阿拉丁SCI论文搜索工具

Photocatalysis has unprecedently prevailed in the removal of pollutants and the artificial photosynthesis of H 2 O 2. However, inefficient surface reaction and exciton dissociation rate are the main hurdles in arriving at high photocatalytic performance. A versatile strategy for improving surface reactions between the photocatalyst and the reactant and the charge separation dynamics is in pressing need. Herein, post-quaternization of the conjugated microporous polymer (CMP) is proposed. This not only converts the CMP from hydrophobic to hydrophilic but also evidently improves charge separation and mobility due to the polarizing effect. Most importantly, because of the quaternization, the surface reactions can be pronouncedly strengthened due to both the improved dispersity and lowering of O 2 adsorption energy. As a result, the CMPs serve both photodegradation and photosynthesis of H 2 O 2 , with iB-TDZ exhibiting pronounced enhancement in the photodegradation of 100 ppm of Congo red and 2,4-D in 40 min and 90 min, respectively, transcending the vast majority of the reported photocatalysts, while the production of H 2 O 2 reaches 2.922 mmol g −1 in three-hour irradiation. As a proof-of-concept experiment, simultaneous photodegradation of 2,4-D and photocatalytic H 2 O 2 production is realized. It was found that 2,4-D can boost photocatalytic H 2 O 2 production from 1.92 mmol g −1 (without 2,4-D) to 3.25 mmol g −1 within 90 min, likely due to its role in providing protons and serving as an h + scavenger. These findings provide a fresh platform for the design of CMP-based photocatalysts for simultaneous photocatalytic wastewater treatment and H 2 O 2 production. 相关产品

Fingerprint recognition plays a crucial role due to its uniqueness. However, conventional detection methods suffer from significant drawbacks, including high consumption, health risk and sample contamination, which restrict their practical application in the crime investigations and forensic analysis. This necessitates the development of simple, rapid, safe and environmentally-friendly alternative methods for fingerprints detection. In this work, we report the synthesis of novel cyan-emitting carbon dots (CDs) via a facile one-step hydrothermal reaction using polyethyleneimine and coumarin as precursors. The CDs enabled the clear visualization of fingerprint patterns on various substrates through immersion and spraying methods with pure water solutions, without the need for any cosolvents. Level 2 and level 3 details of fingermarks were evidently visible for individual identification within a short exposure time under 365 nm UV light irradiation. Additionally, fluorescent 3D fingerprint images revealed direct and specific evidence regarding pressing habits. Interestingly, the fluorescence intensity of CDs was tunable by adjusting the pH. We further fabricated invisible CDs ink for information encryption and decryption via UV irradiation and acid/alkali treatment. Moreover, CDs have the specific ability to sense Fe 3+ ions in actual water samples, with a detection limit of 0.613 μM and a linear range of 0–27 μM. We conducted an in-depth study on the fluorescence quenching mechanism of CDs caused by Fe 3+ ions, proposing a plausible mechanism based on a synergistic effect of dynamic quenching, static quenching and inner filter effect. Therefore, this study provides a promising multifunctional nanomaterial for fingerprint recognition, data encryption, and Fe 3+ detection. 相关产品

High-quality repair of critical bone defects without exogenous cells remains a major clinical challenge worldwide. Herein, we fabricated a nanocomposite hydrogel scaffold (ASA/MSNs/CSH) by incorporating aspirin (ASA)-loaded mesoporous silica nanoparticles (MSNs) into genipin-cross-linked chitosan hydrochloride (CSH). The resulting scaffold was designed to provide immunomodulatory support during the process of bone regeneration. ASA-loaded MSNs were encapsulated in CSH, forming a composite hydrogel capable of sustained drug release for over 35 days. This composite hydrogel was able to meet key criteria for physicochemical properties, mechanical strength, biocompatibility, and cell affinity. The study showed that the scaffolds could create a beneficial immune microenvironment through reducing inflammation and inducing macrophages toward M2-polarized phenotype in vitro. The scaffold also enhanced the osteogenesis of bone marrow mesenchymal stromal cells, as demonstrated by enhancing the alkaline phosphatase activity and the formation of calcium nodules. Meanwhile, the TGF-β/Smad pathway was identified as an important regulatory mechanism via Western blot analysis. Moreover, the critical size defect models were established in rat skulls, and the results demonstrated that the ASA/MSNs/CSH nanocomposite scaffolds exhibited adequate biocompatibility, superior anti-inflammatory effect, and an admirable capacity for bone regeneration in vivo. 相关产品

