查找使用阿拉丁产品的科研文献

One stone, several birds: A carboxyl-carbazole-rich fluorescent covalent organic framework for the detection of tetrabromobisphenol S, Fe³ ⁺, ascorbic acid, D/L-arginine, and the removal of tetrabromobisphenol S

Jiaqi Hu,Mingyue Wang,Min Wang,Dandan Wang,Yuqiang Xiao,Yue Lan,Lingling Li,Meiling Yang,Minmin Wang,Leijiao Peng,Famin Ke,Xiurong Guo,Die Gao

Considering the efficient utilization of resources and the simultaneous detection of multiple analytes, achieving selective detection of diverse analytes on one fluorescent covalent organic framework (COF) is of great significance. Herein, a carboxyl-carbazole-rich fluorescent COF (COF-DABT) was strategically synthesized using 3,6-diamino carbazole, capable of forming halogen bonds with analytes, and 2,5-bis(4′-formylphenyl) terephthalic acid, rich in carboxyl groups, which interacts with various analytes and adjusts fluorescence performance via its electron-withdrawing properties. The introduction of carbazole imparts fluorescence to COF-DABT through the intramolecular charge transfer (ICT) effect, while enabling selective fluorescence quenching. Specifically, the ICT of carbazole can be disrupted via linear halogen bond interactions with TBBPS, resulting in selectively detection of TBBPS in a fluorescence-off mode. Furthermore, efficient enrichment of TBBPS is facilitated by halogen bonds with carbazole and hydrogen bonds with carboxyl groups on COF-DABT. Selective fluorescence quenching of COF-DABT by Fe 3 + is achieved through chelating effect around carboxyl group, as well as cation-π interaction with carbazole benzene ring. This enables high selectivity detection of Fe 3+ via a fluorescence-off mode. Additionally, Fe 3+ can be reduced by ascorbic acid through REDOX reaction, mitigating interference with TBBPS detection and facilitating fluorescence-off-on mode detection of AA. Besides, rich carboxyl groups on COF-DABT exert a negative regulatory effect on the carbazole ICT mechanism. To counter this, D/L-Arg, with a size complementary to the adjacent carboxyl groups on COF-DABT, is introduced. Hydrogen bond interactions between D/L-Arg and carboxyl groups reduce the negative regulatory effect, allowing fluorescence enhancement for highly selective detection of D/L-Arg. Through rational design and functional optimization of fluorescent COF structures, multi-mode detection methods enable simultaneous detection of different analytes, achieving the goal of "one stone, several birds."

0D-2D Interaction: Pt quantum dots trigger the strain effect of S-NiFeP nanosheet to achieve ampere-level current density overall water splitting performance of Pt@S-NiFeP/NF electrode

Xiao Chen,Yating Hou,Jinghan Xu,Ningyuan Song,Xinru Wei,Yanru Liu,Kang Liu,Yunmei Du,Lei Wang

Nowadays, the electrocatalytic regulation mechanism of quantum dots (QDs)-supported materials is limited to strong metal-support interaction (SMSI) and electron-metal-support interaction (EMSI). However, the lattice strain of the carrier induced by QDs is neglected, which is not conducive to the directional design of the QDs-supported electrode and the establishment of its structure-performance correlation. Given these, the size and distribution of Pt QDs controlled by electrodeposition effectively regulate the strain degree on S-NiFeP nanosheets. DFT results reveal that Pt@S-NiFeP/NF complies with a Fe-Pt dual active sites mechanism for alkaline HER, and a Fe active site mechanism for OER. Interestingly, the compressive strain in the S-NiFeP substrate effectively promotes the d‐band center shift and the energy barrier reduction, thereby optimizing the alkaline HER and OER kinetics. As expected, Pt@S-NiFeP/NF with appropriate strain owns alkaline HER and OER performance at 1 A cm −2 that exceeds the commercial Pt/C and RuO 2 . Overall, this work has guided the structural design of the 'noble metal QDs@carrier' model and laid a foundation for its application at ampere-level current densities.

