Latest ArticlesLead-free hybrid double perovskites (LFHDPs) have received a lot of attention due to their environmental friendliness and promising attributes. However, studying the effect of film thickness on LFHDPs optoelectronic properties has not yet been investigated. Herein, we synthesized two new Ruddlesden–Popper LFHDPs, namely (C5H12N)4AgBiI8 (CAB-1) and (C6H14N)4AgBiI8 (CAB-2) using cyclopentylamine and cyclohexylamine as monoamine ligands. Indeed, these two Ag(Ⅰ)-Bi(Ⅲ) LFHDPs form smooth and uniform films ranging in thickness from 250 nm to 1 µm, with preferred orientations. Notably, the studies on the optical properties showed that the direct band gap value decreased from 2.17 eV to 1.91 eV for CAB-1 and from 2.05 eV to 1.86 eV for CAB-2 with increasing thickness. Accordingly, photo-current response using a xenon lamp revealed a significant difference of over 1000 nA between light and dark conditions for 1 µm-thickness films, suggesting potential for light harvesting. Other than that, thicker films of CAB-1 and CAB-2 exhibit high stability for 90 days in a relatively humid environment (RH of 55%), paving the way for promising optoelectronic applications.
Maintaining high metal dispersion of supported metal catalysts to achieve superior reactivity under harsh conditions poses one of the main challenges for their practical applications. Constructing and regulating the strong metal-support interactions (SMSI) by diverse methodologies has emerged as one of the promising approaches to fabricating robust supported metal catalysts. In this study, we report an L-ascorbic acid (AA)-inducing strategy to generate SMSI on a titania-supported gold (Au) catalyst after high-temperature treatment in an inert atmosphere (600 ℃, N2). The AA-induced SMSI can efficiently stabilize Au nanoparticles (NPs) and preserve their catalytic performance. The detailed study reveals that the key to realizing this SMSI is the generation of oxygen vacancies within the TiO2 support induced by the adsorbed AA, which drives the formation of the TiOx permeable layer onto the Au NPs. The strategy could be extended to TiO2-supported Au catalysts with different crystal phases and platinum group metals, such as Pt, Pd, and Rh. This work offers a promising novel route to design stable and efficient supported noble metal catalysts by constructing SMSI using simple reducing organic adsorbent.
Using different external stimuli to control interfacial friction, rather than just pursuing low friction, is a highly attractive research regime due to its economic and scientific importance. One option to achieve such a goal is to use external stimuli that modulate the energy dissipation pathways. In particular, electric stimuli such as surface potential has gained remarkable interest for two reasons: Electrotunable friction has the potential for real-time, in situ manipulation of friction, and external electric stimuli is relatively easy to apply and to remove for reversible change. In this review, we explore the emerging research area of electrotunable friction mainly under the boundary lubrication situation, when the contacting surfaces are separated by a molecularly thin layer, reviewing typical achievements from experiments using electrochemical atomic force microscopy and modified surface force balances, as well as molecular dynamics simulations. Additionally, we explore the theoretical and practical challenges that may need to be tackled in the future.
The design and synthesis of a novel π-conjugated fluorescent framework by external ligand-assisted C−H olefination of heterocycles with excellent regioselectivity and broad substrate scope are reported herein. These novel fluorescent materials could present full-color-tunable emissions with large Stokes shifts. Furthermore, the protocol provides an opportunity to rapidly screen novel organic single-molecule white-light materials with high fluorescence quantum yields. The robust organic and low-cost white light-emitting diodes could rapidly be fabricated using the white-light-emitting material. Experimental data and theoretical calculations indicate that in the white-light dual emission the relatively short wavelength from high-lying singlet state emission and the relatively long wavelength from low-lying singlet state emission. The anti-Kasha dual-emission systems will provide a foundation for the development and application of organic single-molecule white light materials, effectively promoting the development and innovation of luminescent materials. In addition, this method demonstrated its potential application in the synthesis of new near-infrared (NIR) fluorescence materials with large Stokes shifts based on the olefination of heterocycles.
The occurrence, development, and metastasis of tumors often entail abnormal expression of genetic substances. Monitoring and regulating changes in intracellular nucleic acid substances hold promise for achieving accurate tumor diagnosis and effective treatment. However, the effectiveness of integrated tumor diagnosis and treatment based on functional nucleic acids still needs to be improved. In this study, we engineered a multifunctional nucleic acid delivery system grounded in a cationic covalent organic framework carrier. This system not only showcases effective gene silencing but also boasts high sensitivity in detecting miR21 levels within tumor cells, enabling real-time monitoring of tumor gene therapy efficacy. The construction of this integrated functional nucleic acid delivery platform provides new ideas for precise tumor detection and effective tumor treatment.