The eco-friendly and efficient nanofiltration (NF) membrane plays a critical role in the water purification industry; however, improving permeance while maintaining rejection remains a tremendous challenge. This study presents a novel approach for regulating interfacial polymerization (IP) by intercalating sodium alginate (SA) into MXene nanosheets. This method facilitates the fabrication of nanofiltration membranes that effectively overcome the “trade-off” effect. In addition to increasing the penetration area by enlarging the interlayer spacing between MXene nanosheets, the use of SA also reduces the susceptibility to swelling caused by weak interactions among adjacent stacked nanosheets.   The presence of the intermediate layer effectively regulates the diffusion of piperazine and promotes the formation of a complete polyamide (PA) layer with ridge-valley structures, while simultaneously enhancing permeability. The permeability of the prepared nanofiltration membrane reaches 32.4 L m -2 h −1 bar −1 while retaining a rejection efficiency of 96.3 % for divalent ions. This research paves the way for the development of a new generation of high-flux nanofiltration membranes used in desalination and water purification. 相关产品

In this study, the refractive index of epoxy resin was adjusted according to the mixing ratio of two types of curing agents, namely 4,4′-diaminodiphenylmethane and poly(propylene glycol) bis(2-aminopropyl ether). The optical properties of the cured pure polymers and transparent glass fiber-reinforced plastics (GFRP) 1 (analyzed with an ultraviolet–visible spectrophotometer) were compared. Epoxy (EP)/P9D1-F exhibited excellent optical properties (transmittance of 89.54 % and a haze of 9.30 %). The small refractive index difference between EP/P9D1 and glass fiber reduced the phase delay and fabricated high-transmittance, transparent GFRP. In addition, EP/P9D1-F exhibited superior mechanical properties, with enhanced flexural strength and fracture toughness owing to the improved stress distribution between the fiber and matrix. These findings suggest that a transparent GFRP with high transmittance and glass-like optical properties, as well as excellent mechanical performance, can be fabricated by appropriately mixing and adjusting two or more types of curing agents. 相关产品

Nanofibrillated cellulose paper (nanopaper) has drawn increasing attention as a potential material for various areas, due to its extremely smooth surface, excellent optical transparency and sequent nanofiber matrix. To extend nanopaper application as the analytical platform, nanopaper-based microfluidics has quickly advanced recently. However, the current method of patterning microchannels on nanopaper which is the basic for establishing microfluidic (i.e., 3D printing and spray coating), still has some limitations, including low precision and long preparation time. So, in this study, we utilized laser cutting to fabricate microchannel patterns on nanopaper by burning the surface of nanopaper. Through systematic parameters (laser cutting speed and power) optimization, we identified the optimal laser cutting conditions, enhancing both efficiency and accuracy. The minimum depth and width of the microchannels were reduced to 15 μm and 58 μm, respectively. The entire fabrication process, including drying, was completed in less than 35 minutes. Compared to the existing methods, this method has smaller microchannels size, time saving and no need for additional molds or equipment those advantages which contribute its novelty and accuracy. By arranging different shapes of lines, microchannels for various sensing were developed. As a proof-of-concept, we developed two functional nanopaper-based analyzer devices (NanoPADs). With a detection limit of 2.2 mM for glucose and 281 fM for Rhodamine B (RhB), both demonstrating excellent performance and low detection limits. The results indicate that our laser-cutting nanopaper microchannels may serve as a platform for developing high-performance analytical devices which may spark the development of nanopaper in the future. 相关产品

