查找使用阿拉丁产品的科研文献

Sensitive fluorescence sensor for isoliquiritigenin determination based on N-doped carbon dots

Yi Zhang,Ziyi Zhao,Hui Wu

Fluorescence nanosensor based on carbon dots (CDs) is an up-and-coming platform for precise determination of isoliquiritigenin (ISO), ensuring human health and environmental safety. Herein, biomass nitrogen-doped carbon dots (BN-CDs) were assembled through a one-pot hydrothermal platform with lemon peel and melamine as precursors, which could be developed as distinguished sensors to detect ISO. The structure and optical properties of BN-CDs were explored in detail through some analytical methods. The BN-CDs indicated excellent UV resistance performance and biocompatibility. Moreover, after the addition of ISO, the blue fluorescence could be significantly quenched, and an eminent linear relationship was acquired between ln(F 0 /F) and ISO concentrations. The fitting equation was ln(F 0 /F) = 0.054[ISO] + 0.0085 (R 2  = 0.9978) with the concentration range of 0–50 μM. 0.056 μM of detection limit was obtained based on the 3b/k. This nanosensor was successfully carried out in real samples with satisfactory recoveries of 93.3–103.9 %. This research offered a theoretical foundation towards ISO determination via blue-emitting CDs and indicated huge application potential.

Distinction of n-alkanols in biodiesel fuel by diffusion-ordered NMR spectroscopy

Guo Wenying,Huang Guilan,Yuan Ling,Zhang Wenxin,Xia Mingzhu

Recently, higher alkanols have attracted the attention of researchers because, compared with other widely studied lower alkanols (such as ethanol and methanol), they have higher energy density, higher cetane number, better mixing stability and lower hygroscopicity. In biodiesel, alkanols are often added to improve the combustion performance of diesel engines. The qualitative of alkanol components is particularly important for the quality control of biodiesel. A reliable analysis method is demanded to distinguish the various alkanols in biodiesel. This study employed diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY NMR) to establish a quantitative relationship model between diffusion coefficients and molecular weights of n-alkanols in DMSO‑ d 6 . It is found that the deviation from theoretical molecular weight (ΔMW) of the external calibration curves (ECCs) using dimethyl sulfoxide (DMSO) (0.46–1.88) as internal standards can significantly reduce the MW error than the internal calibration curves (ICCs) (1.05–2.65). The calibration curve of ECCs shows excellent fitting degree (R 2  = 0.999) and effectively mitigates the impact of external variables: ΔMW remains within ±7 when the concentration ranges from 0.05 to 100 mg/mL or the temperature varies from 288 K to 308 K. Based on the molecular weight determined by this method, n-alkanols that differ by only one carbon atom could be distinguished accurately, and the method has been validated in actual biodiesel samples containing C 4 -C 8 n-alkanols.

Photocatalytic degradation of n-propanol wastewater by TiO2 combined with Fenton reactions

Huiming Zeng,Liang Lv,Rui Fan,Yulin Wang,Xiaoli Shen,Jianjun Chen,Jianguang Li

Photocatalytic degradation by ultraviolet (UV)/TiO 2 combined with Fenton reagent was employed in treating high concentration n-propanol solution. The influence of the TiO 2 dosage, the concentration of ferrous ion, the integral H 2 O 2 dosage and the optimizing H 2 O 2 adding program were investigated by a series of batch experiments. The increasing injection of the hydrogen peroxide during the reaction will make the reaction rate constant (k 1 ) 6.9% higher than the average injection when the integral H 2 O 2 dosage is fixed. The optimized parameters of the combined process can be listed as follow: [Fe 2+ ] was 0.30 g/L, [TiO 2 ] was 0.08 g/L, and average [H 2 O 2 ]b was 3.85 g/L (which was divided into six different parts, and the increasing gradient was 5%). After 6 h degradation under the ultraviolet (UV) photocatalytic irradiation, more than 88% removal of n-propanol was observed. When the wastewater is treated with the combined process, the degradation of n-propanol can be taken as the pseudo-first order reaction. Based on the experimental data, a semi-empirical model for estimating the reaction rate constant k 1 in cylindrical reactor was built, which will help to investigate the effect of system parameters and support further engineering design.

