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Carbon nanotubes (CNTs) are nanoscale tubular materials with superior mechanical strength and electronic properties. However, the conventional CNTs are inherently non‐piezoelectric, mainly due to the lack of polar structures with pure carbon elements. The direct synthesis of fully conjugated and polarized organic nanotubes with desired piezoelectric properties remains a challenge. Herein, we report the bottom‐up synthesis of a new type of covalent triazine‐based nanotube (CTN‐1) as a novel piezoelectric material. The CTN‐1 comprises of high surface area, nitrogen‐rich and fully conjugated structure, which provides a series of merits for piezoelectric catalytic processes. These structural features combined with one‐dimensional tubular morphology endow CTN‐1 with excellent mechanical stimuli response and thus displaying prominent piezoelectric properties via pronounced nanocurvature effect. We further show that the CTN‐1 enables the efficient synthesis of H2O2 from water in the air via mechanical energy conversion, with an excellent piezocatalytic H2O2 evolution rate of 4115 μmol g−1 h−1, which exceeds other reported piezoelectric materials. The piezocatalysis by the CTN‐1 can be practically integrated into a self‐Fenton system, which exhibits excellent pollutant degradation capability. This work demonstrates the enormous potential of a new type of piezoelectric synthetic nanotube from organic frameworks for the in situ synthesis valuable chemicals. [ABSTRACT FROM AUTHOR]

The appearance of disordered lithium dendrites and fragile solid electrolyte interfaces (SEI) significantly hinder the serviceability of lithium metal batteries. Herein, guided by theoretical predictions, a multi‐component covalent triazine framework with partially electronegative channels (4C‐TA0.5TF0.5‐CTF) is incorporated as a protective layer to modulate the interface stability of the lithium metal batteries. Notably, the 4C‐TA0.5TF0.5‐CTF with optimized electronic structure at the molecular level by fine‐tuning the local acceptor‐donor functionalities not only enhances the intermolecular interaction thereby providing larger dipole moment and improved crystallinity and mechanical stress, but also facilitates the beneficial effect of lithiophilic sites (C−F bonds, triazine cores, C=N linkages and aromatic rings) to further regulate the migration of Li+ and achieve a uniform lithium deposition behavior as determined by various in‐depth in/ex situ characterizations. Due to the synergistic effect of multi‐component organic functionalities, the 4C‐TA0.5TF0.5‐CTF modified full cells perform significantly better than the common two/three‐component 2C‐TA‐CTF and 3C‐TF‐CTF electrodes, delivering an excellent capacity of 116.3 mAh g−1 (capacity retention ratio: 86.8 %) after 1000 cycles at 5 C and improved rate capability. This work lays a platform for the prospective molecular design of improved organic framework relative artificial SEI for highly stable lithium metal batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] The development of a low-cost, highly active, and non-precious metal catalyst for oxygen evolution reaction (OER) is of great significance. Multi-metallic catalysts containing Fe, Co, and Ni exhibit remarkable OER activity, while the specific contributions of each component and the synergistic effects in the ternary metal catalyst has remained elusive. In this work, we synthesized a series of S and N-doped mono-metallic, bi-metallic, and tri-metallic hollow carbon sphere electrocatalysts (M−SNC) with the goal of enhancing the catalysts OER activity and shedding light on the unique roles and synergistic effects of the various metals in the FeCoNi ternary metal catalyst. Our systematic analyses demonstrated the introduction of Fe effectively reduces the overpotential, Co accelerates the kinetics of OER, and the addition of Ni further improves the OER performance. Benefiting from the synergistic effects, the FeCoNi-SNC exhibits a low overpotential of 270 mV, with no morphological or structural changes after reaction, maintaining high activity for 72 h at 10 mA cm−2. Moreover, the assembled FeCoNi-SNC || Pt/C water electrolysis device operates for 65,000 s with minimal degradation, demonstrating its potential for practical application. This work presents a synergy strategy for the preparation of low-cost and highly efficient OER catalysts and further provides insights into the rational design and preparation of multicomponent catalysts. [ABSTRACT FROM AUTHOR]

Porphyrins‐based porous organic polymers (POP) were widely used in photocatalytic oxidation under visible light owing to their superiority in the activation of oxygen. In contrast, the efficiency is usually limited due to the fast recombination and slow electron transfer. Herein, we report the use of a trioporphyrins‐based covalent triazine framework (Por‐CTF) as visible‐light‐active photocatalyst for the coupling oxidative of amines to imines at room temperature. By incorporating the π‐conjugated porphyrin building block led to the enhanced electron transport between molecules, and the extended recombination time of excited electrons. The photocatalytic efficiency of Por‐CTF is superior to that of polymer in absence of triazine framework (POP‐TSP), which was prepared by radical polymerization using tetra‐(4‐vinylphenyl) porphyrin (TSP) as monomer. Por‐CTF catalyst presented excellent efficiency for various primary amines and stability. This work provides a reasonable guidance of catalyst molecular structure design for enhancing efficiency in the photocatalytic oxidation. [ABSTRACT FROM AUTHOR]

We introduce the first mechanochemical cyclotrimerization of nitriles, a facile strategy for synthesizing triazine‐containing molecules and materials, overcoming challenges related to carbonization and solubility. Conducting this solid‐state approach in a mixer ball mill with 4‐Methylbenzonitrile, we synthesize Tris(4‐methylphenyl)‐1,3,5‐triazine quantitatively in as little as 90 minutes. Just as fast, this mechanochemical method facilitates the synthesis of the covalent triazine framework CTF‐1 using 1,4 Dicyanobenzene. Material characterization confirms its porous (650 m2 g−1) and crystalline nature. Adjusting the induced mechanical energy allows control over the obtained stacking conformation of the resulting CTFs ‐ from a staggered AB arrangement to an eclipsed AA stacking conformation. Finally, a substrate scope demonstrates the versatility of this approach, successfully yielding various CTFs. [ABSTRACT FROM AUTHOR]

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The catalytic oxidation of alcohols is an important transformation in the chemical industry. Carbon materials with a large surface area and N doping show great promise as metal-free catalysts for the reaction. In this study, a rich N-containing covalent triazine framework polymerized by cyanuric chloride and p-phenylenediamine was used to synthesize N-doped porous carbon with the assistance of a pore-forming agent—NaCl. First, the mass ratio of the polymer/NaCl was optimized to 1:9. Then, the influence of the pyrolysis temperatures (700–1000 °C) on the materials was studied in detail. It was found that the carbon materials were gradually exfoliated by molten salt at high temperatures. XRD and Raman characterizations showed them with a certain graphitization. The optimal doped carbon CNN-1-9-900 achieved the highest surface area of 199.03 m2g−1 with the largest pore volume of 0.29 cm3g−1. Furthermore, it had a high N content of 9.9 at% with the highest relative proportion of pyridinic/graphitic N. Due to the synergistic effect between the surface area and pyridinic/graphitic N, CNN-1-9-900 showed the best performance for benzyl alcohol oxidation with TBHP at moderate conditions, and the process also worked for its derivatives. [ABSTRACT FROM AUTHOR]

