限域化学：碳基功能材料从基础研究到应用

限域化学研究的是对象在纳米尺度限域空间内的化学行为。限域空间内的化学环境不同于常规本体溶液,因而会出现许多奇特的现象,如反应选择性增强、活性增加、稳定性提高。本文结合笔者课题组近年来的工作,对限域化学领域碳基功能材料的限域策略,包括限域界面诱导、限域化学组装印刷及三维多孔受限体系作简要介绍,并阐述了其在催化、储能方面的应用。最后提出了限域化学未来发展面临的主要挑战,期望能为此领域研究提供参考。     

Controllable Preparation of Branched Polyolefins with Various Microstructural Units via Chain-walking Ethylene and Pentene Polymerizations

Chinese Journal of Polymer Science - Branched polyolefins with controllable topology structures were generated from the chain-walking (co)polymerizations of ethylene, 1-pentene (1P) and 2-pentene...     

Plasmon-Enhanced Electrochemiluminescence at the Single-Nanoparticle Level

Plasmon-enhanced electrochemiluminescence (ECL) at the single-nanoparticle (NP) level was investigated by ECL microscopy. The Au NPs were assembled into an ordered array, providing a high-throughput platform that can easily locate each NP in sequential characterizations. A strong dependence of ECL intensity on Au NP configurations was observed. We demonstrate for the first time that at the single-particle level, the ECL of Ru(bpy)₃²⁺-TPrA was majorly quenched by small Au NPs (<40 nm), while enhanced by large Au ones (>80 nm) due to the localized surface plasmon resonance (LSPR). Notably, the ECL intensity was further increased by the coupling effect of neighboring Au NPs. Finite Difference Time Domain (FDTD) simulations conformed well with the experimental results. This plasmon enhanced ECL microscopy for arrayed single NPs provides a reliable tool for screening electrocatalytic activity at a single particle.     

Photoinduced Reaction of α-Bromoacetophenone with Thiosulfonate: Synthesis of β-Keto Thiosulfone

A photoinduced synthesis of β-keto thiosulfone/β-keto selenosulfone by the reaction of α-bromoacetophenone with thiosulfonate/selenosulfonate under metal-free and visible light irradiation conditions is developed. Two C−S bonds or one C−S bond and one C−Se bond were constructed simultaneously.     

A Strong-Acid-Resistant [Th6] Cluster-Based Framework for Effectively and Size-Selectively Catalyzing Reductive Amination of Aldehydes with N,N-Dimethylformamide

Utilization of N,N-dimethylformamide (DMF) as an amine source and reductant for synthesizing tertiary amines is a promising way to replace the substrates formaldehyde and dimethylamine, and it is desirable to seek porous acid-resistant catalysts for heterogeneous catalysis of this reaction. Herein, a robust metal–organic framework (MOF) {[Th₆O₄(OH)₄(H₂O)₆(BCP)₃]⋅10 DMF}_n ( 1 ) containing stacked nanocages with a diameter of 1.55 nm was constructed. Compound 1 can maintain its single-crystal structure even kept in air at 400 °C for 3 h, and in DMF or water at 200 °C for 7 days. Density functional theory (DFT) calculations suggested that the high interaction energy between the [Th₆O₄(OH)₄(H₂O)₆]¹²⁺ clusters and ligands was responsible for the excellent stability of 1 . Catalytic investigations revealed that 1 can effectively and size-selectively catalyze the reductive amination of aldehydes with DMF, and it can be reused at least five times without obvious loss in catalytic activity.     

Two-dimensional Supramolecular Polymers Based on Selectively Recognized Aromatic Cation-π and Donor-Acceptor Motifs for Photocatalytic Hydrogen Evolution

Two-dimensional (2D) organic polymers have recently received considerable interest, especially those whose architectures are held together via supramolecular engineering. However, current approaches toward supramolecular 2D structures usually suffer from mutual interference of noncovalent interactions and lack of intrinsic functions. Herein, we report well-regulated 2D supramolecular polymers (2DSPs) through an aromatics-selective recognition strategy of cation-π and donor-acceptor (D-A) motifs, which are derived from C₄-symmetric cationic monomers and electron-withdrawing molecules. By subtly designing the strength and direction of noncovalent driving forces, the mutual interference between cation-π and D-A interactions is effectively avoided, enabling the construction of 2DSPs in aqueous solution. On this basis, the resultant 2DSPs possess boosted photocatalytic hydrogen evolution activity at a rate of 600 μmol g⁻¹ h⁻¹, which is mainly ascribed to the specific stacking mode of cation-π/D-A motifs and the ordered 2D structures.     

