JACS Au
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2023
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IF 8
Qi Yang,Xiujuan Gao,Faen Song,Xiaoxing Wang,Tao Zhang,Pan Xiong,Yunxing Bai,Xingchen Liu,Xiaoyan Liu,Junfeng Zhang,Gang Fu,Yisheng Tan,Yizhuo Han,Qingde Zhang
Selective oxidation of C–H bonds under mild conditions is one of the most important and challenging issues in utilization of energy-related molecules. Molybdenum oxide nanostructures containing Mo5+ species are effective for these reactions, but the accurate identification of the structure of active Mo5+ species and the catalytic mechanism remain unclear. Herein, unsaturated penta-coordinated Mo5c5+ with a high fraction in MoOx fabricated by the hydrothermal method were identified as the active sites for low-temperature oxidation of dimethyl ether (DME) by the deep correlation of characterizations, density functional theory calculations, and activity results, giving a methyl formate selectivity of 96.3% and DME conversion of 12.5% at unreported 110 °C. Low-temperature electron spin resonance (ESR) and quasi in situ X-ray photoelectron spectra (XPS) with the designed experiments confirm that the Mo5c5+ species can be formed in situ. Molybdenum located at the pentachronic site is preferable to significantly promote the oxidation of the C–H bond in CH3O* at lower temperatures.
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INTERNATIONAL JOURNAL OF PHARMACEUTICS
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2023
·
IF 5.8
Shuai Zhang,Quanzhi Zhang,Runmei Xu,Junyao Ma,Liang Fang
Transdermal drug delivery system (TDDS) was an effective way to realize controlled drug delivery. However, realizing zero-order controlled drug skin delivery was still challenging in the drug-in-adhesive patch. This study provided a strategy to accomplish this delivery form by stabilizing the drug concentration in adhesive through concentration-dependent competitive interaction. Clonidine (CLO) and Granisetron (GRA) were chosen as the model drugs which were of high skin permeability, and polydimethylaminoethyl acrylate (EA) as an excipient to interact with hydroxyphenyl adhesive (HP). Drug release, permeation and pharmacokinetic study were conducted to evaluate the controlled effect of HP-EA. The molecular interaction was characterized by FT-IR, 1 H NMR and XPS. Dynamic simulation and molecular docking further clarified the competitive interaction involved in the release process. Both the drug skin permeation study of CLO and GRA patch based on the HP-EA adhesive showed good zero-order fitting with r of 0.994 and 0.998, compared with non-functional adhesive (0-PSA). Furthermore, the pharmacokinetic study of the CLO patch showed a plateau phase for around 52 h without influencing the area under concentration–time curve ( AUC ), indicating that the HP-EA could realize zero-order drug skin delivery. The mechanism study revealed that EA serving as a ‘buffer component’ promoted the conversion of the ionic CLO to the neutrals the as the neutrals released, which stabilized ‘1% neutrals CLO concentration’. In conclusion, the drug delivery system based on the concentration-dependent competitive interaction broadened our understanding of the molecular mechanisms involved in zero-order controlled release in transdermal patches which would promote the development of zero-order drug delivery in TDDS.
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Nature Communications
·
2023
·Vol. 14
·期 1
·1-12
·
IF 16.6
Li Guowei,Jiang Shihui,Liu Aijun,Ye Lixiang,Ke Jianxi,Liu Caiping,Chen Lian,Liu Yongsheng,Hong Maochun
Crystal-field perturbation is theoretically the most direct and effective method of achieving highly efficient photoluminescence from trivalent lanthanide (Ln 3+ ) ions through breaking the parity-forbidden nature of their 4 f -transitions. However, exerting such crystal-field perturbation remains an arduous task even in well-developed Ln 3+ -doped luminescent nanocrystals (NCs). Herein, we report crystal-field perturbation through interstitial H + -doping in orthorhombic-phase NaMgF 3 :Ln 3+ NCs and achieve a three-orders-of-magnitude emission amplification without a distinct lattice distortion. Mechanistic studies reveal that the interstitial H + ions perturb the local charge density distribution, leading to anisotropic polarization of the F − ligand, which affects the highly symmetric Ln 3+ -substituted [MgF 6 ] 4− octahedral clusters. This effectively alleviates the parity-forbidden selective rule to enhance the 4 f –4 f radiative transition rate of the Ln 3+ emitter and is directly corroborated by the apparent shortening of the radiative recombination lifetime. The interstitially H + -doped NaMgF 3 :Yb/Er NCs are successfully used as bioimaging agents for real-time vascular imaging. These findings provide concrete evidence for crystal-field perturbation effects and promote the design of Ln 3+ -doped luminescent NCs with high brightness.
