查找使用阿拉丁产品的科研文献

From Pb(H2C3N3O3)(OH) to Pb(H2C3N3O3)F: Homovalent Anion Substitution-Induced Band Gap Enlargement and Birefringence Enhancement

Yan Chen,Chunli Hu,Zhi Fang,Yilin Li,Jianggao Mao

Birefringent materials capable of modulating the polarization of light have attracted intensive studies because of their wide utilization in optical communication and the laser industry. Herein, two new lead(II)-based cyanurates, namely, Pb(H2C3N3O3)X (X = OH, F), were synthesized by hydrothermal methods, and the first halogen-containing metal cyanurate Pb(H2C3N3O3)F was successfully obtained by the rational substitution of a homovalent anion. Pb(H2C3N3O3)X (X = OH, F) belong to space group P1̅, and their structures display a neutral [Pb(H2C3N3O3)X] (X = OH, F) layer. The Pb2+ ions in Pb(H2C3N3O3)(OH) are interconnected by hydroxyl groups and oxygen atoms of cyanurate anions into a 1D [PbO(OH)]− chain, whereas the Pb2+ ions in Pb(H2C3N3O3)F are interconnected by F– anions and oxygen atoms of cyanurate anions into a 2D [PbOF]− layer. The π–π interactions between adjacent hydroisocyanurate rings and the hydrogen bonds between neighboring neutral layers provide additional stability to the structures. Luminescent studies show that Pb(H2C3N3O3)(OH) and Pb(H2C3N3O3)F emit yellow-green and blue light, respectively. Theoretical calculations unveiled their birefringences of 0.079 and 0.203@1064 nm and their band gaps of 3.96 and 4.96 eV, respectively, for OH– and F– containing materials. Obviously, the substitution of OH– by F– with the largest electronegativity can simultaneously improve both the birefringence and band gap.

Effects of Vitamin B12 on the Reductive Transformation of PFOS and F-53B by Nanoscale Zero-Valent Zinc

Perfluorooctane sulfonate (PFOS) and 6:2 chlorinated polyfluoroalkyl ether sulfonate (F-53B) are persistent per- and polyfluoroalkyl substances of concern in aquatic environments. This study compared their anaerobic reductive transformation by nanoscale zero-valent zinc (nZn0), with and without vitamin B12 (VB12). Solutions containing 1 mg/L PFOS or F-53B were treated with nZn0(278 mg/L) and, where indicated, 0.05 mmol/L VB12 (67.8 mg/L) at pH 8.5 and 30 °C for 20 days. After correction for losses observed in reagent-free blanks, PFOS loss was negligible with nZn0alone but reached approximately 34% with nZn0+ VB12, and the corresponding defluorination rate was 33.9%. In contrast, F-53B showed approximately 85% blank-corrected loss by day 6 with either nZn0alone or nZn0+ VB12, while defluorination rates reached 38.0% and 30.7%, respectively, indicating no enhancing benefit of VB12 for F-53B under the studied conditions. Nominal-mass LC-MS/MS features consistent with partially defluorinated and hydrogen-substituted products were observed, and tentative transformation pathways were proposed. These results demonstrated compound-specific effects of VB12 and emphasized the distinction among loss, transformation and defluorination when evaluating PFAS destruction.

Synthesis of robust superhydrophobic EP/F-CNTs/SiO2 composite coating with excellent anti-corrosion and wear-resistant property

