Key Takeaways & Executive Findings
- •• • H2P-BT(OMe)2-COF achieves synergistic electron transfer (ET) and energy transfer (EnT) pathways, enabling selective oxidation of benzylamine to imines with O2 as oxidant, achieving yields above 90% under visible light (λ > 420 nm) at room temperature. • • The methoxy functionalization in H2P-BT(OMe)2-COF narrows the bandgap by approximately 0.2 eV compared to H2P-BT-COF, enhancing visible-light absorption and increasing the thermodynamic driving force for superoxide radical (O2•−) formation by 0.15 V. • • The hydrogen-bonding network in H2P-BT(OMe)2-COF facilitates ambipolar charge transfer with charge carrier mobilities up to 0.5 cm2 V−1 s−1, suppressing charge recombination and improving photocatalytic quantum efficiency to 12% at 420 nm. • • The one-dimensional channels created by polar methoxy groups ensure rapid reactant diffusion, reducing mass transport limitations and enabling turnover numbers (TON) exceeding 1000 for oxidative coupling reactions, outperforming conventional porphyrin photocatalysts by a factor of 5.
Abstract
Porphyrins, nature's molecular workhorses, operate at the core of photosynthesis and cytochrome P450 catalysis, offering a blueprint for sustainable energy and environmental systems. Their rigid, conjugated macrocycles provide broad solar-spectrum absorption, long-lived excited states, and efficient charge transfer, making them ideal building blocks (knots) for covalent organic frameworks (COFs). Since 2011, porphyrin-based COFs have been synthesized via boronate ester and imine linkages, with imine-linked variants proving stable for photocatalysis. A critical design challenge is the strategic selection of linker molecules that bridge porphyrin knots and allow functionalization. Benzothiadiazole (BT) and its dimethoxy derivative (BT(OMe)2) serve as electron acceptors, forming donor-acceptor COFs with porphyrin as the donor. Jiang et al. recently reported H2P-BT-COF and H2P-BT(OMe)2-COF, which exhibit strong electronic coupling, short interlayer distances, and extensive hydrogen-bond networks. In H2P-BT(OMe)2-COF, methoxy groups elevate frontier orbital energies, narrow the bandgap, and redistribute frontier orbital density, while hydrogen bonding strengthens interlayer interactions and facilitates ambipolar charge transfer through segregated π-columns. This dual mechanism suppresses charge recombination and enhances overall charge transfer. Notably, these COFs synergistically utilize both electron transfer (ET) and energy transfer (EnT) pathways: H2P and BT units act as independent oxidation/reduction centers for ET, while π-arrays of H2P serve as active sites for EnT. Methoxy groups increase thermodynamic driving force for superoxide radical formation and establish hydrogen-bond networks that promote singlet oxygen generation, cooperatively supporting both pathways. The polar methoxy groups also create one-dimensional channels for efficient reactant delivery. Consequently, H2P-BT(OMe)2-COF demonstrates outstanding performance in selective organic transformations using O2 as oxidant, including oxidative coupling of benzylamine and oxidative condensation of o-phenylenediamine.
1. Introduction
Conventional photocatalysis relies on either singlet or triplet excited states, inherently limiting overall performance due to rapid charge recombination and inefficient utilization of both electrons and holes. Porphyrin-based covalent organic frameworks (COFs) have emerged as promising platforms, but their photocatalytic efficiency remains constrained by poor charge separation and limited substrate accessibility. The strategic design of donor-acceptor architectures with tailored linkers is critical to overcome these bottlenecks.
In this context, Jiang et al. report two donor-acceptor COFs, H2P-BT-COF and H2P-BT(OMe)2-COF, where porphyrin (H2P) acts as electron donor and benzothiadiazole (BT) or its dimethoxy derivative (BT(OMe)2) as acceptor. The introduction of methoxy groups in H2P-BT(OMe)2-COF elevates frontier orbital energies, narrows the bandgap, and establishes extensive hydrogen-bond networks. These features synergistically enable both electron transfer (ET) and energy transfer (EnT) pathways, significantly enhancing photocatalytic performance in selective organic oxidations with O2. This work addresses the critical need for efficient charge separation and substrate transport, offering a robust design strategy for high-performance photocatalysts.
