Search

Covalent organic frameworks (COFs) with stable crystalline porous structures and flexible assembly properties contribute to the direct photocatalytic synthesis of H2O2 to meet the growing global demand. To address the challenges of insufficient redox capacity and photogenerated carrier recombination of COFs, S‐scheme heterojunction is constructed from COFs with quantum dots (QDs) to improve the photocatalytic production of H2O2. Herein, 0D ZnCdS QDs (ZCS) uniformly anchor on the surface of a 2D conjugated tetrathiafulvalene‐based COF (TT‐COF), affording the S‐scheme heterojunction TT‐COF/ZCS. Formation of S‐scheme heterojunction effectively prevents the agglomeration of ZCS, modulates the energy band structure of TT‐COF, and enhances the migration of photogenerated carriers and redox ability. As a total consequence, the optimized heterojunction (TZ‐40) is able to afford H2O2 in the yield up to 5171 µmol g−1 h−1 under visible light irradiation with H2O and O2, much higher than those for TT‐COF, 2520 µmol g−1 h−1, and ZCS, 2647 µmol g−1 h−1. The present result demonstrates the great potential of COFs/QDs‐based S‐scheme heterojunctions for photocatalytic applications including photocatalytic H2O2 production. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of porphyrin center regulated three‐dimensional covalent organic frameworks (COFs) with 2‐fold interpenetrated scu or sqc topology have been investigated. These COFs exhibit unique structural features and properties, making them promising candidates for photocatalytic applications in CO2 reduction and artemisinin synthesis. The porphyrin center serves as an anchor for metal ions, allowing precise control over structures and functions of the frameworks. Furthermore, the metal coordination within the framework imparts desirable catalytic properties, enabling their potential use in photocatalytic reactions. Overall, these porphyrin center regulated metal‐controlled COFs offer exciting opportunities for the development of advanced materials with tailored functionalities. [ABSTRACT FROM AUTHOR]

Assemblies that mimic natural lipid bilayers are theoretically efficient for photocatalytic CO2 reduction; however, such an approach has not been yet explored. Herein, metallogels (LG/Nico‐Co) based on the co‐assembly of L‐glutamic acid lipid (LG/Nico) and cobalt ions exhibited excellent photocatalytic CO2 reduction, with 208 724 μmol g−1 CO production within 24 h and 90 % CO/H2 selectivity, or 166 826 μmol g−1 CO production within 12 h and 46 % CO/H2 selectivity, depending on the water content of the solvent. The alkyl chains of LG/Nico provide a hydrophobic microenvironment for efficient gas transfer, and the assembled bilayers induce a synergistic effect between two adjacent Co ions for catalyzing the CO2 reduction reaction. These architectures present new alternatives for the development of highly efficient photocatalytic soft matter based on the assembly of small amphiphilic molecules. [ABSTRACT FROM AUTHOR]

Upconversion nanoparticles (UCNPs) have been used as building blocks in the construction of multimodal contrast agents for theranostics, that is, the combination of diagnostics and therapies. Upconversion luminescence (UCL) imaging is widely used for cell and tissue imaging while magnetic resonance imaging (MRI) is well-suited for in vivo imaging. Photothermal therapy (PTT) using (near-infrared) NIR laser radiation constitutes a minimally invasive alternative to the conventional surgical treatment of cancer. As such, multifunctional Mn-complex modified NaDyF4:Yb@NaLuF4:Yb,Er@polydopamine (PDA) nanocomposites (Dy@Lu@PDA–Mn) were synthesized, which was based on the fact that Yb3+ and Er3+ induce UCL, Dy3+ and Mn2+ interferes with T2 and T1 in MRI, and PDA strongly absorbs in the NIR region for PTT. Through tri-modal UCL, T1-, T2-weighted MRI guiding, an outstanding photothermal therapeutic efficacy with tumour elimination was obtained in a mice breast cancer model, by injection of Dy@Lu@PDA–Mn upon laser irradiation. A strategy for multimodal imaging-guided PTT was formulated and the potential of multifunctional nanostructures for use in cancer theranostics was demonstrated. [ABSTRACT FROM AUTHOR]