Investigations into the selective oxidation of inert sp3 C−H bonds using polymer photocatalysts under mild conditions have been limited. Additionally, the structure‐activity relationship of photocatalysts often remains insufficiently explored. Here, a series of thiophene‐based covalent triazine frameworks (CTFs) are used for the efficient and selective oxidation of hydrocarbons to aldehydes or ketones under ambient aerobic conditions. Spectroscopic methods conducted in situ and density functional theory (DFT) calculations revealed that the sulfur atoms within the thiophene units play a pivotal role as oxidation sites due to the generation of photogenerated holes. The effect of photogenerated holes on photocatalytic toluene oxidation was investigated by varying the length of the spacer in a CTF donor‐acceptor based photocatalyst. Furthermore, the manipulation of reactive oxygen species was employed to enhance selectivity by weakening the peroxidative capacity. As an illustrative example, this study successfully demonstrated the synthesis of a precursor of the neurological drug AMG‐579 using a photocatalytic protocol. [ABSTRACT FROM AUTHOR]

Ammonia borane (AB) is a promising candidate as a hydrogen reservoir in terms of both dihydrogen storage and hydrogen source for transfer hydrogenation (TH) to unsaturated organic substrates. Ultrasmall Ni nanoparticles (NPs) have been synthesized by metal vapor synthesis (MVS) and supported on a selected covalent triazine framework (CTFPh). The physical and chemical properties of the Ni/CTFPh nanocomposite have been thoroughly investigated. Despite the high Ni loading (10 wt %), the material exhibits well-dispersed ultrasmall Ni nanoparticles (2.2 nm), unveiling the non-innocent role of the N-doped templating carrier toward NPs dispersion and stabilization. The Ni/CTFPh has shown excellent catalytic performance in the AB hydrolysis and AB transfer hydrogenation (AB-TH) for the conversion of a variety of nitroarenes, including halogen-substituted ones, into the corresponding anilines. As for the latter process, Ni/CTFPh has unveiled a remarkable catalytic efficiency, durability, and reusability under both batch and continuous-flow operative conditions. Noteworthily, whatever the catalytic process at work, Ni/CTFPh certainly ranks or even outperforms most Ni-based systems of the state-of-the-art, including its Ni/VXC analogue (Ni 10 wt % prepared by MVS technique) synthesized using a plain and undoped carbon support (i.e., Vulcan XC-72R). [ABSTRACT FROM AUTHOR]

Membrane separation of aromatics and aliphatics is a crucial requirement in chemical and petroleum industries. However, this task presents a significant challenge due to the lack of membrane materials that can endure harsh solvents, exhibit molecular specificity, and facilitate easy processing. Herein, we present a novel approach to fabricate a covalent triazine framework (CTF) membrane by employing a mix‐monomer strategy. By incorporating a spatial monomer alongside a planar monomer, we were able to subtly modulate both the pore aperture and membrane affinity, enabling preferential permeation of aromatics over aliphatics with molecular weight below 200 Dalton (Da). Consequently, we achieved successful all‐liquid phase separation of aromatic/aliphatic mixtures. Our investigation revealed that the synergistic effects of size sieving and the affinity between the permeating molecules and the membrane played a pivotal role in separating these closely resembling species. Furthermore, the membrane exhibited remarkable robustness under practical operating conditions, including prolonged operation time, various feed compositions, different applied pressure, and multiple feed components. This versatile strategy offers a feasible approach to fabricate membranes with molecule selectivity toward aromatic/aliphatic mixtures, taking a significant step forward in addressing the grand challenge of separating small organic molecules through membrane technology. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Covalent triazine framework nanosheets (CTF NSs), an emerging class of two‐dimensional nanomaterials, have received great attention due to their abundant active sites, permanent porosity, molecular structural diversity, superior chemical/thermal stability, and short charge diffusion path, enabling technological breakthroughs in a myriad of applications. The forefront developments and applications of CTF NSs as photocatalysts and electrochemical electrodes have conferred superior performance and made great impact in the field of energy and advanced catalysis. This forward‐looking review aims to summarize the research trends, synthesis, properties of CTF NSs and their CTF counterpart, and highlight their progress in applications with respect to energy storage and conversion devices. Finally, the current challenges and future perspectives for CTF NSs are also presented. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Covalent triazine framework nanosheets (CTF NSs), an emerging class of two‐dimensional nanomaterials, have received great attention due to their abundant active sites, permanent porosity, molecular structural diversity, superior chemical/thermal stability, and short charge diffusion path, enabling technological breakthroughs in a myriad of applications. The forefront developments and applications of CTF NSs as photocatalysts and electrochemical electrodes have conferred superior performance and made great impact in the field of energy and advanced catalysis. This forward‐looking review aims to summarize the research trends, synthesis, properties of CTF NSs and their CTF counterpart, and highlight their progress in applications with respect to energy storage and conversion devices. Finally, the current challenges and future perspectives for CTF NSs are also presented. [ABSTRACT FROM AUTHOR]

The production of hydrogen via electrocatalytic reduction of water using metal-free nanomaterials as the catalyst is a promising and ultimate green approach. Graphitic carbon nitride, covalent organic frameworks, and covalent triazine frameworks (CTFs) are some of the nanostructured materials that are investigated for this purpose. Currently, these materials still lack the efficiency to compete with other techniques (electrolysis). This is because the reaction mechanism and active sites are, in many cases, still poorly understood. In this work, we report a set of metal-free nanostructure-based electrocatalysts, phosphorus covalent triazine frameworks (PCTFs), for electrocatalytic hydrogen production. The hydrogen evolution reaction (HER) performance of PCTF-based nanomaterials is ascribed to the synergistic effect of isolated single nitrogen and phosphorus sites on the large surface area. By combining both experimental and theoretical studies, we found that especially the pyridinic-nitrogen species are the most active sites for the HER. The presence of phosphorus next to the pyridinic-N enhances the HERs. The present results provide a better understanding of the importance of different heteroatoms in nanomaterials as active sites in HERs. Theoretical studies confirmed that phosphorus, being electron rich, creates high electron densities on the nearby N atoms of the CTF materials and intensifies the HER process. [ABSTRACT FROM AUTHOR]

Electrochemical two‐electron water oxidation (2e WOR) is gaining surging research traction for sustainable hydrogen peroxide production. However, the strong oxidizing environment and thermodynamically competitive side‐reaction (4e WOR) posit as thresholds for the 2e WOR. We herein report a custom‐crafted covalent triazine network possessing strong oxidizing properties as a proof‐of‐concept metal‐free functional organic network electrocatalyst for catalyzing 2e WOR. As the first‐of‐its‐kind, the material shows a maximum of 89.9 % Faradaic Efficiency and 1428 μmol/h/cm2 H2O2 production rate at 3.0 V bias potential (vs reversible hydrogen electrode, RHE), which are either better or comparable to the state‐of‐the‐art electrocatalysts. We have experimentally confirmed a stepwise 2e WOR mechanism which was further computationally endorsed by density functional theory studies. [ABSTRACT FROM AUTHOR]

Electrochemical two‐electron water oxidation (2e WOR) is gaining surging research traction for sustainable hydrogen peroxide production. However, the strong oxidizing environment and thermodynamically competitive side‐reaction (4e WOR) posit as thresholds for the 2e WOR. We herein report a custom‐crafted covalent triazine network possessing strong oxidizing properties as a proof‐of‐concept metal‐free functional organic network electrocatalyst for catalyzing 2e WOR. As the first‐of‐its‐kind, the material shows a maximum of 89.9 % Faradaic Efficiency and 1428 μmol/h/cm2 H2O2 production rate at 3.0 V bias potential (vs reversible hydrogen electrode, RHE), which are either better or comparable to the state‐of‐the‐art electrocatalysts. We have experimentally confirmed a stepwise 2e WOR mechanism which was further computationally endorsed by density functional theory studies. [ABSTRACT FROM AUTHOR]

