCs and CO2 emissions. Suitable composite layer, substrate, and good compatibility between the filler and the matrix in the composite layer are critical issues in designing MMCMs. This work develops a high-performance UiO-66-NA@PDMS/MCE for VOCs adsorption and CO2 permea-selectivity, based on a simple and facile fabrication of composite layer using amidation-reaction approach on the substrate. The composite layer shows a continuous morphological appearance without interface voids. This outstanding compatibility interaction between UiO-66-NH2 and PDMS is confirmed by molecular simulations. The Si─O functional group and UiO-66-NH2 in the layer leads to improved VOCs adsorption via active sites, skeleton interaction, electrostatic interaction, and van der Waals force. The layer and ─CONH─ also facilitate CO2 transport. The MMCMs show strong four VOCs adsorption and high CO2 permeance of 276.5 GPU with a selectivity of 36.2. The existence of VOCs in UiO-66-NA@PDMS/MCE increases the polarity and fine-tunes the pore size of UiO-66-NH2, improving the affinity towards CO2 and thus promoting the permea-selectivity for CO2, which is further verified by GCMC and EMD methods. This work is expected to offer a facile composite layer manufacturing method for MMCMs with high VOC adsorption and CO2 permea-selectivity.

Covalent organic frameworks (COFs) are promising photocatalysts for H2O2 production from water via oxygen reduction reaction (ORR). The design of COFs for efficient H2O2 production indubitably hinges on an in-depth understanding of their ORR mechanisms. In this work, taking an imine-linked COF as an example, we demonstrate that protonation of the functional units such as imine, amine, and triazine, is a highly efficient strategy to upgrade the activity levels for H2O2 synthesis. The protonation not only extends the light absorption of the COF but also provides proton sources that directly participate in H2O2 generation. Notably, the protonation simplifies the reaction pathways of ORR to H2O2, i.e. from an indirect superoxide radical ( ) mediated route to a direct one-step two-electron route. Theoretical calculations confirm that the protonation favors H2O2 synthesis due to easy access of protons near the reaction sites that removes the energy barrier for generating *OOH intermediate. These findings not only extend the mechanistic insight into H2O2 photosynthesis but also provide a rational guideline for the design and upgradation of efficient COFs.