Latest ArticlesIn 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).
Lithium-ion batteries (LiBs) with high energy density have gained significant popularity in smart grids and portable electronics. LiMn1-xFexPO4 (LMFP) is considered a leading candidate for the cathode, with the potential to combine the low cost of LiFePO4 (LFP) with the high theoretical energy density of LiMnPO4 (LMP). However, quantitative investigation of the intricate coupling between the Fe/Mn ratio and the resulting energy density is challenging due to the parametric complexity. It is crucial to develop a universal approach for the rapid construction of multi-parameter mapping. In this work, we propose an active learning-guided high-throughput workflow for quantitatively predicting the Fe/Mn ratio and the energy density mapping of LMFP. An optimal composition (LiMn0.66Fe0.34PO4) was effectively screened from 81 cathode materials via only 5 samples. Model-guided electrochemical analysis revealed a nonlinear relationship between the Fe/Mn ratio and electrochemical properties, including ion mobility and impedance, elucidating the quantitative chemical composition-energy density map of LMFP. The results demonstrated the efficacy of the method in high-throughput screening of LiBs cathode materials.
Herein, an alkyne-terminated acid/base responsive amphiphilic [2]rotaxane shuttle was synthesized, and then modified onto the glass surface through "click" reaction. The XPS N 1s spectrum and contact-angle measurement were performed to prove the successful immobilization. The amphiphilic [2]rotaxane functionalized surface presented controllable wettability responding to external acid-base stimuli. This bistable rotaxane modified material system promoted the practical application of molecular machines.
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.
Herein, 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.
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.
Excessive Fe3+ ion concentrations in wastewater pose a long-standing threat to human health. Achieving low-cost, high-efficiency quantification of Fe3+ ion concentration in unknown solutions can guide environmental management decisions and optimize water treatment processes. In this study, by leveraging the rapid, real-time detection capabilities of nanopores and the specific chemical binding affinity of tannic acid to Fe3+, a linear relationship between the ion current and Fe3+ ion concentration was established. Utilizing this linear relationship, quantification of Fe3+ ion concentration in unknown solutions was achieved. Furthermore, ethylenediaminetetraacetic acid disodium salt was employed to displace Fe3+ from the nanopores, allowing them to be restored to their initial conditions and reused for Fe3+ ion quantification. The reusable bioinspired nanopores remain functional over 330 days of storage. This recycling capability and the long-term stability of the nanopores contribute to a significant reduction in costs. This study provides a strategy for the quantification of unknown Fe3+ concentration using nanopores, with potential applications in environmental assessment, health monitoring, and so forth.
Optimizing the interfacial quality of halide perovskites heterojunction to promote the photogenerated charge separation is of great significance in photocatalytic reactions. However, the delicately regulation of interfacial structure and properties of halide perovskites hybrid is still a big challenge owing to the growth uncontrollability and incompatibility between different constituents. Here we use BiOBr nanosheets as the start-template to in situ epitaxially grow Cs3Bi2Br9 nanosheets by “cosharing” Bi and Br atoms strategy for designing a 2D/2D Cs3Bi2Br9/BiOBr heterojunction. Systematic studies show that the epitaxial heterojunction can optimize the synergistic effect of BiOBr and Cs3Bi2Br9 via the formation of tight-contact interfaces, strong interfacial electronic coupling and charge redistribution, which can not only drive the Z-scheme charge transfer mechanism to greatly promote the spatial separation of electron-hole pairs, but also modulate the interfacial electronic structure to facilitate the adsorption and activation of toluene molecules. The heterojunction exhibited 62.3 and 2.4-fold photoactivity improvement for toluene oxidation to benzaldehyde than parental BiOBr and Cs3Bi2Br9, respectively. This study not only proposed a novel dual atom-bridge protocol to engineer high-quality perovskite heterojunctions, but also uncovered the potential of heterojunction in promoting electron-hole separation as well as the application in photocatalytic organic synthesis.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
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