Highly selective and sensitive detection of trace amoxicillin with a novel fluorescent nanoprobe N, S-CDs@MIP based on S/N co-doped carbon quantum dots combined with molecularly imprinted polymer

Leikai Ye,Fangyan Chen,Yubin Tang,Wenqian Sun,Yanhua Song

At present, the rapid, sensitive, and highly selective detection of trace organic contaminants is a research spot in the field of environment. Herein, a novel fluorescent nanoprobe N, S-CDs@MIP based on N/S co-doped carbon quantum dots (CDs) coupled with amoxicillin molecularly imprinted polymer was synthesized. The fluorescent property of N, S-CDs@MIP and fluorescence quenching level of amoxicillin to N, S-CDs@MIP was explored. Furthermore, the fluorescence analysis method based on N, S-CDs@MIP probe for quantitatively detecting amoxicillin was established. The synthesized N, S-CDs@MIP has a maximum fluorescence emission wavelength of 440 nm and a significantly selective fluorescence response toward amoxicillin with a large imprinting factor of 4.07. For the developed fluorescence analysis method, the detection limit, the linear range of the standard curve, and relative standard deviation (RSD) were obtained as 1.17 ng/mL, 5.8–200 ng/mL, and <3 %, respectively. The real environmental water samples were measured with a high accuracy with the recovery of 83.6 % ~ 104.7 % and RSD of 2.3 % ~ 5.1 %. Compared to the HPLC-UV, HPLC-MS, and the fluorescence detection method based on CDs or doped CDs, the established fluorescence detection method exhibits high selectivity, wide linear range, and low detection limit. It is greatly promising in the quick detection of trace amoxicillin.

A hierarchical carbon fiber/sulfur composite as cathode material for Li–S batteries

Feng Wu,Lili Shi,Daobin Mu,Hongliang Xu,Borong Wu

A novel hierarchical structure carbon/sulfur composite is presented based on carbon fiber matrices, which are synthesized by electrospinning. The fibers are constituted with hollow graphitized carbon spheres formed using catalytic Ni nano-particles as hard templates. Sulfur is loaded to the carbon substrates via thermal vaporization. The structure and composition of the hierarchical carbon fiber/S composite are characterized with X-ray diffraction, scanning electron microscopy, transmission electron microscopy , Raman spectroscopy , and nitrogen adsorption isotherms . The electrochemical performance is evaluated by cyclic voltammetry and galvanostatic charge–discharge. The results exhibit an initial discharge capacity of 845   mA   h   g −1 at 0.25   C (420   mA   g −1 ), with a retention of 77% after 100 cycles. A discharge capacity of 533   mA   h   g −1 is still attainable when the rate is up to 1.0   C. The good cycling performance and rate capability are contributed to the uniform dispersion of sulfur, the conductive network of carbon fibers and hollow graphitized carbon spheres.

Polypyrrole-Reinforced N,S-Doping Graphene Foam for Efficient Solar Purification of Wastewater

Lifen Su,Yuying Ning,Ziqiang Ma,Yuhao Zhang,Chuanlei Liu,Youli Zhang,Lei Miao,Jianhua Zhou,Bin Wu,Jiasheng Qian

Solar vapor generation is a sustainable and cost-effective approach to addressing the issue of water shortage. However, the challenges of solar steam generation still exist for achieving a high evaporation efficiency combined with long-term stability in the wastewater containing heavy metal ions and wide degrees of acidity and alkalinity (pH = 1–14). Herein, polypyrrole (PPy) loading on the N,S-doped graphene oxide (N,S-GO) foam is used for high-efficiency solar evaporation of treating wastewater. With the advantages of excellent broadband solar absorption ( >97%), extremely low emissivity (0.70), and outstanding hydrophilicity, the N,S-GO/PPy foam achieves a high evaporation efficiency of 90.5% under 1 sun illumination. More notably, the N,S-GO/PPy foam has strong adsorption of heavy metal ions (Fe 3+ , Cu 2+ , and Cr 6+ ) for treating wastewater synchronously evaporates at higher efficiencies of 94.7–98.4%. Interestingly, the high-toxicity Cr 6+ can be reduced to low-toxicity Cr 3+ effectively by the synergistic effect of N,S-GO and PPy. In addition, the N,S-GO foam shows a better long-term resistance of acidity and alkalinity for 45 days. A new insight is offered into high-efficiency solar evaporation for treating wastewater and water purification.