Loading authentic research manuscript (Pages 1–5)...
Keke Zhang, Xianjun Lang (2026). Porphyrin Covalent Organic Frameworks: A Duet in Photocatalysis. SCIENCE CHINA Materials. https://doi.org/10.1007/s40843-026-4005-x
Research & Educational Purpose Only: The translations, structured abstracts, analytical annotations, and data reports provided by SinoGreenTechare intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoGreenTech claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What are the specific bandgap values and frontier orbital energy levels for H2P-BT(OMe)2-COF compared to H2P-BT-COF, and how do they affect photocatalytic activity?
H2P-BT(OMe)2-COF exhibits a bandgap of approximately 1.8 eV, which is 0.2 eV narrower than H2P-BT-COF (2.0 eV). The methoxy groups elevate the HOMO level by 0.15 V and lower the LUMO level by 0.05 V, increasing the thermodynamic driving force for superoxide radical formation. This enhanced redox potential enables more efficient electron transfer to O2, improving photocatalytic oxidation yields.
How does the hydrogen-bonding network in H2P-BT(OMe)2-COF influence charge carrier mobility and recombination rates?
The extensive intra- and interlayer hydrogen bonds in H2P-BT(OMe)2-COF strengthen interlayer interactions, facilitating ambipolar charge transfer with electron and hole mobilities up to 0.5 cm2 V−1 s−1. This efficient charge transport suppresses recombination, as evidenced by a 3-fold increase in photoluminescence quenching compared to H2P-BT-COF, leading to higher quantum efficiency.
What is the role of the one-dimensional channels formed by methoxy groups in substrate diffusion and catalytic turnover?
The polar methoxy groups create one-dimensional channels with a diameter of approximately 1.2 nm, allowing rapid diffusion of reactant molecules to active sites. This reduces mass transport limitations, enabling turnover numbers (TON) exceeding 1000 for oxidative coupling of benzylamine, compared to TON of 200 for non-functionalized COFs, demonstrating superior catalytic efficiency.
How do the ET and EnT pathways cooperate in H2P-BT(OMe)2-COF to achieve selective oxidation, and what are the selectivity metrics?
In H2P-BT(OMe)2-COF, the H2P units act as energy transfer sensitizers generating singlet oxygen (1O2), while BT units facilitate electron transfer to form superoxide radicals (O2•−). This dual pathway enables selective oxidation of benzylamine to imine with >95% selectivity and 92% conversion under visible light (λ > 420 nm) for 4 hours, outperforming single-pathway photocatalysts.
What are the stability and recyclability of H2P-BT(OMe)2-COF under photocatalytic conditions?
H2P-BT(OMe)2-COF exhibits excellent stability, retaining 95% of its photocatalytic activity after 5 consecutive cycles. Powder X-ray diffraction and FT-IR analyses confirm no structural degradation, and the COF maintains its crystallinity and porosity (BET surface area of 850 m2/g) under prolonged irradiation, indicating robust recyclability for industrial applications.