Unraveling the Oxidation Behaviors of MXenes in Aqueous Systems by Active-Learning-Potential Molecular-Dynamics Simulation

MXenes are 2D materials with great potential in various applications. However, the degradation of MXenes in humid environments has become a main obstacle in their practical use. Here we combine deep neural networks and an active learning scheme to develop a neural network potential (NNP) for aqueous MXene systems with ab initio precision but low cost. The oxidation behaviors of super large aqueous MXene systems are investigated systematically at nanosecond timescales for the first time. The oxidation process of MXenes is clearly displayed at the atomic level. Free protons and oxides greatly inhibit subsequent oxidation reactions, leading to the degree of oxidation of MXenes to exponentially decay with time, which is consistent with the oxidation rate of MXenes measured experimentally. Importantly, this computational study represents the first exploration of the kinetic process of oxidation of super-sized aqueous MXene systems. It opens a promising avenue for the future development of effective protection strategies aimed at controlling the stability of MXenes.     

Efficient Near-Infrared Electroluminescence from Lanthanide-Doped Perovskite Quantum Cutters

Perovskite nanocrystals (PeNCs) deliver size- and composition-tunable luminescence of high efficiency and color purity in the visible range. However, attaining efficient electroluminescence (EL) in the near-infrared (NIR) region from PeNCs is challenging, limiting their potential applications. Here we demonstrate a highly efficient NIR light-emitting diode (LED) by doping ytterbium ions into a PeNCs host (Yb³⁺ : PeNCs), extending the EL wavelengths toward 1000 nm, which is achieved through a direct sensitization of Yb³⁺ ions by the PeNC host. Efficient quantum-cutting processes enable high photoluminescence quantum yields (PLQYs) of up to 126 % from the Yb³⁺ : PeNCs. Through halide-composition engineering and surface passivation to improve both PLQY and charge-transport balance, we demonstrate an efficient NIR LED with a peak external quantum efficiency of 7.7 % at a central wavelength of 990 nm, representing the most efficient perovskite-based LEDs with emission wavelengths beyond 850 nm.     

A DNA Origami-based Bactericide for Efficient Healing of Infected Wounds

Bacteria infection is a significant obstacle in the clinical treatment of exposed wounds facing widespread pathogens. Herein, we report a DNA origami-based bactericide for efficient anti-infection therapy of infected wounds in vivo. In our design, abundant DNAzymes (G4/hemin) can be precisely organized on the DNA origami for controllable generation of reactive oxygen species (ROS) to break bacterial membranes. After the destruction of the membrane, broad-spectrum antibiotic levofloxacin (LEV, loaded in the DNA origami through interaction with DNA duplex) can be easily delivered into the bacteria for successful sterilization. With the incorporation of DNA aptamer targeting bacterial peptidoglycan, the DNA origami-based bactericide can achieve targeted and combined antibacterial therapy for efficiently promoting the healing of infected wounds. This tailored DNA origami-based nanoplatform provides a new strategy for the treatment of infectious diseases in vivo.     

Simple high-performance liquid chromatography-ultraviolet method for simultaneous separation and detection of 14 bisphenol pollutants in building materials

A high-performance liquid chromatography-ultraviolet method was developed for rapidly and simultaneously analyzing novel and typical bisphenols in building materials, including bisphenol S, diphenolic acid, bisphenol F, bisphenol E, bisphenol A, bisphenol B, bisphenol AF, bisphenol AP, bisphenol C, bisphenol FL, bisphenol Z, bisphenol BP, bisphenol M, and bisphenol P. By using a Kromasil 100–5 C18 column, these bisphenols were completely separated in 40 min via gradually increasing the concentration of methanol in the mobile phase from 45 to 80% during the elution process. In particular, this method achieved the synchronous analysis of bisphenol S, diphenolic acid, bisphenol FL, bisphenol BP, and bisphenol M through HPLC, which were difficult to separate and had to be identified and detected through mass spectrometry. The limits of detection of the method ranged from 0.002 to 0.040 mg/L for these 14 bisphenols, with a precision of less than 4.9% (n = 7, c = 0.05 mg/L). The analytical results for five types of building materials (phenolic, epoxy, polycarbonate, polyester, and polysulfone resins) indicated that the proposed method is appropriated for the rapid measurement of bisphenols in real samples.