The hydration state of amphiphilic block copolymers during the self-assembly transition is closely related to the structure and properties of copolymers. In this study, the temperature-induced self-assembly of copolymer poly(N,N-dimethylacrylamide)-poly(diacetone acrylamide) (PDMAA30-PDAAM60)2 in aqueous solution was monitored by near-infrared spectroscopy with water as a probe. The wavelet packet transform was employed to improve the spectral resolution. The spectral information of hydrated water surrounding the hydrophilic PDMAA and hydrophobic PDAAM blocks was then extracted, revealing the significant roles of water in morphological transition of the copolymer from spherical to worm-like micelles. Specifically, water molecules interacting with N atoms and C=O groups of the hydrophilic block gradually decrease during the morphological transition, while hydrogen-bond structures NH-CO of the hydrophobic block gradually break, bringing more water molecules into contact with the hydrophobic block. This work provides a foundation for exploring the role of water molecules during the self-assembly transition of complex block copolymers.
ZnIn2S4, a typical n-type semiconductor, has received intensive attention due to its suitable bandgap, excellent visible light absorption performance, and simple and flexible preparation methods. However, its application is curbed by photo-generated carrier recombination and photo corrosion. Although constructing S-scheme heterojunctions by combining ZnIn2S4 with other semiconductors can solve these problems, the photocatalytic activity of S-scheme heterojunctions can be further improved. Therefore, this short review summarizes modification strategies of ZnIn2S4-based S-scheme heterojunctions. This article also introduces the concept, design principles, and characterization methods of ZnIn2S4-based S-scheme heterojunction. Finally, current challenges and future research focuses related to ZnIn2S4-based S-scheme heterojunctions are discussed and summarized, including the utilization of advanced in-situ characterization techniques to further illuminate the photocatalytic mechanism, the DFT-assisted design of catalysts to increase the selectivity of products during photocatalytic CO2 reduction, and extending the photo-response of ZnIn2S4-based S-scheme heterojunction to near-infrared range, etc.
Wound healing in diabetic patients presents significant challenges due to heightened risks of bacterial infection, elevated glucose levels, and insufficient angiogenesis. Nanozymes are widely employed for wound healing, but most current nanozyme systems exhibit only moderate activity limited by incompatible reaction microenvironments including pH and hydrogen peroxide (H2O2) concentration. Herein, a glucose-activated nanozyme hydrogel was developed using bovine serum albumin (BSA)-modified gold nanoparticles (Au NPs) attached to a two-dimensional (2D) metal-organic framework (MOF) (Cu-TCPP(Fe)@Au@BSA) by an in situ growth method. The Au NPs function as a glucose oxidase (GOx)-like enzyme, converting glucose to gluconic acid and H2O2, triggering the peroxidase (POD)-like activity of Cu-TCPP(Fe) to produce hydroxyl radicals (•OH), effectively eliminating bacteria. Additionally, the modification of BSA reduces the Au NP size, enhancing enzyme activity. Both in vitro and in vivo tests demonstrate that this nanozyme hydrogel can be activated by the microenvironment to lower blood glucose, eliminate bacterial infections, and promote epithelial formation and collagen deposition, thus accelerating diabetic wound healing effectively. The multifunctional nanozyme hydrogel dressing developed in this study presents a promising therapeutic approach to enhance diabetic wound healing.
Pt(Ⅱ)−salophen complexes (S-1~S-4) and 9,10-diphenylanthracene (DPA) tethering pillar[5]arene derivatives (A-1 and A-2) were synthesized to act as sensitizers and annihilators for triplet-triplet annihilation upconversion (TTA-UC), respectively. It turned out that the pyridine cation served as a mask for the excited state of the sensitizer, the triplet states of S-2 and S-3 were significantly quenched by photo-induced electron transfer (PET) with phosphorescence quantum yield quenched from 24.4% for S-4 to 9.3% for S-3, and therefore, both S-2 and S-3 led to negligible UC emissions when traditional annihilator DPA was used as the annihilator. Delightfully, when supramolecular annihilator A-1 and A-2 were employed to include the pyridine cation, PET was significantly inhibited and the triplet states of the sensitizers were activated, TTA-UC emission was therefore boosted. The UC quantum yield of A-2/S-3 system was up to 130 times higher than that of DPA/S-3 system, and the UC emission was switchable by the addition of competitive guests.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