N–O Codoped Carbon Nanofibers Decorated with Graphene for High-Performance Supercapacitors

Xin Hou,Penggang Ren,Zhong Dai,Zhengzheng Guo,Zengping Zhang,Aiyue Sun,Wenwei He,Fang Ren,Yanling Jin

Herein, nitrogen, oxygen codoped porous carbon nanofibers (CNFs) from corn residue-derived lignin are fabricated via the electrospinning method, followed by introduction of graphenes (GNs) via a simple “brush-coating and drying” process. The obtained GN-coated carbon nanofibers (CNFs@GNs) exhibit a 3D network architecture, abundance of heteroatoms, excellent electrical conductivity, high specific surface area (700.92 m 2 g −1 ), thus boosting the electrochemical performances. The CNFs@GNs electrode delivers a higher specific capacitance of 271.1 F g −1 than CNFs (200.3 F g −1 ) at 1 A g −1 . Furthermore, the assembled CNFs@GNs symmetric supercapacitor exhibits an energy density of 20.3 Wh kg −1 at the power density of 199.97 W kg −1 together with a high charge/discharge reversibility of 97.3% and Coulombic efficiency of 99.81% after 10 000 cycles. This “brush-coating and drying” strategy utilized here provides a convenient and efficient route for designing CNFs and GN composites and can be utilized in other active materials.

Infrared Spectroscopic Insight into Hydration Behavior of Poly(N-vinylcaprolactam) in Water

Shengtong Sun,Peiyi Wu

IR spectroscopy in combination with two-dimensional correlation spectroscopy (2DCOS) and the perturbation correlation moving window (PCMW) technique is employed to illustrate the dynamic hydration behavior of poly(N-vinylcaprolactam) (PVCL) in water, which exhibits a typical type I continuous lower critical solution temperature (LCST) behavior. PCMW easily determined the transition temperature to be ca. 43.5 °C during heating and ca. 42.5 °C during cooling and the transition temperature range to be 39.5–45 °C. On the other hand, 2DCOS was used to discern the sequence order of different species in PVCL and concluded that hydrogen bonding transformation predominates at the first stage below LCST while hydrophobic interaction predominates at the second stage above LCST. In combination with molecular dynamics simulation results, we find that there exists a distribution gradient of water molecules in PVCL mesoglobules ranging from a hydrophobic core to a hydrophilic surface. Due to the absence of self-associated hydrogen bonds and topological constraints, PVCL mesoglobules would form a “sponge-like” structure which can further continuously expel water molecules upon increasing temperature, while poly(N-isopropylacrylamide) (PNIPAM) with self-associated hydrogen bonds forms mesoglobules with a “cotton-ball-like” structure without an apparent distribution gradient of water molecules and does not change much upon increasing temperature.

N-Acetylcysteine Attacks Phenoloxidase to Inhibit Insect Melanization and Boost Fungal Virulence

The prophenoloxidase (PPO) melanization cascade is a cornerstone of insect humoral immunity against fungal pathogens, yet its direct fungicidal mechanism remains undefined, and strategies to safely manipulate this pathway for biological control are lacking. Here, we demonstrate that infection ofDrosophilaby the entomopathogenic fungusBeauveria bassianaelicits a surge in phenoloxidase (PO) activity directly triggered by the fungal cell wall component β-1,3-Glucan. This activated PO generates reactive oxygen species (ROS) that are essential for restricting fungal proliferation, thereby establishing a mechanistic link between cascade activation and fungicidal outcome. Critically, we uncover that N-acetylcysteine (NAC), a safe, low-cost pharmaceutical in global clinical use, acts as a potent direct inhibitor of PO enzymatic activity, neutralizing the melanization-driven ROS burst. NAC-mediated inhibition significantly acceleratesB. bassianavirulence and host mortalityin vivo. Our work defines a new molecular function for NAC as a melanization inhibitor and reveals a safe, translatable strategy to suppress host immune defenses, offering a promising approach to enhance the efficacy of fungal biopesticides for sustainable pest control worldwide.