The gut bacteria not only play a crucial role in maintaining human health but also exhibit close associations with the occurrence of numerous diseases. Understanding the physiological and pathological functions of gut bacteria and enabling early diagnosis of gut diseases heavily relies on accurate knowledge about their in vivo distribution. Consequently, there is a significant demand for noninvasive imaging techniques capable of providing real-time localization information regarding gut bacteria. In this work, we developed a second near-infrared (NIR-II) fluorescent nanoprobe labeling-based visualization strategy for real-time tracking of the biodistribution of Gram-negative bacteria in the gastrointestinal tract of mice. By utilizing positively charged silver sulfide quantum dots (Ag2S QDs) as NIR-II nanoprobes and exploiting electrostatic interactions to efficiently label the Gram-negative probiotic Escherichia coli Nissle 1917 with negative surface charges, we have achieved rapid and effective labeling. Leveraging the exceptional NIR-II fluorescent performance of Ag2S QDs, our approach enables high spatiotemporal resolution visualization via NIR-II imaging in mouse gastrointestinal areas where Ag2S QD-labeled probiotics are present, facilitating real-time in vivo tracking capabilities for these labeled probiotics. This work not only establishes a powerful intestinal bacterial imaging strategy but also introduces novel concepts for constructing nanomaterial-bacteria hybrid systems. 相关产品

This study successfully synthesized a novel photocatalyst, a composite of silicon carbide and graphitic carbon nitride, which achieved efficient photocatalytic reduction of uranium (VI) under visible light irradiation. The optimal loading of silicon carbide in the composite was determined to be SiC 15 @g-C 3 N 4 , which significantly enhanced the optoelectronic properties of graphitic carbon nitride, improving the separation efficiency of photogenerated electron-hole pairs and extending the electron lifetime from 1.73 ns to 3.96 ns. Furthermore, the adding of silicon carbide effectively modified the band structure of graphitic carbon nitride, with the conduction band position shifting from −0.74 eV to −1.18 eV, thereby enhancing the reducibility. In photocatalytic reduction experiments, the SiC 15 @g-C 3 N 4 composite demonstrated exceptional reduction efficiency, achieving a remarkable 100 % photocatalytic reduction rate within 30 min, which is significantly superior to that of pristine g-C 3 N 4 . The study revealed that superoxide radicals (·O 2 - ) are the main reactive species in the reaction, leading to the formation of uraninite (UO 2 ) as the reduced product. These findings not only deepen the understanding of the synergistic effects between SiC and g-C 3 N 4 but also provide new perspectives for the design of efficient photocatalysts. The SiC 15 @g-C 3 N 4 composite shows potential applications in environmental remediation and nuclear waste management. 相关产品

The management of chronic infected wounds remains a significant clinical challenge, largely due to the deficiency of optimal wound dressings with adequate mechanical strength, appropriate adhesiveness, and efficient sustainable antibacterial, reactive oxygen species (ROS) scavenging, pro-angiogenesis, and immunomodulation properties. To address such a dilemma, we employed a simple and facile strategy to utilize resveratrol (RSV) as a functional component to mediate hydrogel gelation in this study. The structure of this obtained hydrogel was supported by a multibond network, which not only endowed the resultant product with superior mechanical strength and moderate adhesiveness but also effectively prolonged the bioavailability of RSV. This strategy successfully integrated the entire system with sustainable antibacterial, ROS scavenging, pro-angiogenesis, and immunomodulation properties. Subsequent in vivo evidence has verified that this material was capable to accelerate the healing of chronic infected wounds. The underlying mechanism can be explained that this hydrogel is capable of propelling macrophage polarization from the M1 to M2 phenotype through modulating the PI3K/AKT signaling pathway to activate the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling as well as maintaining the mitochondrial membrane potential level in the normal state under excessive inflammatory and oxidative stimulus. In summary, this multifunctional hydrogel wound dressing provides a feasible way to promote the bioavailability of RSV, which is conducive for preparing a promising candidate for chronic infected wound healing. What is more important, it is also beneficial to reveal the correlative mechanisms to establish advanced therapeutic platform for targeting other complex infection microenvironment. 相关产品

