Latest ArticlesBroadband photothermal and photoacoustic agents in the near-infrared (NIR) biowindow are of significance for cancer phototheranostics. In this work, PtCu nanosheets with an average lateral size of less than 10 nm are synthesized as NIR photothermal and photoacoustic agents in vivo, which show strong light absorption from NIR-Ⅰ to NIR-Ⅱ biowindows with the photothermal conversion efficiencies of 20.4% under 808 nm laser and 32.7% under 1064 nm laser. PtCu nanosheets functionalized with folic acid-modified thiol-poly(ethylene glycol) (SH-PEG-FA) present good biocompatibility and 4T1 tumor-targeted effect, which give high-contrast photoacoustic imaging and efficient photothermal ablation of 4T1 tumor in both NIR-Ⅰ and NIR-Ⅱ biowindows. Our work significantly broadens applications of noble metal-based nanomaterials in the fields of cancer phototheranostics by rationally designing their structures and modulating their physicochemical properties.
Single-molecule junctions are building blocks for constructing molecular devices. However, intermolecular interactions like winding bring additional interference among the surrounding molecules, which inhibits the intrinsic coherent transport through single-molecule junctions. Here, we employed a nanocavity (dimethoxypillar[5]arene, DMP[5]), which is analogous to electric cables, to confine the conformation of flexible chains (1,8-diaminooctane, DAO) via host-guest interaction. Single-molecule conductance measurements indicate that the conductance of DAO encapsulated with DMP[5] is as high as that of pure DAO, as reproduced by theoretical simulations. Intriguingly, the molecular lengths of the DAO encapsulated with DMP[5] increase from 1.13 nm to 1.46 nm compared with the pure DAO, indicating that DMP[5] keeps DAO upright-standing via the confinement effect. This work provides a new strategy to decouple the intermolecular interaction by employing an insulating sheath, enabling the high-density integration of single-molecule devices.
Rapid carrier recombination and slow charge transfer dynamics have significantly reduced the performance of photocatalytic hydrogen production. Construction of heterojunctions via utilizing the sulfur-edge and metal-edge sites of metal sulfide semiconductor for improving photocatalytic activity remains a significant challenge. Herein, a novel ZnIn2S4/MnS S-scheme heterojunction was prepared by hydrothermal synthesis to accelerate charge carrier transfer for efficient photocatalysis. Notably, ZnIn2S4/MnS exhibited excellent photocatalytic hydrogen evolution activity (7.95 mmol g−1 h−1) under visible light irradiation (≥420 nm), up to 4.7 times higher than that of pure ZnIn2S4. Additionally, cycling experiments showed that ZM-2 remained high stability after four cycles. Density-functional theory (DFT) calculations and in situ XPS results confirm the formation of S-scheme heterojunction, indicating that the tight interfacial contact between ZnIn2S4 and MnS with the presence of Mn-S bonds (the unsaturated Mn edges of MnS and the uncoordinated S atoms in the edge of ZnIn2S4) promoted faster charge transfer. Besides, the unsaturated S atom on the surface of MnS is an active site with strong H+ binding ability, which can effectively reduce the overpotential or activation barrier for hydrogen evolution. This study illustrates the critical influence of the interfacial Mn-S bond on the ZnIn2S4/MnS S-scheme heterojunction to achieve efficient photocatalytic hydrogen production and provides relevant guidance for carrying out rational structural/interfacial modulation.
Enhancing the corrosion resistance of carriers within Fenton-like systems and inhibiting the migration and aggregation of single atoms in reaction environments are essential for maintaining both high activity and stability at catalytic sites, thus meeting fundamental requirements for practical application. The Fenton-like process of activating various strong oxidants by silicon-based single atom catalysts (SACs) prepared based on silicon-based materials (mesoporous silica, silicon-based minerals, and organosilicon materials) has unique advantages such as structural stability (especially important under strong oxidation conditions) and environmental protection. In this paper, the preparation strategies for the silicon-based SACs were assessed first, and the structural characteristics of various silicon-based SACs are systematically discussed, their application process and mechanism in Fenton-like process to achieve water purification are investigated, and the progress of Fenton-like process in density functional theory (DFT) of silicon-based derived single atom catalysts is summarized. In this paper, the preparation strategies and applications of silicon-based derived SACs are analyzed in depth, and their oxidation activities and pathways to different pollutants in water are reviewed. In addition, this paper also summarizes the device design and application of silicon-based derived SACs, and prospects the future development of silicon-based SACs in Fenton-like applications.
Recently, CsPbBr3 perovskite solar cells (PSCs) have garnered attention due to cost-effectiveness and reliability. However, hole transport limitations lead to charge recombination and lower power conversion efficiency (PCE). Defects in the CsPbBr3 layer, poor hole transport at the interface with carbon electrodes, and energy level differences hinder performance. Optimizing the perovskite layer using electron-donating organic molecules containing -NH2 groups enhances efficiency and stability by passivating defects and modulating lattice structure. In this work, tetra(4-aminophenyl)ethylene (TPE) and tetra(4-aminobiphenyl)ethylene (TPE-Ph) were employed to optimize the CsPbBr3/carbon electrode interface. Their strong electron-donating properties and amino groups facilitate hole transfer and defect passivation, boosting PCE to 9.38% and enhancing stability.
Aryl-ether bonds are facile to attack by oxidizing radicals, thus stimulating the exploitation of ether-free polymers as proton exchange membranes (PEMs) for the long-lasting operation of fuel cells. In this study, a novel class of PEMs derived from all-carbon fluorinated backbone polymers containing sulfide-linked alkyl sulfonic acid side chains have been developed through a straightforward and effective synthetic procedure. The sulfide-linked alkyl sulfonate groups were tethered to the poly(triphenylene pentafluorophenyl) backbone through a quantified and site-specific para-fluoro-thiol click reaction. Owing to the existence of obvious phase separation morphology between hydrophobic main chain and hydrophilic sulfonate groups in the side chains, resulting PEMs demonstrated favorable proton conductivity of 142.5 mS/cm at 80 ℃, while maintaining excellent dimensional stability with an in-plane swelling ratio of <17% as well as a through-plane swelling ratio of <25%. They also exhibit elevated thermal decomposition temperatures (Td5% exceeding 300 ℃) alongside high tensile strength (>50 MPa). Furthermore, the ether-free full-carbon fluorinated main chain and the -S- group in the side chain, which serves as an effective free-radical scavenger, providing good chemical stability during Fenton's test. The PEMs achieved a maximum power density of 407 mW/cm2 in a single H2/air fuel cell, and an open-circuit voltage decline rate of 0.275 mV/h in a durability test at 30% RH and 80 ℃. Concurrently, the hydrogen crossover current density is only 1/3 of that of Nafion 212. These findings reveal that the resulted PEMs display considerable antioxidative properties along with commendable performance, with prospective applications in proton exchange membrane fuel cells.