Latest ArticlesHerein, we fabricate an embedding structure at the interface between Pt nanoparticles (NPs) and CeO2-{100} nanocubes with surface defect sites (CeO2-SDS) through quenching and gas bubbling-assisted membrane reduction methods. The in-situ substitution of Pt NPs for atomic-layer Ce lattice significantly increases the amount of reactive oxygen species from 133.68 µmol/g to 199.44 µmol/g. As a result, the distinctive geometric structure of Pt/CeO2-SDS catalyst substantially improves the catalytic activity and stability for soot oxidation compared with the catalyst with no quenching process, i.e., its T50 and TOF values are 332 ℃ and 2.915 h-1, respectively. Combined with the results of experimental investigations and density functional theory calculations, it is unveiled that the unique embedding structure of Pt/CeO2-SDS catalyst can facilitate significantly electron transfer from Pt to the CeO2-{100} support, and induce the formation of interfacial [Ce-Ox-Pt2] bond chains, which plays a crucial role in enhancing the key step of soot oxidation through the dual activation of surface lattice oxygen and molecular O2. Such a fundamental revelation of the interfacial electronic transmission and corresponding modification strategy contributes a novel opportunity to develop high-efficient and stable noble metal catalysts at the atomic level.
A phenylphenothiazine anchored Tb(Ⅲ)-cyclen complex PTP-Cy-Tb for hypochlorite ion (ClO−) detection has been designed and prepared. PTP-Cy-Tb shows a weak Tb-based emission with AIE-characteristics in aqueous solutions. After addition of ClO−, the fluorescence of PTP-Cy-Tb gives a large enhancement for oxidization the thioether to sulfoxide group. The detection limit of PTP-Cy-Tb toward ClO− is as low as 8.85 nmol/L. The sensing mechanism was detailedly investigated by time of flight mass spectrometer (TOF-MS), Fourier transform infrared spectroscopy (FT-IR) and density functional theory (DFT) calculation. In addition, PTP-Cy-Tb has been successfully used for on-site and real-time detection of ClO− in real water samples by using the smartphone-based visualization method and test strips.
In this study, we proposed a novel and efficient way to strengthen polyvinyl alcohol (PVA) fiber using graphene quantum dots (GQDs). PVA molecular chains were grafted onto the surface of GQDs through Friedel-Crafts alkylation reaction to obtain functionalized GQDs (f-GQDs), and PVA/f-GQDs composite fiber was successfully prepared by wet spinning and post-treatment. The tensile strength and Young’s modulus of the composite fiber reached up to 1229.24 MPa and 35.36 GPa which were approximately twice and 4 times those of the pure PVA fiber, respectively. Moreover, the composite fiber was demonstrated excellent resistance to solvents. In addition, the PVA/f-GQDs composite fiber showed intense and uniform cyan fluorescence, meanwhile, it could maintain stable solid-state fluorescence in acid and alkali solutions and particularly after long-term immersion in water (1 month). This study proposes a promising route for obtaining high-performance conventional fibers with some new functions.
Carbon dots (CDs), due to their low cost, high stability, and high luminous efficiency, have emerged as an excellent material for the emissive layer in next-generation electroluminescent light-emitting diodes (ELEDs). However, improving the efficiency of fluorescent CDs-based ELEDs remains challenging, primarily because it is difficult to utilize triplet excitons in the electroluminescence process. Therefore, enhancing the exciton utilization efficiency of CDs during electroluminescence is crucial. Based on this, we exploited the characteristic large exciton binding energy commonly found in CDs to develop exciton-emitting CDs. These CDs facilitate the radiative recombination of excitons during electroluminescence, thereby improving the electroluminescent efficiency. By rationally selecting precursors, we developed high quantum efficiency CDs and subsequently constructed CDs-based ELEDs. The blue-light device exhibited an external quantum efficiency of over 4%. This study introduces a novel design concept for CDs, providing a new strategy for developing high-performance blue ELEDs based on CDs.
Pyridyl-based ketones and 1, 6-diketones are both attractive and invaluable scaffolds which play pivotal roles in the construction and structural modification of a plethora of synthetically paramount natural products, pharmaceuticals, organic materials and fine chemicals. In this context, we herein demonstrate an unprecedented, robust and generally applicable synthetically strategy to deliver these two crucial ketone frameworks via visible-light-induced ring-opening coupling reactions of cycloalcohols with vinylazaarenes and enones, respectively. A plausible mechanism involves the selective β-C-C bond cleavage of cycloalcohols enabled by proton-coupled electron transfer and ensuing Giese-type addition followed by single electron reduction and protonation. The synthetic methodology exhibits broad substrate scope, excellent functional group compatibility as well as operational simplicity and environmental friendliness.