Electrochemical two‐electron water oxidation (2e WOR) is gaining surging research traction for sustainable hydrogen peroxide production. However, the strong oxidizing environment and thermodynamically competitive side‐reaction (4e WOR) posit as thresholds for the 2e WOR. We herein report a custom‐crafted covalent triazine network possessing strong oxidizing properties as a proof‐of‐concept metal‐free functional organic network electrocatalyst for catalyzing 2e WOR. As the first‐of‐its‐kind, the material shows a maximum of 89.9 % Faradaic Efficiency and 1428 μmol/h/cm2 H2O2 production rate at 3.0 V bias potential (vs reversible hydrogen electrode, RHE), which are either better or comparable to the state‐of‐the‐art electrocatalysts. We have experimentally confirmed a stepwise 2e WOR mechanism which was further computationally endorsed by density functional theory studies. [ABSTRACT FROM AUTHOR]

Electrochemical two‐electron water oxidation (2e WOR) is gaining surging research traction for sustainable hydrogen peroxide production. However, the strong oxidizing environment and thermodynamically competitive side‐reaction (4e WOR) posit as thresholds for the 2e WOR. We herein report a custom‐crafted covalent triazine network possessing strong oxidizing properties as a proof‐of‐concept metal‐free functional organic network electrocatalyst for catalyzing 2e WOR. As the first‐of‐its‐kind, the material shows a maximum of 89.9 % Faradaic Efficiency and 1428 μmol/h/cm2 H2O2 production rate at 3.0 V bias potential (vs reversible hydrogen electrode, RHE), which are either better or comparable to the state‐of‐the‐art electrocatalysts. We have experimentally confirmed a stepwise 2e WOR mechanism which was further computationally endorsed by density functional theory studies. [ABSTRACT FROM AUTHOR]

A chemical strategy of triazole group functionalization to modify two-dimensional covalent triazine framework nanosheets is developed, which effectively counteract the unwanted quantum size effect and ineffective electron screening in polymeric semiconductors with reduced dimensionality, as well as provide highly active sites for O 2 adsorption. This results in a widen light absorption range and enhance charge separation in the low-dimensional polymer, establishing a H 2 O 2 production rate of 4068 μmol h−1 g−1 with apparent quantum efficiency of 4.5 % at 400 nm. [Display omitted] Two-dimensional (2D) polymeric semiconductors, especially covalent triazine framework (CTF) nanosheets with aromatic triazine linkages are emerging as attractive metal-free photocatalysts owing to their predictable structures, good semiconducting properties, and high stability. However, the quantum size effect and ineffective electron screening of 2D CTF nanosheets cause an enlargement of electronic band gap and high excited electron-hole binding energies, which lead to low-level enhancements in photocatalytic performance. Herein, we present a novel triazole groups functionalized CTF nanosheet (CTF-LTZ) synthesized by facile combination of ionothermal polymerization and freeze-drying strategy from the unique letrozole precursor. The incorporation of the high-nitrogen-containing triazole group effectively modulates the optical and electronic properties, resulting in narrowed bandgap from 2.92 eV for unfunctionalized CTF to 2.22 eV for CTF-LTZ and dramatically improved charge separation, as well as highly-active sites for O 2 adsorption. As a result, CTF-LTZ photocatalyst exhibits excellent performance and superior stability in H 2 O 2 photosynthesis, with a high H 2 O 2 production rate of 4068 μmol h−1 g−1 and a remarkable apparent quantum efficiency of 4.5 % at 400 nm. This work provides a simple and effective approach for rational design highly-efficient polymeric photocatalysts for H 2 O 2 production. [ABSTRACT FROM AUTHOR]

The catalytic oxidation of alcohols is an important transformation in the chemical industry. Carbon materials with a large surface area and N doping show great promise as metal-free catalysts for the reaction. In this study, a rich N-containing covalent triazine framework polymerized by cyanuric chloride and p-phenylenediamine was used to synthesize N-doped porous carbon with the assistance of a pore-forming agent—NaCl. First, the mass ratio of the polymer/NaCl was optimized to 1:9. Then, the influence of the pyrolysis temperatures (700–1000 °C) on the materials was studied in detail. It was found that the carbon materials were gradually exfoliated by molten salt at high temperatures. XRD and Raman characterizations showed them with a certain graphitization. The optimal doped carbon CNN-1-9-900 achieved the highest surface area of 199.03 m2g−1 with the largest pore volume of 0.29 cm3g−1. Furthermore, it had a high N content of 9.9 at% with the highest relative proportion of pyridinic/graphitic N. Due to the synergistic effect between the surface area and pyridinic/graphitic N, CNN-1-9-900 showed the best performance for benzyl alcohol oxidation with TBHP at moderate conditions, and the process also worked for its derivatives.

The ability to molecularly engineer materials is a powerful tool toward increasingly performing heterogeneous catalysts. Porous organic polymers stand out as photocatalysts due to their high chemical stability, outstanding optoelectronic properties and their easy and tunable syntheses. In photocatalysis, the insertion of photosensitizing π‐extended molecules into molecularly well‐defined donor‐acceptor junctions is supposed to increase the catalytic activity, but yet remain experimentally underdeveloped. This study presents a pyrene‐based Covalent Triazine Framework (CTF) synthesized through a polycondensation approach, which was designed to contain a molecularly‐defined pyrene‐triazine‐bipyridine donor‐acceptor‐acceptor triad as the repetition unit of the CTF. The CTF is an efficient photocatalyst for hydrogen evolution from water reaching a significant production rate of 61.5 mmolH2/h/gcat. Moreover, the same CTF can easily be used as porous macroligand for an organometallic Rh complex to efficiently catalyze the carbon dioxide photoreduction into formic acid under visible light. [ABSTRACT FROM AUTHOR]

The development of efficient heterostructures combining covalent organic frameworks (COFs) and ideal semiconductors can significantly improve photocatalytic performance for pollutant degradation. Herein, we present the design, synthesis, and characterization of a core‐shell‐structured nanocomposite comprising covalent triazine framework‐encased Fe3O4 magnetic particles employed as a heterojunction photocatalyst for activating peroxymonosulfate (PMS) in phenol degradation. The distinctive internal structure between the TpMa shell (Tp=2,4,6‐trihydroxy‐1,3,5‐benzenetricarboxaldehyde, Ma=melamine) and the Fe3O4 core (Fe3O4@TpMa) facilitated charge transfer and accelerated charge separation. Furthermore, PMS served as an electron acceptor, enhancing photogenerated charge separation and maximizing the production of reactive oxygen species. The Fe3O4@TpMa/PMS system demonstrated remarkable photocatalytic performance and stability, achieving complete phenol degradation (10 mg L−1) in 40 min. The exceptional photocatalytic activity resulted from the synergistic effect of ⋅OH, SO4⋅−, O2⋅−, 1O2, and h+ generated in the Fe3O4@TpMa/PMS system during the degradation process. Overall, this material offers excellent potential for solar‐driven pollutant degradation and enables the development of COF‐based materials for wastewater treatment applications. [ABSTRACT FROM AUTHOR]