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ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Shuang Yang,Yinan Lao,Wenjin Yu,Zhenyu Tang,Haoqing Guo,Ganghong Liu,Bo Qu,Lixin Xiao,Zhijian Chen
Tin-based perovskites comprise one of the preferred nontoxic alternatives to Pb-based perovskites due to their desirable optoelectronic properties. However, there remains a crucial stability problem due to the property of Sn2+ oxidation. In this study, we reported stable tin-based perovskite nanocrystals (NCs) using stannous acetate as the Sn2+ source because of its stronger Sn–O bonding. To prevent the oxidation of Sn2+, a thin layer of CsBr coverage was formed in situ; tin-based perovskite NCs, CsxSnBrx+2@CsBr (1 < x < 4), show a high photoluminescence quantum yield (PLQY) of 78.2% and high stability. The measured lifetime of PLQY decrease to half of the initial value is ∼1287 h under ambient conditions and ∼2200 h under a nitrogen atmosphere, respectively. Furthermore, the as-fabricated light-emitting diodes based on CsxSnBrx+2@CsBr NCs as the emitting layer exhibit a maximum luminescence of 16 cd/m2 and an external quantum efficiency of 0.035% with peaks at 451 and 615 nm, corresponding to the emissions of CsBr and CsxSnBrx+2, respectively. This work provided a new way to obtain stable Sn-based perovskite NCs and exhibited their potential for application in white light-emitting diodes (LEDs).
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RADIATION RESEARCH
·
2023
·Vol. 200
·期 3
·242-255
·
IF 3.4
Abdous Slimane,Derradji Mehdi,Mekhalif Zineb,Khiari Karim,Mehelli Oussama,Cherif Younes Bourenane
Given their substantial neutron capture cross-section, extreme hardness, and high chemical and thermal stability, boron-based materials are widely used as building blocks to protect against highly ionizing radiations such as gamma rays and neutrons. Indeed, uncontrolled nuclear radiation exposure can be highly hazardous to radiation workers and the public. In this sense, this work presents an extensive study and experimental evaluation of the nuclear shielding features of hexagonal-boron nitride (h-BN) based nanocomposite, where bisphenol-A based polybenzoxazine (BA-PBz) was used as matrix. The neutron shielding studies were carried out at the nuclear research reactor of Algeria NUR. The surface treatment of h-BN nanoparticles was confirmed by FTIR and XPS techniques. The curing behavior and the degradation phenomena of the nanocomposites were evaluated by DSC-TGA analyses. The distribution of h-BN nanoparticles within the polymer matrix was assessed by TEM and SEM. The results showed that the developed boron nitride-based nanocomposite exhibits intriguing shielding performances and good thermal stability. The DSC-TGA tests exhibit high degradation temperature that reach 279°C. The highest performances were obtained at an h-BN concentration of 7 wt%, where the macroscopic cross was found to be (Σ = 3.844 cm –1 ) with a screening ratio of (S = 96.12%), equivalent to a mean free path (λ) of 0.138 cm.
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JOURNAL OF SOLID STATE CHEMISTRY
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2023
·
IF 3.3
Binbin Zhang,Huizhong Zhao,Yajie Gao,Qingge Wang,Zhihao Xi,Kui Wang
On the basis of the method used by Reinsch and Solovyeva, the aluminum based MOF material CAU-10-H (CAU stand for Christian-Albrechts-University) was synthesized by multiplying the amount of aluminum sulfate octahydrate and isophthalic acid by 10 times. CAU-10-H (b) is obtained after washing. In order to improve the water vapor adsorption performance of pure CAU-10-H (b), lithium chloride (LiCl) solution was compounded with CAU-10-H (b) by impregnation method to obtain a composite adsorbent CAU-10-H (L) and its adsorption characteristics were studied. The results showed that the composite adsorbent showed good adsorption and desorption performance under test conditions. Among them, the equilibrium adsorption capacity of the composite adsorbent with 33.1% LiCl content is 0.5007 g/g after 30 cycles, which is about 1.675 times of the adsorption capacity of pure CAU-10-H (b) under the same conditions. This shows the potential of the composite adsorbent to be used in the air-water extraction system.