Zhou Jie,Su Jingying,Su Fenghua,Zhao Tianxin,Li Ji,Yang Pengfei,Zhang Qingyu

At present, superhydrophobic coatings have a wide range of applications in self-cleaning, drag reduction, and corrosion protection. However, their poor mechanical stability has a significant impact on the service life and effectiveness of the coatings. In addressing this challenge, this study introduced epoxy resin (EP) with high strength and strong adhesion as the resin matrix. The composite coating, synthesized through a straightforward spraying technique, incorporates modified carbon nanotubes (F-CNTs) and hydrophobic fumed nanosilica (SiO 2 ) as fillers. The robust EP/F-CNTs/SiO 2 superhydrophobic coating exhibited excellent anti-rubbing ability and superadhesion strength, which was attributed to the EP intermediate layer significantly enhancing the adhesion strength between the coating and the stainless steel substrate with a remarkable adhesion grade of one. Tafel and EIS test results revealed a corrosion inhibition efficiency of up to 99.75% for the coating. The exceptional corrosion resistance of the coating is attributed to the outstanding electron transfer capability of F-CNTs. In addition, the coating could resist corrosion from strong acids and bases. It is believed that the facile and low-cost method offers an effective strategy and promising industrial applications for fabricating robust and super anti-corrosion superhydrophobic surfaces on various metallic materials.

TiH2 content-tuning strategy for synergistic enhancement of safety and combustion performance in HMX/TiH2/F composite microspheres

Penglin Kang,Jinbo Guo,Xiaojuan Fu,Yuan Lai,Xiangru Li,Leixin Hou,Wenjie Liu,Xiaodong Li

To achieve high-energy composites with both high energy density and enhanced safety, TiH 2 /HMX/F energetic microspheres were fabricated using a coaxial flow-focusing microdroplet technique. The effects of varying TiH 2 contents on the chemical structure, thermal decomposition, mechanical sensitivity, combustion characteristics, and combustion products were systematically examined. The results show that the microspheres exhibit a dense structure, narrow particle-size distribution, and uniform component dispersion, while retaining the crystalline form and chemical structure of the raw HMX and TiH 2 . With increasing TiH 2 content (5, 10, 15, and 20 wt%), the apparent activation energy rises by 21.58, 66.35, 98.33, and 146.09 kJ mol −1 , respectively, compared with the H/F sample, indicating reduced reactivity but significantly improved thermal stability. At 10 wt% TiH 2 , the critical impact energy and friction force increase by 4.0 J and 164.0 N, respectively, demonstrating enhanced mechanical safety. Combustion tests reveal that TiH 2 not only strengthens combustion intensity but also prolongs the reaction duration. When the TiH 2 content exceeds 5 wt%, oxidation becomes more complete, with TiO 2 and TiN identified as the main products. In addition, the combustion mechanism was clarified, highlighting the role of TiH 2 in promoting high-temperature oxidation and improving combustion completeness. These findings provide both theoretical insights and process guidance for optimizing the performance and safety of high-energy composite materials.

Synergistic Removal of Bromate and Ibuprofen by Graphene Oxide and TiO2 Heterostructure Doped with F: Performance and Mechanism

Yan Zhang,Jiarong Li,Hongyuan Liu

The batch experiments of photocatalytic oxidation-reduction of bromate and ibuprofen (IBP) by graphene oxide (GO) and TiO2 heterostructure doped with F (FGT) particles were conducted. The performance and mechanism of synergistic removal of bromate and IBP by FGT were discussed. The results show that a demonstrable synergistic effect and excellent removal rate of bromate and IBP by FGT were exhibited. When pH is 5.2 and the dosage of FGT is 0.1 g/L, the reaction rate constants of bromate and IBP increased from 0.0584 min-1 and 0.4188 min-1 to 0.1353 min-1 and 0.4504 min-1, respectively, compared with the degradation of bromate or IBP alone. The reaction of photocatalytic synergistic degradation is appropriately fitted through Langmuir-Hinshelwood first-order kinetics. The mechanism of synergistic removal of bromate and IBP by FGT was discussed. And electrons (e-), hydroxyl radical (⋅OH), and superoxide radical (⋅O2-) are the main active species. The electrons play a main role in the bromate reduction, and bromine is the only reduction product, while the oxidation of IBP is the result of ⋅OH and ⋅O2-, and ⋅OH plays a key role. The recombination of electrons and holes is inhibited by simultaneous consumption of bromate and IBP, which makes full use of the redox properties of FGT and plays a synergistic role in the removal of pollutants. The results indicate that photocatalytic oxidation-reduction by FGT is a promising, efficient, and environmental-friendly method for synchronous removal of combined pollution in water.