Aggregation-induced Emission-active Hyperbranched Poly(tetrahydropyrimidine) s Synthesized from Multicomponent Tandem Polymerization

Huang Yuzhang,Chen Ping,Wei Bo,Hu Rongrong,Tang Ben Zhong

Hyperbranched polymer with highly branched three-dimensional topological structure, a large number of end groups, and multifaceted functionalities have gained much attention, while polymers with aggregation-induced emission (AIE) properties become a group of popular luminescent materials recently. The design and synthesis of AIE-active hyperbranched polymers, which combine the advantages of these two types of materials, are attractive but challenging. In this work, four hyperbranched poly(tetrahydropyrimidine)s were synthesized from the metal-free room temperature multicomponent tandem polymerization of diester group-activated internal alkyne, polyfunctional aromatic amines, and formaldehyde in methanol under the catalysis of acetic acid. Through different monomer combination and controlling the monomer loading order, hyperbranched polymers with various topological structures as well as sequences of different functional groups in the polymer backbone were obtained with high molecular weights (up to 3.0 × 10 4 g/mol) in high yields (up to 98%). The hyperbranched poly(tetrahydropyrimidine) emitted faintly in solution, while its luminescence was notably enhanced in the aggregated state, suggesting its typical aggregation-induced emission property. It is anticipated that the multicomponent polymerization may provide a synthetic platform for the construction of hyperbranched polyheterocycles with diverse structures and functionalities.

Activating NiO via Fe doping for ultrafast polysulfide conversion in Li-S batteries

Chenglin Wei,Mengdi Sun,Baoguo Zhang,Zhangyong Yan,Zihao Dang,Yongkang Xu,Lin Wu,Ya Hu

Benefiting from the low cost and natural abundance of sulfur, as well as its excellent theoretical performance metrics - including a capacity of 1675 mAh g −1 and an energy density of 2600 Wh kg −1 - lithium-sulfur (Li-S) batteries have attracted considerable attention for next-generation energy storage. However, their practical deployment is severely hindered by the intrinsic shuttle effect of lithium polysulfides (LiPSs), which leads to the loss of active materials and poor cycling stability. In this work, we report a facile hydrothermal-calcination strategy to synthesize porous nanosheet-structured Fe-doped nickel oxide (Fe-NiO) as a functional separator modifier for Li-S batteries. The polar nature of NiO enables strong chemical interactions with LiPSs, effectively anchoring polysulfides on the cathode side and suppressing the shuttle effect. Furthermore, Fe doping significantly increases the density of surface active sites, thereby enhancing the adsorption and catalytic conversion of LiPSs into insoluble Li 2 S 2 /Li 2 S species, which promotes redox kinetics and mitigates capacity fading. When applied to Li-S cells, the Fe-NiO-modified separator markedly improves the electrochemical performance, delivering a high reversible capacity of 1150 mAh g −1 at 0.2C, an excellent rate capability of 505 mAh g −1 at 5C, and outstanding long-term stability with a minimal capacity decay of 0.091 % per cycle over 500 cycles at 1C. This study presents a simple and scalable strategy for separator engineering, providing a promising pathway toward high-performance Li-S batteries.

Stabilizing superionic Ag2S1-xTex phase to room temperature via S/Te size disparity

Yuxin Shao,Chengwei Gao,Yanqing Fu,Shiliang Kang,Linling Tan,Baoan Song,Shixun Dai,Changgui Lin

Superionic β -Ag 2 S demonstrates exceptional ionic conductivity and ductility, rendering highly promising for applications in electrochemical sensors, thermoelectric devices and solid-state electrolytes. However, it is still haunted by the limited thermodynamic stability, transitioning to the poorly conductive α -Ag 2 S phase upon cooling to room temperature (RT). Herein, a solid solution formed by partial isovalent substitution of sulfur with tellurium stabilizes the superionic phase via the substantial atomic-size mismatch between S and Te. Specifically, Ag 2 S 1-x Te x (0.2 ≤ x ≤ 0.8) maintain superionic phase at RT without observable phase transition upon cooling. This stabilized superionic phase originates from the substantial size mismatched between S and Te. Furthermore, the anion disorder caused by the local volume expansion introduced by large-radius Te reduces the activation energy the activation energy barrier and provides more vacancies for Ag + ion transportation. This work confirms the efficiency of crystal amorphization strategy for stabilizing high-temperature superionic phases at ambient conditions, enabling the development of superionic conductors.