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ANALYTICAL CHEMISTRY
·
2022
·
IF 8.008
Guojuan Zhang,Yujie Han,Zhiguang Liu,Lifang Fan,Yujing Guo
A triple-amplified and ratiometric electrochemical aptasensor for CA125 was designed based on hemin–graphene/SH-β-cyclodextrin@PdPt nanoflower (H-Gr/SH-β-CD@PdPtNF) composites and an exonuclease I (Exo I)-assisted strategy. In the nanocomposite, hemin acts as an internal reference signal owing to the reversible heminox/heminred pair. PdPtNFs can significantly improve the electron transfer rate. SH-β-CD can efficiently enrich quercetin probes through host–guest recognition and increase the second indicator signal. In the presence of CA125, due to the specific binding between the aptamer and CA125, the conformational change of dsDNA (designed by the CA125 aptamer and its complementary DNA) results in the release of quercetin embedded in dsDNA. Subsequently, the free quercetin and DNA fragments are enriched on the H-Gr/SH-β-CD@PdPtNF-modified electrode. Thus, an enhanced oxidation peak from quercetin (IQ) and a reduced peak from hemin (Ihemin) can indicate the same biological identification event. In addition, the recycling amplification of CA125 by Exo I can effectively assist the increase of the quercetin signal. The value of IQ/Ihemin is linear with the concentration of CA125 in the range from 6.0 × 10–4 to 1.0 × 103 ng/mL, and the limit of detection is 1.4 × 10–4 ng/mL. The recovery of CA125 in human blood serum samples was from 99.2 to 104.4%. The proposed sensor is sensitive and reliable, which provides an avenue for the development of triple amplification and ratiometric signal strategies for detecting tumor markers in clinical diagnostics.
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Energies
·
2019
·Vol. 12
·期 15
·2966
·
IF 2.707
Pijian Gong,Xinxue Li
In this study, NaClO2was selected as a denitration oxidant. In order to clarify the mechanism of NaClO2as an oxidation agent for NO removal efficiency, the effects of H+and other factors (NaClO2concentration, temperature, and the other gas) on the NO removal efficiency were investigated. NaClO2showed a promotional ability on NO removal, whose efficiency increased with the increase of NaClO2concentration. One hundred percent removal efficiency of NO could be achieved when the NaClO2concentration was 0.014 mol/L. Furthermore, raising the reaction temperature benefited the removal of NO. The lower the pH, the better the NO removal efficiency. The promoting effect of H+on the NO removal was studied by the Nernst equation, ionic polarization, and the generation of ClO2. Under the optimal conditions, the best removal efficiency of NO was 100%. Based on the experimental results, the reaction mechanism was finally speculated.Keywords:sodium chlorite (NaClO2);wet scrubbing;removal efficiency;NO reaction mechanism
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PROGRESS IN ORGANIC COATINGS
·
2019
·
IF 3.42
Bingjie Zou,Xijiang Chang,Jingxia Yang,Shuchuan Wang,Jingli Xu,Shirong Wang,Seiji Samukawa,Lidong Wang
h-BN nanoflakes were treated in three plasma gases (Ar、Ar+H 2 (4:1)、Ar + NH 3 (4:1)) for surface modification. The structure characterization (XRD, IR, XPS etc.) of h-BN indicated that the plasma treatment not only enlarged the interlayer distance of h-BN, but also increased the NH/OH surface groups and the ratio of exfoliated h-BN planes. The plasma treated h-BN exhibited better dispersion and stronger Fe 2+ holding ability in acrylic resin than the pristine h-BN, resulting in smaller corrosion current density (i corr ) and larger charge transfer resistance for the acrylic coating on low carbon steel, especially treated in Ar + NH 3 (4:1).