Using photocatalytic oxidation to convert basic chemicals into high value compounds in environmentally benign reaction media is a current focus in catalytic research. The challenge lies in gaining controllability over product formation selectivity. We design covalent triazine frameworks as heterogeneous, metal‐free, and recyclable photocatalysts for visible‐light‐driven switchable selective oxidation of styrene in pure water. Selectivity in product formation was achieved by activation or deactivation of the specific photogenerated oxygen species. Using the same photocatalyst, by deactivation of photogenerated H2O2, benzaldehyde was obtained with over 99 % conversion and over 99 % selectivity as a single product. The highly challenging and sensitive epoxidation of styrene was carried out by creating peroxymonocarbonate as an initial epoxidation agent in the presence of bicarbonate, which led to formation of styrene oxide with a selectivity up to 76 % with near quantitative conversion. This study demonstrates a preliminary yet interesting example for simple control over switchable product formation selectivity for challenging oxidation reactions of organic compounds in pure water. [ABSTRACT FROM AUTHOR]

The tunability of porous covalent triazine frameworks (CTFs) can mitigate poor photostability and rapid hole-electron recombination. Herein, an excellent improvement of visible light–driven photocatalytic pollutant degradation was achieved using a hybrid semiconductor of covalent triazine framework-zinc ferrite spinel catalysts (CTF-ZnFe2O4). The as-prepared CTF-ZnFe2O4 composites were fabricated using a facile one-pot ionothermal method. The hybrid photocatalysts were identified using X-ray diffraction (XRD), scanning electron microscopy/energy-dispersive X-ray (SEM–EDX), X-ray photoelectron spectrometer (XPS), Brunauer–Emmett–Teller (BET), Fourier transform infrared (FTIR), and UV–visible diffuse reflection spectroscopy (UV–vis DRS) characterizations. The analysis reveals that hybridization successfully ensued and altered the crystallinity structure, morphology, surface area, and bandgap energy of hybrid material. It was found that CTF-ZnFe2O4 90:10 is very effective for the degradation of MB in a UV–vis light photocatalytic process with the efficiency of 95.4% and kobs of 0.421 min−1 for degradation of 50 mg/L MB with 0.5 g/L dosages for 120 min. Additionally, the scavenger study, effect of additional oxidants, and stability were performed for the practical application of a hybrid photocatalyst. CTF-ZnFe2O4 90:10 shows outstanding pollutant degradation in sunlight irradiation and high stability with only a 5.2% reduction after a five-times sequential recycling process. Moreover, the photocatalytic mechanism of as-prepared CTF-ZnFe2O4 was mainly influenced by O 2 ∙ - radical compared to h + vb and ∙ OH radicals. Overall, The as-prepared CTF-ZnFe2O4 shows significant potential to be utilized for photocatalytic wastewater treatment. [ABSTRACT FROM AUTHOR]

Herein, a series of covalent triazine framework/bismuth vanadate (CTF/BiVO4) heterojunction catalysts were prepared using the hydrothermal method. The mechanism of the CTF/BiVO4 heterojunction photocatalyst in the system was examined to provide a theoretical basis for constructing a high-efficiency photocatalysis composite system for removing organic pollutants from water. Compared with CTF and BiVO4 catalysts alone, composite materials have been shown to have significantly higher degradation efficiencies against organic pollutants in water. Moreover, the degradation effect was found to be optimal when the mass ratio of CTF to BiVO4 was 1:1 (1-CTF/BiVO4). On the basis of physicochemical characterization results, it was concluded that the effective construction of CTF/BiVO4 composite photocatalyst material systems and the formation of type II heterojunction structures between CTF and BiVO4 effectively promote the separation of photogenerated carriers and increase the interface charge transfer efficiency. [ABSTRACT FROM AUTHOR]

Fluoroquinolones (FQL) are ubiquitous in aquatic environments due to their widespread use, posing a serious environmental threat. In this regard, a novel Bi 12 O 15 Cl 6 /CTF-1 (BTF) photocatalyst was prepared by integrating a covalent triazine framework (CTF-1) with Bi 12 O 15 Cl 6 by a simple wet-impregnation method for removing levofloxacin (LFX), an FQL-based antibiotic, from an aqueous solution. Under optimal conditions, BTF (III) (comprising 20 % CTF-1) showed the highest photocatalytic activity, achieving approximately 94 % LFX (10 mg/L) degradation in 120 min under visible light with a pseudo-kinetic rate constant of 0.02072 min−1. This can be attributed to the reduced recombination rate and efficient transfer and separation of photoinduced charge carriers. The photocatalyst demonstrated remarkable stability and reusability. The radical trapping experiment revealed O 2 • − and h+ to be the primary active species facilitating the photocatalytic degradation of LFX. Furthermore, the seed germination test affirmed treated effluent to be non-phytotoxic and suitable for irrigation. [Display omitted] • Bi 12 O 15 Cl 6 /CTF-1 (BTF) photocatalyst was synthesized via the facile wet impregnation method. • CTF-1 incorporation improved the charge transfer and separation efficiency of the photocatalyst. • Approximately 94 % levofloxacin degradation was achieved in 120 min under visible light. • Germination index value of 86 % indicated the absence of phytotoxicity in the treated effluent. [ABSTRACT FROM AUTHOR]

• Self-supporting porous COF-MMMs were fabricated through room temperature polymerization. • The incorporation of PAN enhanced the mechanical properties and hydrophilicity of the CTF-MMMs. • The introduction of pore-forming agents substantially increased the porosity and water permeance of the CTF-MMMs. • The CTF-MMM demonstrated outstanding performance in dye/salt separation and maintained structural stability under harsh conditions. Mixed matrix membranes (MMMs) incorporating porous covalent organic frameworks (COFs) as fillers have garnered significant attention in membrane separation for water purification. Covalent triazine frameworks (CTFs) possess high thermochemical stability, an inherent triazine conjugate structure, and tunable pore size. Despite these attributes, CTFs have been underutilized in MMMs. In this study, CTF-based porous MMMs were fabricated by blending 4,4′-biphenyldicarbonitrile (BPCN) monomer with polyacrylonitrile (PAN) and employing titanium dioxide nanoparticles (TiO 2 NPs) as a pore-forming agent. The nature of PAN also makes the mixed matrix membranes have better hydrophilicity and mechanical properties. The optimized CTF-MMM exhibited an impressive water permeance of ∼ 204 L m−2 h−1 bar−1, accompanied by a remarkable dye rejection of ∼ 99 % and a low salt rejection. Moreover, the CTF-MMM demonstrated sustained water permeance and separation performance even after 48 h. This work introduces a synthesis strategy for fabricating high-performance CTF-based porous mixed matrix membranes, showcasing significant potential for applications in dye/salt separation. [ABSTRACT FROM AUTHOR]

Due to the polorization effect of D-π-A TAPT and fast charge delivery in AA-CTF of AA-CTF/TAPT, the Z-Scheme heterojunction provides an efficacious carrier migration for improving photocatalytic CO 2 RR. [Display omitted] • D-π-A TAPT and non-D-A TAPB molecules are integrated with CTF, respectively. • The interfacial polarization in AA-CTF/TAPT highly devote to charge separation. • the fast charge transfer channel in AA-CTF is conductive to carrier transport. • The optimal CO 2 RR conducted by AA-CTF/TAPT gives nearly 100% reaction selectivity. Herein, two conjugated molecules, i.e., D-π-A TAPT and non-D-A TAPB, are finely designed to incorporate with covalent triazine framework (CTF) in A-A and A-B stacking mode via π-π interaction, respectively. The transient photocurrent response of the generated AA-CTF/TAPT Z-Scheme heterostructure is 1.14 × 10-7 A, significantly higher than that of the other two metal-free heterostructures (AA-CTF/TAPB and AB-CTF/TAPT). The promoted photocarrier transportation is attributed to strong polarization (dipole moment = 2.634 D) imposed by the D-π-A effect in TAPT that motivates the interfacial charge separation, and the coexisting charge transfer channel built by the ordered A-A stacking mode in AA-CTF that expedites the charge delivery. The photocatalytic CO 2 conversion conducted by AA-CTF/TAPT gives the optimal CO conversion rate as 7.47 μmol·g−1·h−1, and with nearly 100 % product selectivity obtained, which is attributable to the lower energy barrier of CO desorption barrier (−1.07 eV) rather than that of CHO* formation (1.52 eV) for generating CH 4. [ABSTRACT FROM AUTHOR]