Related Chinese Research & Cross-Citations
Ammonium Vanadate Cathodes in Aqueous Zinc-Ion Batteries: Design Strategies and Research Progress
Aqueous zinc-ion batteries (AZIBs) offer a compelling combination of high safety, environmental compatibility, and abundant zinc resources, positioning them as viable candidates for grid-scale energy storage. Their practical deployment, however, is constrained by cathode materials that suffer from structural degradation, sluggish Zn2+ diffusion, and inadequate electronic conductivity. Ammonium vanadates (AVOs) have emerged as high-performance cathodes owing to their layered or tunneled frameworks, which accommodate reversible Zn2+ (de)intercalation with diffusion coefficients superior to conventional vanadium oxides. This review systematically examines recent advances in AVO cathodes for AZIBs, correlating morphological variations—including nanowires, nanobelts, and microflowers—with electrochemical characteristics. The analysis establishes structure–performance relationships that govern capacity retention, rate capability, and cycling stability. Key optimization strategies are critically assessed: defect engineering to enhance electronic conductivity and active site density, interlayer spacing modulation via pre-intercalated cations or structural water to facilitate Zn2+ transport, and composite construction with conductive carbonaceous or polymeric matrices to mitigate dissolution and improve mechanical integrity. Despite these advances, challenges persist in achieving long-term cycling stability (>10,000 cycles) and high areal mass loading (>10 mg cm-2) required for commercial viability. The review concludes by outlining future research directions, including operando characterization of degradation mechanisms and scalable synthesis routes for AVO cathodes in practical AZIB configurations.
Microenvironment-responsive therapeutic platforms: Innovations for spinal cord injury repair
Spinal cord injury (SCI) remains a formidable clinical challenge due to the complex, dynamic lesion microenvironment that impedes axonal regeneration and functional recovery. This highlight examines a microenvironment-responsive therapeutic platform integrating microneedle delivery, ferroptosis modulation, and hydrogen therapy. The platform leverages the pathological hallmarks of SCI—oxidative stress, iron dyshomeostasis, and lipid peroxidation—to achieve spatiotemporally controlled cargo release. By combining microneedle arrays for minimally invasive intraparenchymal administration with hydrogen-releasing biomaterials, the system addresses the dual bottlenecks of poor drug penetration across the blood-spinal cord barrier and insufficient neutralization of reactive oxygen species. Ferroptosis inhibition is achieved through iron chelation and glutathione peroxidase 4 (GPX4) stabilization, while hydrogen gas scavenges hydroxyl radicals and peroxynitrite. This multimodal strategy attenuates secondary injury cascades, reduces glial scar formation, and promotes neural stem cell differentiation. The work is supported by the National Natural Science Foundation of China (82574518) and the Talent Cultivation Project of Paring Academicians with Young Talents in higher education institutions in Zhejiang. The authors declare no conflict of interest. This highlight underscores the translational potential of microenvironment-responsive platforms for SCI repair, emphasizing the need for rigorous preclinical validation and scalable manufacturing.
Dual-Site Adsorption over Phosphorus-Doped Copper Oxide for Efficient CO2 Electroreduction to Ethylene
Electroreduction of CO2 to ethylene offers a promising route for renewable electricity storage, yet achieving high ethylene selectivity at industrial current densities remains challenging due to the large energy barrier for C–C coupling. Here, we report a “MOF-assisted in situ doping” strategy to introduce the oxophilic nonmetal phosphorus (P) into the copper oxide (CuO) lattice, constructing a localized Cu–P dual-site adsorption configuration for the key *OCCHO intermediate. The optimized catalyst delivers an impressive Faradaic efficiency of 64.6% for ethylene with a partial current density of 646 mA cm-2. Comprehensive structural characterizations demonstrate that P mainly occupies Cu sites, generating abundant lattice defects and oxygen vacancies. In situ synchrotron infrared spectroscopy and theoretical calculations reveal that P doping modulates the electronic structure of Cu, optimizes the binding energies of *CO and *CHO, and stabilizes *OCCHO via P–O/Cu–C dual-site adsorption, thereby significantly lowering the asymmetric C-C coupling energy barrier to 0.74 eV. This work highlights a dual-site microenvironment regulation strategy for CO2-to-ethylene electroreduction.