Interface-oriented engineering of bio-fermented bamboo-derived carbon via F/O doping for advanced sodium-ion storage

Dongke Cai,Mingxia Tang,Shuai Jiang,Debin Yan,Yinchuan Zhu,Yan Meng,Dan Xiao,Qian Zhao,Wei Feng,Xicui Zhang

This study presents a sustainable F/O co-doped hard carbon (PD-F800) derived from panda excrement via NH 4 F-assisted hydrothermal doping for sodium-ion battery anodes. PD-F800 delivers a reversible capacity of 472.87 ± 5.1 mAh g −1 at 100 mA g −1 with an initial Coulombic efficiency of 66.2 ± 2.1 %, maintains 317.72 ± 4.0 mAh g −1 at 1000 mA g −1 , and retains 72.7 ± 3.3 % capacity after 1000 cycles. In situ XRD/Raman, EIS/DRT and GITT jointly indicate that F/O co-doping introduces non-bonded F states and regulates defect/interfacial chemistry, which lowers Na + adsorption/desorption barriers, increases Na + diffusion kinetics, and stabilizes an inorganic-rich SEI, thereby coupling fast surface-controlled storage with reversible interlayer/pore processes. This work establishes a safe, scalable route from waste biomass to high-performance anodes and clarifies the structure-interface-kinetics linkage enabling advanced Na-ion storage.

Strategic Design of High-Capacity P2-Type Sodium Layered Oxides Enabled by Multifunctional Li/F/Cu Co-Doping

Yu Duan,Zihan Ma,Jiaxuan He,Yingying Huang,Shuo Bao,Jinlin Lu

P2-type layered cathode materials have low energy density due to low initial Na content. In this research, high sodium content P2-type cathode material Na0.8Li0.08Ni0.23Mn0.67Cu0.1O1.92F0.08 (NMC-LF), was synthesized by a simple high-temperature solid-phase method. The strong electronegativity of F allows the local TM-O bond to be transformed into a TM-F bond, and the TMO6 octahedron becomes more stable. The doping of Li+ not only maintains structural stability but also transforms the two-phase reaction in the high-voltage range into a solid-solution reaction. This leads to an effective suppression of the irreversible P2–O2 phase transition in the high-voltage region. At 20 mA·g–1, the initial discharge capacity of NMC-LF reaches 131.05 mAh·g–1. At a high current density of 200 mA·g–1, the discharge capacity reaches 101.9 mAh·g–1 and remains at 99.31% after 150 cycles. The diffusion coefficient of NMC-LF is as high as 8.67 × 10–13 cm2·s–1. Furthermore, the structural evolution during material formation is elaborated by high-temperature XRD, and it is determined that there are no impurities at 900 °C. Under the joint synergy of Li/F/Cu and the design of high sodium content, the long-cyclic and high-rate performance has been significantly improved. In-situ XRD tests show that Li/F/Cu codoping inhibits the P2–O2 phase transition and enhances structural reversibility. This provides a new idea for the research of layered cathode materials.

Activation or passivation: Influence of halogen dopant (F, Cl, Br) on photothermal activity of Mn2O3 in degrading toluene

Xiao Yu,Mengyi Shi,Yixuan Fan,Lixia Yang,Jie Zhang,Wei Liu,Weili Dai,Shuqu Zhang,Lei Zhou,Xubiao Luo,Shenglian Luo