An Efficient NTAamide(n-Oct) Extraction Resin for High-Purity Thorium Preparation

Zhuang Wang,Dongping Su,Ting Luo,Qiao Yu,Yiting Wang,Hang Zhou,Rui Li,Qing-Jiang Pan,Songdong Ding

High-purity thorium is essential for producing key radioactive nuclides, such as 233U and 225Ac. Currently, the primary challenge in preparing high-purity thorium is separating trace amounts of uranium and rare earth impurities from crude thorium products. To address this, an efficient NTAamide(n-Oct)@CG71M extraction resin was developed for isolating high-purity thorium in a nitric acid medium containing uranium and rare earth elements. Batch adsorption studies exhibit high selectivity and strong adsorbability for thorium over a relatively wide acidity range of 0.10–8.0 mol/L HNO3. The adsorption of thorium onto the resin conforms to pseudo-second-order kinetics and the Langmuir model, with a maximum Th(IV) adsorption capacity (qmax) of 79.9 mg/g. Thermodynamically, the process is exothermic and spontaneous, accompanied by an increase in the entropy. The NTAamide(n-Oct) extractant in the resin coordinates with Th(IV) via three oxygen atoms of the carbonyl groups and one tertiary amine nitrogen atom. Dynamic separation experiments confirmed that the NTAamide(n-Oct)@CG71M extraction resin can efficiently remove trace uranium impurities from commercial thorium nitrate reagents, yielding high-purity thorium nitrate (99.99%). Furthermore, the resin selectively separated thorium from simulated monazite HNO3 leach liquor with a 99.4% recovery rate and high-purity thorium (99.99%) while demonstrating good reusability. Overall, this efficient extraction resin provides reliable technical support for high-purity thorium nitrate preparation and shows significant application potential.

Controlled synthesis of N–CuCo2S4@Ni3S2 nanoarrays as promising urea oxidation electrocatalyst

Na Wu,Xiaoqiang Du

One of the most attractive means for mitigation of environmental pollution is to produce hydrogen by electrocatalytic urea splitting. In the paper, the heterogeneous interfacial rich N–CuCo 2 S 4 @Ni 3 S 2 material was in situ synthesized on nickel foam through a typical hydrothermal and sulfuration process. This N–CuCo 2 S 4 @Ni 3 S 2 electrode displays excellent urea oxidation performance (potential of 1.38 V@50 mA cm −2 ), which is one of the best reactivity reported so far. Experimental results show that the superior catalytic activity is attributed to the rapid charge transfer, more reaction center exposed and superior electrical conductivity . Density functional theory shows that this Ni 3 S 2 material accelerates the reaction rate in the catalytic process, the introduction of this N–CuCo 2 S 4 material improves the conductivity of the material, and the synergistic catalysis of the N–CuCo 2 S 4 and Ni 3 S 2 makes this N–CuCo 2 S 4 @Ni 3 S 2 material exhibit superior urea oxidation activity. Notably, long-term tests have shown a decrease in catalytic activity, which suggests that the surface of the sulfide is in situ generated to oxides or hydroxides, which are truly active species. This work provides a new idea for the development of efficient and stable urea oxidation catalysts for sulfides.

Isomerization pathway of N-ethylcarbazole hydrogenation products affected by metal-support interactions

Bin Wang,Shu-han Lu,Shi-yuan Wang,Pei-ya Li,Tao Fang

N -ethylcarbazole (NEC) is a widely studied liquid organic hydrogen carrier, and a large number of catalysts with excellent reactivity has been designed and developed thus far. However, the phenomenon of isomeric transformation of 12H-NEC products during the reaction was not explained. Here, we studied the process based on three different Ru catalysts supported on zirconium-based supports, and based on the experimental results, we identified that supported metal-support strong interaction (SMSI), metal-support anion interaction (MSAI) and hydrogen spillover will have coupling effect on the hydrogenation reaction path and the occurrence of isomerization in 12H-NEC product. Higher 12 [H] B content in 12H-NEC under Ru/ZrN catalyst was caused by the large number of secondary active centers on the surface of the support reacting in the hydrogenation reaction. The active site for the isomerization of 12 [H] B to 12 [H] A may be the electronegativity interface formed by Ru and the support, while the electroneutral or electropositive interface rich in hydrogen is not conducive to the catalytic conversion. To sum up, an image model for the isomeric transformation of 12H-NEC products was proposed.