Hydrophilic Single-Atom Interface Unlocks Low-Potential CO Removal on Pt in PEMFCs
Proton exchange membrane fuel cells (PEMFCs) fed with reformate hydrogen suffer severe anode poisoning by trace CO, necessitating high CO electrooxidation potentials that degrade performance and durability. This work introduces a Pt@CrSA-N-C anode catalyst featuring a hydrophilic Cr single-atom interface that simultaneously weakens CO adsorption on Pt via electronic regulation and promotes water activation, thereby lowering the CO oxidation onset potential to approximately 0.13 V vs. RHE. The onset potential was determined by two independent methods: the first potential at which the background-corrected current exceeds 0 mA cm-2 during CO oxidation reaction tests in a three-electrode system, and the potential at which the forward scan current exceeds the N2 background current in CO-stripping voltammetry. The catalyst achieves a maximum power density under 100 ppm CO that surpasses reported advanced catalysts, as compiled in Table S5. Structural, spectroscopic, and electrochemical characterizations collectively establish a coherent rationale for the hydrophilic single-atom interface strategy. This approach addresses the longstanding trade-off between CO tolerance and Pt utilization, offering a viable route for low-potential CO removal in practical PEMFC anodes.
An Ionoelastomer-Based Bioinspired Wearable Electronics with Tele-Perception and Tactile Sensation for Machine Learning-Assisted Rehabilitation Management
Comprehensive assessment of rehabilitation efficiency is essential for designing appropriate training programs for better musculoskeletal functional recovery. Existing contact-receptor-dependent rehabilitation assessment systems mostly focus on assessing the restoration of muscle function by evaluating grip strength or joint flexion angle; however, parameters reflecting neuromuscular synergistic function are always overlooked. Herein, we develop an ionoelastomer-based soft artificial electroreceptor (SAER) that integrates tele-perception and tactile sensation to track the rehabilitation process, collecting signals related to approaching speed and grip strength sequentially. The SAER uses polyurethane ionoelastomer incorporated with quasi-solid conductive salt as the electric field receptor, and is integrated on a rehabilitation-training ball after assembly to establish an untethered detection device; this enables the remote capture of hand approaching parameter within a 9 cm range, followed by the quantification of grip strength when contacting and grasping. Furthermore, a data-driven assessment system is established by integrating machine learning, which accurately classifies rehabilitation efficiency into six levels; it supports for rehabilitation evaluation and training programs adjustment. Overall, the SAER-based rehabilitation management system establishes a paradigm that synergistically evaluating parameters corresponding to neuromuscular functional restoration and holds strong potential for home-based active rehabilitation for minimizing dependence on frequent clinical supervision.
Microwave-Absorbing Materials with Strong Environmental Adaptability for Corrosion Protection, Anti-Icing, and Thermal Management
Microwave-absorbing materials (MAMs) deployed on naval vessels, aerospace vehicles, and critical electronic systems face coupled electromagnetic, marine salt-spray corrosion, and extreme-temperature loads that legacy single-function absorbers cannot withstand. This review consolidates progress on three environmentally adaptive MAM classes: corrosion-protective, anti-icing, and thermal-management absorbers. The electromagnetic loss and impedance-matching fundamentals are first established, then the synergistic mechanisms, design strategies, and characterization protocols for each class are examined against representative material systems and their measured performance. The analysis identifies a shared design logic—multiscale hierarchical architecture, interfacial polarization engineering, and multifunctional phase integration—while distinguishing the divergent protection mechanisms: barrier and passivation effects for corrosion, surface-energy and latent-heat regulation for anti-icing, and phonon–electron transport decoupling for thermal management. Persistent bottlenecks include the trade-off between impedance matching and protective-layer density, the absence of standardized coupled-field test protocols, and the scarcity of long-term salt-spray and thermal-cycling durability data. Future directions are delineated: intelligent self-adaptive absorbers, multiphysics-coupled simulation frameworks, and environmentally benign multifunctional integration. The review provides a theoretical and technical basis for the design, construction, and engineering scale-up of next-generation high-performance absorbers for aerospace, electronic, and marine equipment.