[Display omitted] • Unmodified cellulose II porous beads loaded with covalent triazine framework. • The thickness of CTF grown within the CBCs could be controlled at 32–83 nm. • CBCs shows a high RhB removal capacity and fast MB adsorption rate. • Molecular dynamics simulation of CTF growth on cellulose crystal surfaces mechanism. cellulose II beads@covalent triazine frameworks (CBCs) are prepared by in situ growth of ultra-dispersed covalent triazine frameworks (CTF) using unmodified regenerated cellulose beads (CBs) as templates. The CBCs as a whole are three-dimensional structures consisting of a layered pore structure and a continuous ultrathin CTF, which combines a functional surface with highly efficient mass transfer. The thickness of the CTF in the prepared CBCs can be controlled at 32–83 nm, which enables the CBC to have a dye adsorption efficiency of up to 191 mg g−1 and an ultrafast dye removal time (Methylene Blue, 0.5 min, 95 %). Molecular dynamics simulations revealed the mechanism for CTF growth on the surface of unmodified cellulose II rather than on the surface of cellulose Ⅰ, and the effects of the hydrophilic/hydrophobic surfaces of cellulose I and cellulose II on the growth of CTF were determined. This is the first use of unmodified cellulose II as a template for the in situ growth of ultrathin CTF and provides important insights into dynamic CTF-cellulose interactions. This research provides a new cost-effective strategy for preparation of ultra-dispersed CTF based on large-scale cellulose templates. [ABSTRACT FROM AUTHOR]

We have synthesized a new hybrid material, Ag0@CTFN in which small-sized Ag-nanoparticles (Ag-NPs) are anchored on the surface of covalent triazine framework nanosheet (CTFN). Here, CTFN works as the support as well as the capping agent for the small-sized Ag-NPs. Ag0@CTFN has been synthesized in a one pot method where Ag-NPs attach with the nitrogen atoms present in the triazin units. This as synthesized Ag0@CTFN material has been characterized by FTIR, XRD, N 2 adsorption desorption analysis, SEM, TEM and XPS analysis. All these characterizations reveal that around 4.97 nm sized Ag-NPs are anchored on the surfaces of layer-like CTFN nanosheets. Ag0@CTFN samples have shown their excellent catalytic activity for the selectively oxazolidinone formation from propargyl alcohol and amine by fixing CO 2 under mild reaction condition. Moreover, this is the first report on Ag0@CTFN hybrid material which catalyze the oxazolidinone synthesis by fixing CO 2. Again, this catalyst has shown their recyclability for oxazolidinone synthesis reaction up to sixth cycle by keeping their activity almost intact. There is no metal or catalyst leaching noticed up to sixth cycle for this reaction. AgNPs decorated Porous polymeric framework was constructed and employed as an efficient reusable heterogeneous catalyst for the synthesis of oxazolidinone from propargyl alcohol and amines by fixing CO 2 under very mild reaction conditions. [Display omitted] • We have synthesized Ag0@CTFN, in which small-sized Ag-nanoparticles are anchored on the surface of covalent triazine framework nanosheet (CTFN). Here, CTFN works as the support as well as the capping agent for the small-sized Ag-NPs. • Moreover, this is the first report in which small-sized Ag-nanoparticles (Ag-NPs) are anchored on the surface of covalent triazine framework nanosheet (CTFN). • The hybrid material, Ag0@CTFN was characterized by FTIR, PXRD, SEM, TEM, N 2 -adsorption desorption, XPS analysis. • The Ag0@CTFN samples showed excellent catalytic activity for the selectively oxazolidinone formation from propargyl alcohol and amine by fixing CO 2 under mild reaction condition. • This Ag0@CTFN acts as a heterogeneous catalyst that can be easily separated from the reaction mixture for reuse. [ABSTRACT FROM AUTHOR]

3D assembled carbon materials, featuring unique hierarchical porosity and interconnected channels, are essential for the advancement of emerging zinc-air batteries (ZABs). In this study, nitrogen (N) and sulfur (S) co-doped 3D carbon nanoholes (N/S-CNHs) are synthesized through a straightforward procedure involving self-assembly followed by carbonization. This process utilizes a hybrid of self-assembled covalent triazine framework and sodium lignosulphonate (CTF@LS) as a multifunctional precursor. The resulting N/S-CNHs exhibit a distinctive nanoholes microstructure composed of interwoven carbon nanoclusters, which facilitates efficient ion and electron transport during the electrocatalytic process. The incorporation of N and S atoms intriguingly alters the wetting properties of the catalyst microenvironment, thereby significantly facilitating the transfer of key intermediates and their interaction with the electrolyte. Consequently, the optimized N/S-CNH-900 demonstrates remarkable electrocatalytic activity for the ORR (E 1/2 = 0.86 V vs RHE), surpassing the performance of state-of-the-art Pt/C electrocatalyst. Theoretical calculations reveal that the synergistic effect of N and S heteroatom doping significantly enhances *OOH desorption and its transformation to O*, thereby markedly accelerating the ORR process. Furthermore, both liquid and quasi-solid ZABs equipped with the N/S-CNH-900 cathode exhibit improved peak power density and specific capacity relative to those employing commercial Pt/C catalysts., (© 2024 Wiley‐VCH GmbH.)

Aqueous Zinc-iodine batteries (ZIBs) are widely viewed as promising energy storage devices due to their high energy density and intrinsic safety. However, they encounter great challenges such as grievous polyiodides shuttle and sluggish iodine (I 2 ) redox reaction kinetics, thus undesirable cycling performance. Here a high-performance ZIB with an ultra-long lifespan is reported through the rational I 2 cathode catalyst design. Specifically, a covalent triazine framework with defect-rich sites and micro-mesoporous structure (i.e., CTF500) is developed as an effective I 2 cathode catalyst. Benefiting from the synergistic effect of micro-mesoporous structure and defect-rich sites for the confinement and conversion of I 2 species, the resulting ZIBs with I 2 loaded CTF500 (I 2 @CTF500) cathode show an ultra-long lifespan over 75,000 cycles at 5 A g -1 , and an impressive cyclic performance over 15,000 cycles at high I 2 loading of 3.59 mg cm -2 , highlighting its commercial application prospect. In/ex situ spectral characterizations combined with theoretical calculations clearly reveal the reversible reaction mechanism of I 2 species in I 2 @CTF500 cathode and the essential role of defect-rich sites in boosting the performance of ZIBs. This work not only guides the design of advanced I 2 cathodes for metal-iodine batteries but also expands the range of possible applications for defect-rich CTFs., (© 2024 Wiley‐VCH GmbH.)