Mn 2 O 3 is an exceptional earth-abundant mineral that has been extensively applied in catalytic oxidation because of the strong redox couples like Mn 3+ /Mn 2+ and Mn 4+ /Mn 3+ exposed on Mn 2 O 3 surface. Herein, the catalytic activity of Mn 2 O 3 in photothermal degradation of toluene was regulated by halogens including F - , Cl -, and Br - . As the electronegativity ordered in F (3.98) > O (3.44) > Cl (3.16) > Br (2.96), F - doped Mn 2 O 3 overperforms Cl - doped and Br - doped Mn 2 O 3 in decomposing toluene. DFT theoretical calculation illustrates that F - attracts the shared electrons from Mn to itself, the deviated charge center stretches the adjacent Mn-O bonds and boosts the generation of abundant oxygen vacancies, helping to strengthen the catalytic activity of Mn 2 O 3 . Conversely, Mn-O bonds are shortened by Cl - and Br - that have lower electronegativity than O. The multiple electrons circling Cl - and Br - push Mn towards O and squeeze Mn-O bonds, resulting in the formation of passivated Mn 2 O 3 . In conjunction with Mn redox couples and oxygen vacancies, 99% of 400 ppm toluene can be eliminated by F - doped Mn 2 O 3 , corresponding mineralization rate is high up to 95.8%.

Miniemulsion polymerization-formulated poly(fluorene-alt-6-(2-ethylhexyl)-[1,2,5]thiadiazole[3,4-f]benzotriazole) for cancer cell imaging

Zhiguo He,Xuejiao Han,Hui Xie,Zifeng Yan,Bing Guo,Youwei Yao

Near-infrared (NIR) conjugated polymer nanoparticles (CPNPs) possesses advantages for bioimaging because of their merits in low autofluorescence interference, good biocompatibility, large light extinction coefficient, improved photostability, and facile functionalization capability. Different from conventional post-polymerization methods for fabricating NIR CPNPs, like nanoprecipitation, emulsion and solvent evaporation/miniemulsion, and self-assembly, herein, an efficient one-pot strategy by in-situ miniemulsion polymerization is demonstrated to synthesize CPNPs for NIR fluorescence imaging of cancer cells. Via adjusting the donor-acceptor strength , the new CP, poly(fluorene- alt -6-(2-ethylhexyl)-[1,2,5]thiadiazole[3,4- f ]benzotriazole) ( PFTA ), show absorption and emission maximum at 648 nm and 730 nm, respectively, which is much more red-shifted than its counterpart, poly(fluorene- alt -benzo-2,1,3-thiadiazole) ( PFBT ). DFT calculation demonstrates that the repeating unit of PFTA has a smaller dihedral angel to 33.2° and much reduced energy gap to 2.46 eV, as compared to that of PFBT NPs. Importantly, through controlling surfactant concentrations from 40 g·L −1 to 2.5 g·L −1 during the miniemulsion polymerization, the particles size can be accordingly changed from even 88 to 210 nm. Furthermore, the particles show extinction coefficient of 2.82 × 10 4  M −1 ·cm −1 at 648 nm, photoluminescence quantum yields c.a. 2.4% and fluorescence lifetime c.a. 1.26 ns, respectively. Moreover, the PFTA NPs exhibit biocompatibility, good colloidal stability and bright fluorescence signals to clearly pinpoint breast cancer cells, with a trend that smaller NP size, higher cellular uptake. This work demonstrates the promise of miniemulsion polymerization as a facile method to fabricate NIR CPNPs for bioimaging.

Enabling Sensitive and Stable X-ray Detection in a 2D Trilayered Hybrid Perovskite with Strong F–π Interactions

Peixuan Zhu,Huawei Yang,Lemei Long,Panpan Yu,Chengmin Ji,Zeng-Kui Zhu,Ying Zeng,Shihai You,Junhua Luo

Organic–inorganic hybrid perovskites integrate the advantages of organic and inorganic components, making them promising candidates for high-performance X-ray detection. However, severe ion migration under external voltage makes it a tough challenge to realize high sensitivity and operational stability simultaneously in practical application. Here, we report a two-dimensional (2D) trilayered hybrid perovskite with F-substituted aromatic spacers, (FBZA)2(MA)2Pb3Br10 (1, FBZA = 4-fluorobenzylamine, MA = methylamine). The thick inorganic slabs endow 1 with efficient carrier transport paths, achieving a superior mobility-lifetime product of 1.3 × 10–3 cm2 V–1, much higher than most of 2D perovskites. Indeed, a high sensitivity of 2818.2 μC Gy-1 cm–2 and a low detection of limit (LOD) of 43.7 nGy s–1, as well as a low dark current drift of 1.61 × 10–7 nA cm–1 s–1 V–1 under a bias of 100 V, suggests its great potential on sensitive and stable X-ray detection. The stable and reliable response to long-time X-ray irradiation of high dose rate under large working voltage further verifies its operational stability. This research develops a multilayered 2D perovskite with strong interlayer interactions, successfully achieving high-sensitivity and high-stability X-ray detection, which sheds light on the design and construction of high-performance perovskite-based X-ray detectors in the future.