N-doped C-coated MoO2/ZnIn2S4 heterojunction for efficient photocatalytic hydrogen production

Dong Wei,Zhou Shi-An,Ma Yan,Chi Dian-Jun,Chen Rong,Long Hong-Ming,Chun Tie-Jun,Liu Sheng-Jun,Qian Fu-Ping,Zhang Kui

Designing a heterojunction photocatalyst to improve the separation efficiency of photogenerated electrons and holes is of great significance to improve the hydrogen production efficiency. In this work, we report a rational design to grow ZnIn 2 S 4 on Mo-MOF-derived N-doped C-coated MoO 2 (MOZIS), and it has excellent photocatalytic hydrogen production with triethanolamine (TEOA) as sacrificial agent. N-doped C improves the electron transport efficiency between MoO 2 and ZnIn 2 S 4 . The systematic study shows that MOZIS has good properties to promote the effective separation and transfer of photocatalytic charges, which is attributed to the tight contact interface and good energy band structure between MoO 2 and ZnIn 2 S 4 . The optimized nanocomposites have a high hydrogen production efficiency of 10.89 mmol·g −1 (4 h) under visible light. MOF-derived N-doped C-coated MoO 2 is an effective strategy to improve the photocatalytic hydrogen production efficiency of ZnIn 2 S 4 . Graphical abstract

Preparation of N-Doped Layered Porous Carbon and Its Capacitive Deionization Performance

Rui Liu,Shouguang Yao,Yan Shen,Yu Tian,Qiqi Zhang

In this study, N-doped layered porous carbon prepared by the high-temperature solid-state method is used as electrode material. Nano calcium carbonate (CaCO3) (40 nm diameter) is used as the hard template, sucrose (C12H22O11) as the carbon source, and melamine (C3H6N6) as the nitrogen source. The materials prepared at 850 °C, 750 °C, and 650 °C are compared with YP-50F commercial super-activated carbon from Japan Kuraray Company. The electrode material at 850 °C pyrolysis temperature has a higher specific surface area and more pores suitable for ion adsorption. Due to these advantages, the salt adsorption capacity (SAC) of the N-doped layered porous carbon at 850 °C reached 12.56 mg/g at 1.2 V applied DC voltage, 500 mg/L initial solution concentration, and 15 mL/min inlet solution flow rate, which is better than the commercial super activated carbon as a comparison. In addition, it will be demonstrated that the N-doped layered porous carbon at 850 °C has a high salt adsorption capacity CDI performance than YP-50F by studying parameters with different applied voltages and flow rates as well as solution concentrations.Keywords:capacitive deionization;N-doped layered porous carbon;salt adsorption capacity

N-Doped Carbon/CeO2 Composite as a Biomimetic Catalyst for Antibacterial Application

Nan Wang,Xiaofan Zhai,Fang Guan,Ruiyong Zhang,Baorong Hou,Jizhou Duan

Exploring new and high efficiency mimic enzymes is a vital and novel strategy for antibacterial application. Haloperoxidase-like enzymes have attracted wide attention thanks to their amazing catalytic property for hypohalous acid generation from hydrogen peroxide and halides. However, few materials have displayed halogenating catalytic performance until now. Herein, we synthesized N-doped C/CeO2(N-C/CeO2) composite materials by a combination of the liquid and solid-state method. N-C/CeO2can possess haloperoxidase-like catalytic activity by catalyzing the bromination of organic signaling compounds (phenol red) with H2O2at a wide range of temperatures (20 °C to 55 °C), with a solution color changing from yellow to blue. Meanwhile, it exhibits high catalytic stability/recyclability in the catalytic reaction. The synthesized N-C/CeO2composite can effectively catalyze the oxidation of Br−with H2O2to produce HBrO without the presence of phenol red. The produced HBrO can resist typical marine bacteria likePseudomonas aeruginosa. This study provides an efficient biomimetic haloperoxidase and a novel sustainable method for antibacterial application.Keywords:N-C/CeO2composite;catalytic materials;biomimetic catalyst;haloperoxidase-like enzyme;antibacterial