As a high-performance energy storage device consisting of a battery-type anode and a capacitor-type cathode, hybrid lithium-ion capacitors (HLICs) combine the advantages of high energy density of batteries and high power density of capacitors. However, the imbalance in electrochemical kinetics between the battery-type anode and the capacitor-type cathode hinders the further development of HLICs. Fully conjugated covalent organic frameworks have great potential as electrode materials for HLICs due to the designability of their structure. Herein, a fully conjugated covalent triazine framework (PT-CTF) integrating the hexaazatrinaphthylene unit was constructed, which provides abundant active sites (C═N and C═C groups) as the pseudocapacitive anode material for HLICs. And the connection of the triazine unit of PT-CTF improves the molecular conjugate degree, facilitating the transport of electrons. The fabricated PT-CTF||AC HLICs exhibit a high energy density (164.9 Wh kg -1 at 100 mA g -1 ), large power density (13.1 kW kg -1 at 4 A g -1 ), and excellent cycling capability (72% after 10 000 cycles at 2 A g -1 ).

To achieve a superior removal efficiency of iodine from different phases relevant to radioactive iodine emission (129I/131I) for safe nuclear energy, optimized porous architectures with high surface area and large pore volume featuring appropriate pore size/shape and distribution along with a suitable chemical environment are sought. Herein, we report a soft self-templating synthesis strategy utilizing a low-cost and easily accessible 2,5-dimethoxy terephthalonitrile (LOMe) monomer to prepare a nitrogen/oxygen codoped nanoporous covalent triazine framework (MeO-CTF600) possessing an extremely high specific surface area of 2731 m2 g–1 and a record pore volume of 3.33 cm3 g–1. Interestingly, this framework shows extensive bimodal nanoporosity ranging from the micropore (1–2 nm) to narrow mesopore (2–10 nm) region, necessary to achieve superior iodine adsorption. MeO-CTF600 exhibits outstanding iodine capture performance from iodine vapor (578 wt %), including aqueous (221 wt %) and organic (849 mg g–1) solutions of iodine, under nuclear-fuel reprocessing conditions (348 K) compared to benchmark materials. In addition, the framework shows extremely fast adsorption kinetics and regenerability, making it a promising adsorbent tackling all sorts of radioiodine contamination toward clean and safe nuclear power sources. [ABSTRACT FROM AUTHOR]

• Covalent triazine framework encapsulated ultrafine Pd nanoclusters (Pd-NCs@CTF) were successfully synthesized via a novel metal-nitrogen coordination reduction strategy. • Pd-NCs@CTF composite shows a record high turnover frequency toward the ammonia-borane (AB) hydrolysis among monometallic Pd catalysts. • CTF can help maximize the utilization of Pd, stabilize Pd NCs and also modify the surface electronic structure of Pd via a ligand effect. • Positively charged Pd NCs favors the water dissociation, accelerating the kinetics of the AB hydrolysis. • Pd-NCs@CTF is an efficient tandem catalyst toward the hydrogenation of various nitrobenzenes using in situ generated H 2 from the AB hydrolysis. Ammonia borane (AB) represents a promising hydrogen storage material, while high-performing catalysts allowing efficient release of hydrogen from the hydrolysis of AB are desired. Here, Pd nanoclusters (NCs) are successfully immobilized within pores of a bipyridyl covalent triazine framework (CTF-BPDA-TPDH) via a metal-nitrogen coordination reduction strategy. The porous structure and tailored N sites of CTF facilitate the anchoring of Pd ions and the in situ formation of monodisperse Pd NCs confined in the pores of CTF. The resulting Pd-NCs@CTF composites exhibit high activity toward the hydrolysis of AB with turnover frequencies (TOFs) of 273 and 434 mol H2 ·mol−1 Pd ·min−1 in neutral and alkaline solutions, respectively. The Pd-NCs@CTF catalyst is also demonstrated for the tandem dehydrogenation of AB and hydrogenation of nitroarenes featuring short reaction time and high yields. These findings emphasize the promise of the porous CTFs encapsulated metal NCs for active catalysts. [ABSTRACT FROM AUTHOR]

Uranium extraction is the cornerstone of the sustainable development of the nuclear industry. Although a variety of porous framework materials for uranium extraction have been explored over the past few decades, almost all of them have been limited to bulk powder materials. In particular, due to the strong interlayer π-π interaction, the specific recognition sites and photocatalytic active centers of bulk two-dimensional framework materials are severely buried, resulting in the inability to exploit the optimal performance of the materials. In this study, a novel hydroquinone modified covalent triazine frame nanosheets (H-CTF-NSs) is reported for the first time, which is designed for specific extraction and photocatalytic reduction of uranium. The densely distributed hydroquinone and triazine units in the H-CTF-NSs synergistically form high-affinity binding sites, and the ultrathin nanosheets facilitate the exposure of binding sites and catalytically active centers, and accelerate the diffusion of uranyl ions, it is ideally suited as an advanced platform for the selective extraction and efficient reduction of U(VI). Remarkably, H-CTF-NSs demonstrated an unprecedented uranium extraction capacity of 3230.3 mg/g, which is almost 1.71 times that of its bulk counterpart H-CTF, making it one of the best uranium-trapping photocatalysts known to date. [ABSTRACT FROM AUTHOR]

[Display omitted] • Naphthalene-based COFs are used to support Pd nanoparticles. • COF-supported Pd nanoparticles have a small size of 1.2 ± 0.3 nm. • COF-supported Pd nanoparticles show good catalytic performance in formic acid dehydrogenation for generating hydrogen. • COF-supported Pd nanoparticles exhibit good stability. Formic acid (FA) is considered as a kind of promising hydrogen storage materials due to its economic feasibility, safety, stability and high hydrogen density. Nevertheless, it is a challenge to design a high-performance catalyst with high activity, selectivity and stability for the dehydrogenation of FA to generate hydrogen (H 2). Herein, a range of covalent triazine frameworks (CTFs including 1,8-CTF, 1,5-CTF and 2,3-CTF) with abundant nitrogen atoms are developed to support palladium nanoparticles for efficiently catalyzing FA dehydrogenation. Ultrasmall palladium nanoparticles with a size of 1.2 ± 0.3 nm showed near 100 % H 2 selectivity and high catalytic activity in FA dehydrogenation supported by 1,8-CTF. The activation energy of FA dehydrogenation catalyzed by Pd/1,8-CTF reaches 26.17 kJ·mol−1. In addition, Pd/1,8-CTF exhibits high stability and easy recyclability, and the catalytic activity is maintained even after 6 cycles. This work gives a feasible strategy to develop high-efficiency and selective nanocatalysts for H 2 production from FA dehydrogenation. [ABSTRACT FROM AUTHOR]

Iridium oxide (IrOx-NP) and palladium nanoparticles (Pd-NP) were supported on a 2,6-dicyanopyridine-based covalent-triazine framework (DCP-CTF) by energy-saving and sustainable microwave-assisted thermal decomposition reactions in propylene carbonate and in the ionic liquid [BMIm][NTf2]. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) confirm well-distributed NPs with sizes from 2 to 13 nm stabilized on the CTF particles. Metal contents between 10 and 41 wt% were determined by flame atomic absorption spectroscopy (AAS). Nitrogen sorption measurements of the metal-loaded CTFs revealed Brunauer–Emmett–Teller (BET) surface areas between 904 and 1353 m2 g−1. The composites show superior performance toward the hydrogen evolution reaction (HER) with low overpotentials from 47 to 325 mV and toward the oxygen reduction reaction (ORR) with high half-wave potentials between 810 and 872 mV. IrOx samples in particular show high performances toward HER while the Pd samples show better performance toward ORR. In both reactions, electrocatalysts can compete with the high performance of Pt/C. Exemplary cyclic voltammetry durability tests with 1000 cycles and subsequent TEM analyses show good long-term stability of the materials. The results demonstrate the promising synergistic effects of NP-decorated CTF materials, resulting in a high electrocatalytic activity and stability.