A Large Family of Centrosymmetric and Chiral f-Element-Bearing Iodate Selenates Exhibiting Coordination Number and Dimensional Reductions

Meiying Qie,Jian Lin,Fang Kong,Mark A. Silver,Zenghui Yue,Xiaomei Wang,Linjuan Zhang,Hongliang Bao,Thomas E. Albrecht-Schmitt,Jian-Qiang Wang

The exploration of phase formation in the f-element-bearing iodate selenate system has resulted in 14 novel rare-earth-containing iodate selenates, Ln(IO3)(SeO4) (Ln = La, Ce, Pr, Nd; LnISeO-1), Ln(IO3)(SeO4)(H2O) (Ln = Sm, Eu; LnISeO-2), and Ln(IO3)(SeO4)(H2O)2·H2O (Ln = Gd, Dy, Ho, Er, Tm, Yb, Lu, Y; LnISeO-3), as well as two new thorium iodate selenates, Th(OH)(IO3)(SeO4)(H2O) (ThISeO-1) and Th(IO3)2(SeO4) (ThISeO-2). LnISeO-3 and ThISeO-2 crystallize in the chiral space group P212121, while LnISeO-1, LnISeO-2, and ThISeO-1 crystallize in the centrosymmetric space group P21/c. The numbers of both coordinating and hydrating water molecules crystallized in LnISeO-1, LnISeO-2, and LnISeO-3 increase along these three series, in line with the increasingly negative values of hydration enthalpies of heavier trivalent lanthanide ions. Such a systematic change in compositions, especially the first coordination sphere of Ln, further induces structural rearrangements, including coordination number and dimensional reductions. More specifically, the structures of LnISeO-1, LnISeO-2, and LnISeO-3 have undergone transitions from 2D Ln–oxo layers with 10-coordinate Ln centers to 1D Ln–oxo chains with 9-coordinate Ln centers and then to 0D Ln–oxo monomers with 8-coordinate Ln centers, respectively. The formation and characterization of this large family of Ln/Th iodate selenates suggest that such a mixed-anion system not only exhibits richer structural chemistry but also can be capable of generating intriguing properties, such as the second-harmonic generation (SHG) effect.

Fluorine-Doped Nb2O5 with Rich Oxygen Vacancies Anchored on the N/F Carbon Skeleton for Superior Lithium Storage

Yuda Lin,Yiheng Chen,Ye Fan,Shenghui Zheng,Liting Qiu

With the aim of improving the intrinsic conductivity of Nb2O5, we synthesized fluorine-doped Nb2O5 with rich oxygen vacancies anchored on the N/F carbon skeleton (F–Nb2O5@NFC) by a one-step annealing method. In this structure, F-doping greatly improves the intrinsic conductivity of Nb2O5, and the theoretical calculation results show that F–Nb2O5 has surprisingly zero band gap metal characteristics. At the same time, due to F-doping, a large number of oxygen vacancies are introduced into the structure, which increases the concentration of free electrons and further enhances the conductivity of the composites. In addition, the N/F codoped carbon skeleton ensures the rapid transmission of electrons. Under the blessing of multilevel conduction, F–Nb2O5@NFC exhibits excellent electrochemical performance, with a reversible specific capacity of 130 mAh g–1 after 1400 cycles at a current density of 3 A g–1, and the rate capacity reaches 110 mAh g–1 at a high current density of 10 A g–1.