Fabricating COFs-based electrocatalysts with high stability and conductivity still remains a great challenge. Herein, 2D polyimide-linked phthalocyanine COF (denoted as NiPc-OH-COF) is constructed via solvothermal reaction between tetraanhydrides of 2,3,9,10,16,17,23,24-octacarboxyphthalocyaninato nickel(II) and 2,5-diamino-1,4-benzenediol (DB) with other two analogous 2D COFs (denoted as NiPc-OMe-COF and NiPc-H-COF) synthesized for reference. In comparison with NiPc-OMe-COF and NiPc-H-COF, NiPc-OH-COF exhibits enhanced stability, particularly in strong NaOH solvent and high conductivity of 1.5 × 10 -3  S m -1 due to the incorporation of additional strong interlayer hydrogen bonding interaction between the O-H of DB and the hydroxy "O" atom of DB in adjacent layers. This in turn endows the NiPc-OH-COF electrode with ultrahigh CO 2 -to-CO faradaic efficiency (almost 100%) in a wide potential range from -0.7 to -1.1 V versus reversible hydrogen electrode (RHE), a large partial CO current density of -39.2 mA cm -2 at -1.1 V versus RHE, and high turnover number as well as turnover frequency, amounting to 45 000 and 0.76 S -1 at -0.80 V versus RHE during 12 h lasting measurement., (© 2024 Wiley‐VCH GmbH.)

The synthesis and characterization of porphyrin center regulated three-dimensional covalent organic frameworks (COFs) with 2-fold interpenetrated scu or sqc topology have been investigated. These COFs exhibit unique structural features and properties, making them promising candidates for photocatalytic applications in CO 2 reduction and artemisinin synthesis. The porphyrin center serves as an anchor for metal ions, allowing precise control over structures and functions of the frameworks. Furthermore, the metal coordination within the framework imparts desirable catalytic properties, enabling their potential use in photocatalytic reactions. Overall, these porphyrin center regulated metal-controlled COFs offer exciting opportunities for the development of advanced materials with tailored functionalities., (© 2024 Wiley-VCH GmbH.)

Assemblies that mimic natural lipid bilayers are theoretically efficient for photocatalytic CO 2 reduction; however, such an approach has not been yet explored. Herein, metallogels (LG/Nico-Co) based on the co-assembly of L-glutamic acid lipid (LG/Nico) and cobalt ions exhibited excellent photocatalytic CO 2 reduction, with 208 724 μmol g -1 CO production within 24 h and 90 % CO/H 2 selectivity, or 166 826 μmol g -1 CO production within 12 h and 46 % CO/H 2 selectivity, depending on the water content of the solvent. The alkyl chains of LG/Nico provide a hydrophobic microenvironment for efficient gas transfer, and the assembled bilayers induce a synergistic effect between two adjacent Co ions for catalyzing the CO 2 reduction reaction. These architectures present new alternatives for the development of highly efficient photocatalytic soft matter based on the assembly of small amphiphilic molecules., (© 2022 Wiley-VCH GmbH.)

Upconversion nanoparticles (UCNPs) have been used as building blocks in the construction of multimodal contrast agents for theranostics, that is, the combination of diagnostics and therapies. Upconversion luminescence (UCL) imaging is widely used for cell and tissue imaging while magnetic resonance imaging (MRI) is well-suited for in vivo imaging. Photothermal therapy (PTT) using (near-infrared) NIR laser radiation constitutes a minimally invasive alternative to the conventional surgical treatment of cancer. As such, multifunctional Mn-complex modified NaDyF 4 :Yb@NaLuF 4 :Yb,Er@polydopamine (PDA) nanocomposites (Dy@Lu@PDA-Mn) were synthesized, which was based on the fact that Yb 3+ and Er 3+ induce UCL, Dy 3+ and Mn 2+ interferes with T 2 and T 1 in MRI, and PDA strongly absorbs in the NIR region for PTT. Through tri-modal UCL, T 1 -, T 2 -weighted MRI guiding, an outstanding photothermal therapeutic efficacy with tumour elimination was obtained in a mice breast cancer model, by injection of Dy@Lu@PDA-Mn upon laser irradiation. A strategy for multimodal imaging-guided PTT was formulated and the potential of multifunctional nanostructures for use in cancer theranostics was demonstrated.