Although transparent paper derived from cellulose has been successfully demonstrated as an inexpensive, renewable and biodegradable substrate used for flexible electronics, the inherently stiff characteristic and intrinsic poor conductivity of the cellulose paper inevitably hinders its application in stretchable electronic devices. Herein, we report a new avenue for construction of highly stretchable, transparent, and ionic conductive cellulose gel paper via glycerol inducing plasticizing and CaCl 2 initiating chelating, a facile casting and drying strategy. The renewable carboxymethyl cellulose is employed for its intrinsically abundant carboxyl groups for crosslinking with Ca 2+ via ionic coordination bonds, benefiting the improvement of various performances. The resultant cellulose ionic gel paper (CIGP) displays high stretchability (tensile strain 320 % and strength 978 kPa at fracture), and transparency (over 90 % in 400 nm to 780 nm wavelength). In addition, the CIGP also has high ionic conductivity (82.78 mS/m), and displays highly reliable, sensitive and wide range strain sensing abilities to various stimuli. Significantly, the transparent CIGP with excellent sensing performances has been successfully integrated into multifunctional sensors and optoelectronic device, showing broad applications in flexible electronics. 相关产品

Metal-supported solid oxide fuel cells (MS-SOFCs) exert a critical influence on achieving efficient energy utilization and promoting global sustainable development, due to their high mechanical strength, low costs, and reliable stack sealing. However, traditional fabrication methods for MS-SOFCs are relatively complex, involving high temperature sintering of electrodes and metal supports, which can lead to grain growth and oxidation of the metal support. Herein, a fabrication process is proposed for MS-SOFCs using a directly assembled method where the electrode-metal co-sintering process is not necessary. The directly assembled interfaces are activated and bonded by applying polarization currents. The single cell exhibits a maximum power density of 0.79 W cm −2 at 800 °C and demonstrates superior operational stability at 750 °C. The findings shed new light on the rational fabrication of MS-SOFCs through the introduction of a directly assembled method. 相关产品

Rapid and efficient separation of dyes from water is a formidable challenge due to the trade-off between separation selectivity and permeability. Here, a novel superhydrophilic copper foam (CF) enabling the rapid and efficient filtration of cationic dyes from water is reported. The fabrication involves brushing a coating consisting of attapulgite (APT), poly(vinyl alcohol) (PVA), TiO 2 and glutaraldehyde (GA) onto copper foam and then heating. The obtained copper foam (CF-PVA/GA@APT/TiO 2 ) is superhydrophilic and negatively charged with dye adsorption capability. The interconnected cage-shaped porous structure endows the foam with long tortuous permeation channels and large pore size. It is able to separate various cationic dyes with a separation efficiency reaching to 99.93 % and a permeation flux up to 1671 ± 189 L m -2 h −1 under gravity. Furthermore, the CF-PVA/GA@APT/TiO 2 can realize the selective separation and recovery of various cationic dyes from rhodamine B (RhB)-mixed dye solutions. Molecular dynamics-based computational modeling and experimental studies revealed that the interaction energy between the surface of CF-PVA/GA@APT/TiO 2 and methylene blue (MB) is much stronger than that of the former and RhB, leading to adsorption of MB in the permeation channel, while RhB gradually migrates through the permeation channel and passes through the channel with water. The tortuous permeation channels of CF-PVA/GA@APT/TiO 2 increase the contact area and absorption opportunities for cationic dye molecules on the surface, and its large pore size maintains the filtration flux. These properties provide the as-prepared foam with excellent potential applicability for industrial dye wastewater treatment. 相关产品