Fiber SPR Sensor Based on S-Taper Sensitivity Enhancement for Nickel Ion Detection

Yong Wei,Jing Cheng,Yabin Shao,Chunlan Liu,Puxi Ren,Yixiong Tang,Ziqiang Zhang,Mingjun Cai,Zhihai Liu

Limited Fraction of Crystallized Side Chains in Bottlebrush Poly(n-alkyl methacrylate)s

Xiang Ming-Yue,Lyu Dong,Liu Ling-Zhi,Men Yong-Feng

Crystallinity of bottlebrush polymers due to side chain crystallization has been considered to be related to the length of the side chains only under the assumption of complete participation of crystallization by all side chains. Recent experimental results revealed that in poly( n -alkyl methacrylate)s a fraction of side chains could not crystallize due to constraints imposed by the trapped main chain entanglements and required expansion of main chain-main chain distance. This result renders the original simplified consideration of the origin of crystallinity in bottlebrush polymers questionable. In this work, we introduce a new parameter f c , the fraction of crystallizable side chains, to better describe the crystallinity of bottlebrush polymers. A linear relationship between the melting enthalpy and the number of alkyl groups in side chains for bottlebrush polymers reported repeatedly indicates that f c remains essentially unchanged when bottlebrush polymers had the same main chain structure and grafting degree but different side chain lengths. The slope of the above-mentioned linear relationship is thus \(\Delta H_{\text{CH}_2}\times f_{c}\) , where \(\Delta H_{\text{CH}_2}\) stands for the melting enthalpy of one mole alkyl group packed into the crystal. With a known value of f c , it is possible to estimate the value of \(\Delta H_{\text{CH}_2}\) . In case of poly( n -alkyl methacrylate)s, we estimated \(\Delta H_{\text{CH}_2}\) of hexagonal crystal being at most 5.74 kJ/mol with the knowledge of possibly smallest f c of 0.67 obtained from small angle X-ray scattering data. Therefore, the crystallinity of bottlebrush polymer would be calculated based on the equation \(X_{\rm{c}}=f_{\rm{c}}\times\frac{N_{\rm{c}}}{N}\) with N and N c being the number of alkyl groups in a side chain and those packed in the crystalline structure, respectively. Both chemical structure and grafting degree of bottlebrush polymers affect f c .

Nacrelike Nanocomposite Films from Fluorescent Hyperbranched Poly(amido amine)s and Clay Nanosheets

Wentao Hao,Songyan Ding,Liang Zhang,Wei Liu,Wen Yang

Graphical Mother-of-pearl films : Flexible, transparent, and glossy nanocomposite films have been fabricated through vacuum-aided filtration self-assembly of hyperbranched poly(amido amine)s (HPAMAMs) and clay nanosheets. Such hybrid films show strong fluorescence properties and high strength (see figure). As a result of the good biocompatibility of HPAMAMs, the hybrid films are promising in biomedical research. Inspired by the hierarchical structure of nacre, lots of functional nanocomposite films have been fabricated through finely tuning the composition and structure. To broaden their application in biological and biomedical research, it is highly demanded to develop a new strategy to fabricate nanocomposite films that are both biocompatible and functional. Herein, hyperbranched poly(amido amine)s (HPAMAMs) have been assembled with clay nanosheets. The obtained nanocomposite films show good mechanical performance and fluorescence properties. Analysis of the structure of the nanocomposite films indicates that the HPAMAMs and the clay nanosheets are stacked together in an orderly manner. The clay nanosheets align in the direction parallel to the film surface. Because of the inherent biocompatibility and autofluorescence property of the HPAMAMs, such composite films are thought to be very promising in applications requiring biocompatibility, fluorescence, and good mechanical performance. The method should provide a new route to the fabrication of functional nacrelike composite materials.

Synthesis of alternating semi-aromatic poly(ester amide)s and the amide transesterification

He Tingwei,Liu Tao,Huang Junyao,Wang Xueli,He Yong,Ma Bomou

In this work, a novel poly(ester amide)s (PEAs) was designed and synthesized from dimethyl terephthalate (DMT), 3-amino-1-propanol (AP) and adipic acid (AA). Firstly, the aromatic diol monomer (BHTT) was synthesized by DMT and AP, it was characterized by 1 H NMR, 13 C NMR, FT-IR and DSC, respectively. Then, the BHTT and AA were used to synthesize the semi-aromatic PEAs with alternating structure by melt polymerization. The effects of polymerization temperature and time on the crystallization, thermal stability and amide transesterification of PEAs were fully investigated. It was found that the prepared PEAs are semi-crystalline polymer with melting point around 154–165 °C and decomposition temperature around 377–392 °C. Most important, the chemical structure of PEAs synthesized under different conditions was explored by 1 H NMR, 13 C NMR and DEPT spectra, which confirms the occurrence of amide transesterification during the melt polymerization process.