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Journal of Chemistry
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2019
·
IF 1.727
Song-qi Hu,Yin Wang,Lin-lin Liu
Hexagonal boron nitride (h-BN) powders were fabricated by the combustion synthesis with B/KNO3/HMX (octogen) mixtures as reactants. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were adopted to investigate the phase composition and the chemical composition of the products, respectively. The morphology and resistance to oxidation were studied by scanning electron microscopy (SEM) and thermogravimetry (TGA), respectively. The characterization results showed that the h-BN which was produced through this method has high purity and exhibits excellent resistance to oxidation. The purity of h-BN is improved with the increasing content of HMX in reactants with boron carbide (B4C) and boron oxide (B2O3) as main impurity, but conversely, the yields are obviously decreased. Taking the comprehensive consideration of the purity and the yields together, the optimal molar ratio of B/KNO3/HMX is 10 : 1 : 4. In addition, the experimental results indicated that the crystalline grain size grows with the increasing content of HMX. The method explored in this study does not need expensive processing facilities and equipment, which is a preferable approach for the laboratory to prepare h-BN of high purity.
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CATALYSIS LETTERS
·
2018
·Vol. 148
·期 11
·3492-3501
·
IF 2.911
Wang Xueyuan,Chen Li,Huang Deqi,Yue Jinfang,Luo Zhichen,Zeng Tao
Abstract The views on catalytic activity of zeolite in isomerization of α -pinene have not came to an agreement. Thus, the key active substance in zeolite was further studied through experiments. H-mordenite was treated in three ways: (i) calcination under nitrogen flows, (ii) calcination under oxygen flows, (iii) calcination under nitrogen flows after alkali treatment. The properties of modified zeolites were investigated by methods of SEM, EDS, XRD, nitrogen adsorption, NH 3 -TPD, Py-IR, and 29 Si and 27 Al MAS NMR. The results showed that the zeolites produced mesoporous after 0.4M NaOH solution soaking and calcinations above 500 °C, but it had a slight effect on the change of micropore volumes. Comparison of zeolite acid sites amount under different roasting temperature by NH 3 -TPD showed that the decrease of acid sites amount was mainly related to the roasting temperature. Py-IR and 27 Al MAS NMR experiment revealed that Lewis acid was produced by framework aluminum. Finally, Analysis on the influencing factors we studied of H-mordenite catalytic activity in this paper suggested that, in isomerization of α -pinene, the relative concentration of six-coordination aluminum in zeolite is the dominant factor of provided catalytic activity of H-mordenite. Graphical abstract
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JOURNAL OF HAZARDOUS MATERIALS
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2018
·
IF 6.434
Tian Liu,Jinming Luo,Xiaoyang Meng,Liming Yang,Bin Liang,Meijun Liu,Chengbin Liu,Aijie Wang,Xia Liu,Yong Pei,Jili Yuan,John Crittenden
Although noble metal electrocatalysts are highly efficient in the dehalogenation of halogenated antibiotics, the prohibitive cost hinders their practical applications. In this study, a cobalt-phosphorous/oxide (Co P/O) composite prepared via a one-step electrodeposition was for the first time applied in electroreductive dechlorination of halogenated antibiotics (HA), including chloramphenicol (CAP), florfenicol (FLO) and thiamphenicol (TAP). Co P/O had a higher FLO dechlorination efficiency (91%) than Pd/C (69.3%) (t = 60 min, C 0 = 20 mg L −1 , applied voltage of −1.2 V vs. saturated calomel electrode (SCE)). Furthermore, the dechlorination efficiencies of Co P/O for CAP and TAP reached to 98.7 and 74.2%, respectively. The electron spin resonance and in situ Raman characterizations confirmed that atomic H* was produced via the Co P and the formation of Co Cl bonds occurred on the Co O in Co P/O. The Co Cl bond formation could trap HA molecules onto Co P/O and weaken the C Cl bond strength. The synergistic effect of H* attack and Co Cl bond was responsible for the high dechlorination efficiency. This study offers new insights into the interface mechanism of electroreductive dehalogenation process, and shows a great potential for the remediation of halogenated antibiotics contaminated wastewater.
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