[Display omitted] • The first example of covalent triazine frameworks derived from biomass was designed and synthesized. • Heterogeneous catalyst Cp*Ir@CTF-biomass and its homogeneous analog have approximate catalytic activity. • Catalytic activity of Cp*Ir@CTF-biomass is well maintained during six runs. The first example of covalent triazine frameworks derived from biomass was designed and synthesized. Furthermore, an iridium complex Cp*Ir@CTF-biomass was prepared by the coordinative immobilization of [Cp*IrCl 2 ] 2 on the synthesized covalent triazine framework. In the presence of Cp*Ir@CTF-biomass (0.03 mol % Ir), the reaction was carried out for 24 min at 80 °C and an almost complete dehydrogenation of formic acid with an initial TOF of 7627 h−1 was observed. Further experiments confirmed that heterogeneous catalyst Cp*Ir@CTF-biomass and its homogeneous analog [Cp*Ir(pyridine)Cl 2 ] have approximate catalytic activity. Moreover, catalytic activity of Cp*Ir@CTF-biomass is well maintained during six runs. ©2024 Elsevier Inc. All rights reserved. [ABSTRACT FROM AUTHOR]

[Display omitted] • Performance of thiophene-functionalized C 3 N 3 nanosheet as an anode material for LIBs is studied by DFT calculations. • Thiophene enhances the electronic conductivity and Li-ion storage capacity of the pristine C 3 N 3 nanosheet. • Thiophene-functionalized C 3 N 3 nanosheet has a small diffusion barrier (0.35 eV) and a low positive open-circuit voltage (0.09 V) for LIBs. Covalent triazine frameworks (CTFs) are a fascinating type of porous organic materials that exhibit numerous distinct features, such as significant specific surface area, outstanding chemical/thermal stability, and structural modifiability at the molecular level. These features make CTFs highly appealing for utilization in Li-ion batteries (LIBs). However, their low electronic conductivity limits their practical applications. In the present study, the potential anode application of thiophene-functionalized C 3 N 3 nanosheet for LIBs was conducted by dispersion-corrected density functional theory (DFT-D3) calculations. It was found that functionalization of the C 3 N 3 nanosheet with six thiophene groups ((THP) 6 @C 3 N 3) led to the highest reduction (0.19 eV) in the energy gap of the pristine C 3 N 3 nanosheet. A single Li-ion preferably adsorbs between two nitrogen atoms of the triazine ring with an adsorption energy of about 4.59 eV. The absorption of Li-ion resulted in a reduction of the band gap from 1.37 eV to 0.43 eV, indicating enhanced electrical conductivity and superior cycle stability. The fully loaded functionalized nanosheet with nineteen Li-ions at various adsorption sites exhibited a remarkable theoretical specific capacity of 526.55 mAh/g. This configuration also displayed a low open-circuit voltage (0.09 V) and diffusion energy barrier (0.35 eV), ideal as an anode with a rapid charging/discharging rate. Therefore, thiophene-functionalized C 3 N 3 nanosheet demonstrates superior anode performance for LIBs due to its high theoretical specific capacity, small diffusion barrier, and low working voltage. This work can provide insights for the refere development of CTF-based anode materials. [ABSTRACT FROM AUTHOR]

Scalable and eco‐friendly synthesis of crystalline porous covalent triazine frameworks (CTFs) is essential to realize their broad industrial applications but remains a great challenge, which requires the fundamental understanding of the two‐dimensional polymerization mechanism. Herein, we report a universal polyphosphoric acid (H6P4O13)‐catalyzed nitrile trimerization route to synthesize a series of highly crystalline CTFs with high specific surface areas. This new strategy enables the cost‐effective large‐scale fabrication of crystalline CTFs at kilogram level for the first time. Through density functional theory calculation and detailed controlled experiments, we reveal that the polyphosphate acid show much higher catalytic activity for trimerization reaction than its analogues such as P2O5 and H3PO4. Furthermore, the crystalline CTFs with regular porosity and abundant triazine groups exhibit ultrahigh removal efficiency of micropollutants, indicating its great potential in environment remediation. [ABSTRACT FROM AUTHOR]

Scalable and eco‐friendly synthesis of crystalline porous covalent triazine frameworks (CTFs) is essential to realize their broad industrial applications but remains a great challenge, which requires the fundamental understanding of the two‐dimensional polymerization mechanism. Herein, we report a universal polyphosphoric acid (H6P4O13)‐catalyzed nitrile trimerization route to synthesize a series of highly crystalline CTFs with high specific surface areas. This new strategy enables the cost‐effective large‐scale fabrication of crystalline CTFs at kilogram level for the first time. Through density functional theory calculation and detailed controlled experiments, we reveal that the polyphosphate acid show much higher catalytic activity for trimerization reaction than its analogues such as P2O5 and H3PO4. Furthermore, the crystalline CTFs with regular porosity and abundant triazine groups exhibit ultrahigh removal efficiency of micropollutants, indicating its great potential in environment remediation. [ABSTRACT FROM AUTHOR]

Blue light-mediated oxidation of sulfides to sulfoxides with O 2 over TzTz-TA advances in a selective and prompt manner. [Display omitted] Recently, triazine-based two dimensional (2D) porous materials have received increasing attention in photocatalysis. Herein, CTF-1, a covalent triazine framework, was adopted as the blueprint for designing a 2D bespoke photocatalyst. The thiazolo[5,4- d ]thiazole (TzTz) linkage was inserted into the framework of CTF-1, affording TzTz-TA, which belongs to conjugated microporous polymers (CMPs). Rather than the direct insertion via the challenging C H activation, TzTz-TA was assembled from 2,4,6-tris(4-formylphenyl)-1,3,5-triazine and dithiooxamide, in which TzTz was formed in situ by a process of catalyst-free solvothermal condensation. Both CTF-1 and TzTz-TA had similar energy gaps (E g), photocurrents, and charge carrier lifetimes, in line with the similar molecular underpinnings. However, the reduction potential of TzTz-TA is less negative than that of CTF-1 due to the insertion of TzTz linkage, in a more appropriate position for activating O 2 to superoxide (O 2 •–). In return, blue light-mediated oxidation of sulfides to sulfoxides with O 2 over TzTz-TA was accomplished with significantly superior conversions to those over CTF-1. Intriguingly, extensive sulfides could be oxidized to corresponding sulfoxides with outstanding recycling stability of TzTz-TA. Notably, attendance of an induction period was observed during TzTz-TA photocatalysis. This work highlights the vast potential of designing triazine-based porous materials to meet the tailor-made demands, such as the oxidative transformation of organic molecules with O 2. [ABSTRACT FROM AUTHOR]

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Stabilization of single metal atoms is a persistent challenge in heterogeneous catalysis. Especially supported late transitions metals are prone to undergo agglomeration to nanoparticles under reducing conditions. In this study, nitrogen‐rich covalent triazine frameworks (CTFs) are used to immobilize iridium complexes. Upon reduction at 400 °C, immobilized Ir(acac)(COD) on CTF does not form nanoparticles but transforms into a highly active Ir single atom catalyst. The resulting catalyst systems outperforms both the immobilized complex and supported nanoparticles in the dehydrogenation of formic acid as probe reaction. This superior performance could be traced back to decisive changes of the coordination geometry positively influencing activity, selectivity and stability. Spectroscopic analysis reveals an increase of electron density on the cationic iridium site by donation from the CTF macroligand after removal of the organic ligand sphere from the Ir(acac)(COD) precursor complex upon reductive treatment. This work demonstrates the ability of nitrogen moieties to stabilize molecular metal species against agglomeration and opens avenues for catalysts design using isolated sites in high‐temperature applications under reducing atmosphere. [ABSTRACT FROM AUTHOR]