Ln-containing polyoxoniobates (PONbs) have appealing applications in luminescence, information encryption and magnetic fields, but the synthesis of PONbs containing high-nuclearity Ln-O clusters is challenging due to the easy hydrolysis of Ln3+ ions in alkaline environments. In this paper, we are able to integrate CO32− and high-nuclearity Ln-O clusters into PONb to construct an inorganic giant Eu19-embedded PONb H49K16Na13(H2O)63[Eu21O2(OH)7(H2O)5(Nb7O22)10(Nb2O6)2(CO3)18]·91H2O (1), which contains the highest nuclearity Eu-O clusters and the largest number of Eu3+ ions among PONbs. In addition, the film that was prepared by mixing 1 with gelatin and glycerol, exhibits reversible luminescence switching behavior under acid/alkali stimulation and has been used to create a fluorescence-encoded information approach. This work paves a feasible strategy for the construction of high-nuclearity Ln-O cluster-containing PONbs and the expansion of the application of Ln-containing PONbs in information encryption.
Up to now, numerous emerging methods of cancer treatment including chemodynamic therapy, photothermal therapy, photodynamic therapy, sonodynamic therapy, immunotherapy and chemotherapy have rapidly entered a new stage of development. However, the single treatment mode is often constrained by the complex tumor microenvironment. Recently, the nanomaterials and nanomedicine have emerged as promising avenues to overcome the limitation in cancer theranostics. Especially, metal-organic frameworks (MOFs) have gained considerable interests in cancer therapy because of their customizable morphologies, easy functionalization, large specific surface area, and good biocompatibility. Among these MOFs, iron-based MOFs (Fe-MOFs) are particularly promising for cancer treatment due to their properties as nano-photosensitizers, peroxidase-like activity, bioimaging contrast capabilities, and biodegradability. Utilizing their structural regularity and synthetic tunability, Fe-MOFs can be engineered to incorporate organic molecules or other inorganic nanoparticles, thereby creating multifunctional nanoplatforms for single or combined theranostic modes. Herein, the minireview focuses on the recent advancements of the Fe-MOFs-based nanoplatforms for self-enhanced imaging and treatment at tumor sites. Furthermore, the clinical research development of Fe-MOFs-based nanoplatforms is discussed, addressing key challenges and innovations for the future. Our review aims to provide novice researchers with a foundational understanding of advanced cancer theranostic modes and promote their clinical applications through the modification of Fe-MOFs.
In this paper, low-temperature dielectric-blocked discharge plasma (DBD) was employed for the first time to treat silica-doped H4PMo11VO40 (HPAV) catalysts (DBD(Ar/x)-MF-Catal) and apply them in the catalytic methacrolein (MAL) selective oxidation to produce methacrylic acid (MAA). This work investigates in detail the controllable regulation of the concentration of oxidation states on silica-doped HPAV catalysts by adjusting the DBD discharge with controlled changes in voltage, current, treatment time, and treatment medium. It reports the intrinsic correlation between oxidation states and MAL oxidation performance. The research results indicated that the catalytic performance was related to the presence of oxygen vacancies and oxygen species (VO2+), and are the main reason for the selective oxidation of MAL to MAA. Besides, the generation of oxygen vacancies and VO2+ altered localized electrons, which resulted in the easier activation of O2. Theoretical calculations of DFT also proved the formation mechanism of oxygen vacancies and VO2+ and electron properties on high-performance polymers, which elucidated the intrinsic influence of catalyst components. The DBD(Ar/10)-MF-Catal catalysts with suitable VO2+ and oxygen vacancy concentrations exhibited the highest catalytic performance with 90% MAL conversion and 70% MAA selectivity and showed good stability (500 h).
The detrimental phase transformations of sodium layered transition metal oxides (NaxTMO2) during desodiation/sodiation seriously suppress their practical applications for sodium ion batteries (SIBs). Undoubtedly, comprehensively investigating of the dynamic crystal structure evolutions of NaxTMO2 associating with Na ions extraction/intercalation and then deeply understanding of the relationships between electrochemical performances and phase structures drawing support from advanced characterization techniques are indispensable. In-situ high-energy X-ray diffraction (HEXRD), a powerful technology to distinguish the crystal structure of electrode materials, has been widely used to identify the phase evolutions of NaxTMO2 and then profoundly revealed the electrochemical reaction processes. In this review, we begin with the descriptions of synchrotron characterization techniques and then present the advantages of synchrotron X-ray diffraction (XRD) over conventional XRD in detail. The optimizations of structural stability and electrochemical properties for P2-, O3-, and P2/O3-type NaxTMO2 cathodes through single/dual-site substitution, high-entropy design, phase composition regulation, and surface engineering are summarized. The dynamic crystal structure evolutions of NaxTMO2 polytypes during Na ion extraction/intercalation as well as corresponding structural enhancement mechanisms characterizing by means of HEXRD are concluded. The interior relationships between structure/component of NaxTMO2 polytypes and their electrochemical properties are discussed. Finally, we look forward the research directions and issues in the route to improve the electrochemical properties of NaxTMO2 cathodes for SIBs in the future and the combined utilizations of multiple characterization techniques. This review will provide significant guidelines for rational designs of high-performance NaxTMO2 cathodes.