A template-free pyrolysis approach is proposed to fabricate nitrogen and sulfur doped hollow mesoporous carbon sphere (N/S-HMCS). The unique hollow/mesoporous nanostructure and abundant N, S-doped active sites prompt the optimal N/S-HMCS 900 exhibits satisfactory electrocatalysis in oxygen electroreduction for high-performance Zn-air battery. [Display omitted] • A nitrogen, sulfur dual-doped hollow mesoporous carbon sphere (N/S-HMCS) is fabricated by a simple yet efficient template-free pyrolysis approach. • The N/S-HMCS 900 exhibits high oxygen reduction reaction (ORR) activities with an excellent half-wave potential and high methanol tolerance. • The optimal electrocatalyst can be used as air electrode materials in high-performance zinc-air batteries. • Density functional theory (DFT) calculations reveal that N, S-dual dopant can create extra active sites with higher catalytic activity than the isolated N -dopant. The construction of hollow mesoporous carbon nanospheres (HMCS) avoiding the use of traditional soft/hard templates is highly desired for nanoscience yet challenging. Herein, we report a simple and straightforward template-free strategy for preparing nitrogen, sulfur dual-doped HMCSs (N/S-HMCSs) as oxygen reduction reaction (ORR) electrocatalysts. The unique hollow spherical and mesoporous structure was in-situ formed via a thermally initiated hollowing pathway from an elaborately engineered covalent triazine framework. Regulation of pyrolysis temperatures contributed to precisely tailoring of the shell thickness of HMCSs. The resulting N/S-HMCS 900 (pyrolyzed at 900 °C) possessed high N and S contents, large specific surface areas, rich and uniform mesopores distribution. Consequently, as a metal-free ORR electrocatalyst, N/S-HMCS 900 exhibits a high half-wave potential, excellent methanol tolerance and great long-term durability. Additionally, density functional theory calculations demonstrate that N, S-dual dopant can create extra active sites with higher catalytic activity than the isolated N -dopant. This strategy provides new insights into the construction of hollow and mesoporous multi-heteroatom-doped carbon materials with tunable nanoarchitecture for various electrochemical applications. [ABSTRACT FROM AUTHOR]

The high crystalline covalent triazine framework-1 (CTF-1), composed of alternating triazine and phenylene, has emerged as an efficient photocatalyst for solar-driven hydrogen evolution reaction (HER). However, it is of great challenge to further improve photocatalytic HER performance via increasing crystallinity due to its near-perfect crystallization. Herein, an alternative strategy of scaffold functionalization is employed to optimize the energy band structure of crystalline CTF-1 for boosting hydrogen-evolving activity. Guided by the computational predictions, versatile CTF-based polymer photocatalysts are prepared with different functional groups (OH, NH 2 , COOH) using binary polymerization for practical hydrogen production. Experiment evidence verifies that the introduction of a limited number of electron-donating groups is sufficient to maintain high crystallinity in CTF, modulate the band structure, broaden visible light absorption, and consequently enhance its photophysical properties. Notably, the functionalization with OH exhibits the most positive effect on CTF-1, delivering a photocatalytic activity with a hydrogen-producing rate exceeding 100 µmol h -1 ., (© 2024 Wiley‐VCH GmbH.)

Perfluorinated covalent triazine frameworks (F‐CTFs) have shown unique features and attractive performance in separation and catalysis. However, state‐of‐the‐art F‐CTFs synthesized via the ZnCl2‐promoted procedure have quite low fluorine contents due to C−F bond cleavage induced by chloride (a Lewis base) and the harsh conditions deployed (400–700 °C). Fabricating F‐CTFs with high fluorine contents (>30 wt %) remains challenging. Herein, we present a low‐temperature ionothermal approach (275 °C) to prepare F‐CTFs, which is achieved via polymerization of tetrafluoroterephthalonitrile (TFPN) over the Lewis superacids, e.g., zinc triflimide [Zn(NTf2)2] without side reactions. With low catalyst loading (equimolar), F‐CTFs are afforded with high fluorine content (31 wt %), surface area up to 367 m2 g−1, and micropores around 1.1 nm. The highly hydrophobic F‐CTF‐1 exhibits good capability to boost electroreduction of CO2 to CO, with faradaic efficiency of 95.7 % at −0.8 V and high current density (−141 mA cm−2) surpassing most of the metal‐free electrocatalysts. [ABSTRACT FROM AUTHOR]

Ultrathin nanosheets have great potential for photocatalytic applications, however, suffer from enlarged band gap and narrowed visible‐light‐responsive range due to the quantum confinement effect. Herein, we report a novel redox strategy for efficient preparation of ultrathin crystalline amide‐functionalized covalent‐triazine‐framework nanosheets (CTF NSs) with enhanced visible light absorption. The CTF NSs exhibited photocatalytic hydrogen (512.3 μmol h−1) and oxygen (12.37 μmol h−1) evolution rates much higher than that of pristine bulk CTF. Photocatalytic overall water splitting could be achieved with efficient stoichiometric H2 (5.13 μmol h−1) and O2 (2.53 μmol h−1) evolution rates under visible light irradiation. Experimental and theoretical analysis revealed that introduction of amide groups as electron donor optimized the band structure and improve its visible‐light absorption, hydrophilicity and carrier separation efficiency, thus resulting in the enhanced photocatalytic performance. The well‐dispersed CTF NSs could be easily cast onto a support as a thin film device and demonstrate excellent photocatalytic activity (25.7 mmol h−1 m−2 for hydrogen evolution). [ABSTRACT FROM AUTHOR]

The development of a simple and efficient methanol-resistant membrane strategy is of great significance for improvement of the performance of fuel cells, making it an attractive and challenging topic. In this work, sulfonated covalent triazine framework (SCTF) nanosheets are prepared by a micro-interface method and post-sulfonation, which show excellent dispersion in polar solutions, such as water and N , N -Dimethylacetamide (DMAc). Then a series of composite proton exchange membranes (SCTF-x@SPP- co -PAEKs) are prepared by blending these SCTF nanosheets with sulfonated micro-block copolymers (SPP- co -PAEKs) resin. The results show that the appropriate addition of SCTF can significantly improve the proton conductivity (PC), methanol resistance and fuel cell performance of the prepared composite membrane, which can be attributed to the good interfacial compatibility between the SCTF nanosheets and the sulfonated micro-block copolymer matrix. The passive direct methanol fuel cells (DMFCs) with SCTF-x@SPP-3 membrane exhibit power density in the range of 28.0–33.3 mW cm−2 at 25 °C, which is superior to the related values of the pristine membrane and the commercial Nafion® series membranes. [Display omitted] • SCTF nanosheets were prepared by a micro-interface method and post-sulfonation. • SCTF nanosheets showed excellent dispersion in polar solutions, such as H 2 O and DMAc. • Composite PEMs were prepared by blending SCTF nanosheets with sulfonated polymers. • Good interfacial compatibility made composite PEMs have good performance. [ABSTRACT FROM AUTHOR]