SEPARATION AND PURIFICATION TECHNOLOGY
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2024
·
IF 8.1
Hao Jiang,Mei Yan,Hao Chen,Xue Chen,Yutuo Fu,Chongshen Guo
How to make full use of solar energy and improve the efficiency of charges separation of photocatalysis has been a concern for scientists all along. To achieve this, this work designed an n-n + homojunction of S-doped SnFe 2 O 4 and applied it to near infrared driven photocatalytic degradation and sterilization. The experimental results demonstrated that S doping significantly enhanced the photocatalytic performance of SnFe 2 O 4 . The degradation rate of ciprofloxacin and the removal rate of Staphylococcus aureus ( S. aureus ) reached up to approximately 65 % and 100 % after 6 h irradiation, respectively. The S-doping could increase the content of shallow trap states in SnFe 2 O 4 , effectively inhibiting the recombination of photogenerated electrons and holes. Moreover, S-doping also enhances the n-type character and forms n-n + homojunction. This n-n + homojunction generates a built-in electric field within the sample, which causes band bending and promotes photogenerated charges transfer and separation. Consequently, more carries are available for the generation of reactive oxygen species. Free radical quenching experiments and ESR tests show that •O 2 − is the main free radical in the photocatalysis. In addition, DFT calculations confirmed the enhanced activation of O 2 after S doping. This work provides a feasible way to effectively promote charges separation and transfer in metalloid-based photocatalysts.
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ELECTROCHIMICA ACTA
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2011
·
IF 3.65
Yan Liang,Hongyun Liu,Kaina Zhang,Naifei Hu
N,N-diethylacrylamide (DEA) and 4-vinylpyridine (4VP) were polymerized into P(DEA-co-4VP) copolymer hydrogel films with immobilized glucose oxidase (GOD) on electrode surface with the simple one-step procedure under mild conditions, designed as P(DEA-co-4VP)-GOD. Cyclic voltammetric (CV) response of ferrocenedicarboxylic acid (Fc(COOH) 2 ) probe at P(DEA-co-4VP)-GOD film electrodes was very sensitive to environmental pH, temperature, and sulfate concentration. For example, in pH 5.0 buffers, the CV response of Fc(COOH) 2 was quasi-reversible with quite large peak heights at 25 °C for the films, showing the on state; while at pH 9.0, the peaks were greatly suppressed and the system was at the off state. This pH-sensitive on-off switching behavior of the films toward the probe was reversible and could be repeated for many times between pH 5.0 and 9.0. Similarly, the film system could be switched on-off reversibly when the temperature was changed between 25 and 39 °C, or when the concentration of Na 2 SO 4 was changed between 0 and 0.50 M. This triply responsive property could be further used to realize triply switchable electrochemical oxidation of glucose catalyzed by GOD immobilized in the films and mediated by Fc(COOH) 2 in solution. The responsive mechanism of the system was also explored and discussed. The pH-sensitive property was attributed to the electrostatic interaction between the P4VP component of the films and the probe at different pH, while the thermo- and sulfate-sensitive behavior was ascribed to the structure change of PDEA constituent of the films with temperature and Na 2 SO 4 concentration, respectively. These “smart” films combine the unique stimuli-responsive properties of both P4VP and PDEA with enzymatic reactions and may be used to fabricate a novel type of multi-controllable electrochemical biosensors based on bioelectrocatalysis.
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Soft Matter
·
2024
·Vol. 20
·期 37
·7448-7456
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IF 2.9
Cuihong Ma,Cong Du,Qing Bo Tong,Xin Ning Zhang,Miao Du,Qiang Zheng,Zi Liang Wu
Incorporating associative interactions as the energy dissipation units has been recognized as an effective strategy to develop tough hydrogels. For hydrogen-bond associations, however, it is highly challenging to stabilize them under aqueous conditions. Although affording cooperativity can enhance and stabilize the hydrogen bonds, it usually requires stepwise polymerization to form these cooperative associations between different polymers and networks. Here, we report a series of tough supramolecular hydrogels with robust hydrogen-bond associations between grafted polymers that are synthesized by polymerization of a macromonomer of poly(N,N-dimethylacrylamide) (PDMAA) and a small monomer of methacrylic acid. The grafted chains of PDMAA form cooperative hydrogen bonds with the main chain of poly(methacrylic acid) (PMAAc), forming supramolecular hydrogels with high toughness and good stability. The tough and stiff hydrogels are in a glassy state, exhibit forced elastic deformation at room temperature, and remain stable over a wide pH range. In contrast, hydrogels prepared by the copolymerization of DMAA and MAAc are swollen and weak in water due to the lack of successive hydrogen donor/acceptor units and the absence of cooperative hydrogen bonds. In addition, these tough hydrogels exhibit good recyclability and shape memory properties, owing to the supramolecular nature of the network and the temperature-dependent mechanical properties. The influence of polymer structure on the associative interactions and macroscopic properties of the hydrogels should be informative for the design of tough soft materials with versatile applications.
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PubMed
高影响因子
Journal of Energy Chemistry
·
2024
·
IF 14
Yutong Jing,Qiang Lv,Yujia Chen,Bo Wang,Bochen Wu,Cheng Li,Shengbo Yang,Zhipeng He,Dianlong Wang,Huakun Liu,Shixue Dou
Polymer solid electrolytes (SPEs) based on the [solvate-Li + ] complex structure have promising prospects in lithium metal batteries (LMBs) due to their unique ion transport mechanism. However, the solvation structure may compromise the mechanical performance and safety, hindering practical application of SPEs. In this work, a composite solid electrolyte (CSE) is designed through the organic-inorganic synergistic interaction among N , N -dimethylformamide (DMF), polycarbonate (PC), and Mg 2 B 2 O 5 in poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). Flame-retardant Mg 2 B 2 O 5 nanowires provide non-flammability to the prepared CSEs, and the addition of PC improves the dispersion of Mg 2 B 2 O 5 nanowires. Simultaneously, the organic-inorganic synergistic action of PC plasticizer and Mg 2 B 2 O 5 nanowires promotes the dissociation degree of LiTFSI and reduces the crystallinity of PVDF-HFP, enabling rapid Li ion transport. Additionally, Raman spectroscopy and DFT calculations confirm the coordination between Mg atoms in Mg 2 B 2 O 5 and N atoms in DMF, which exhibits Lewis base-like behavior attacking adjacent C–F and C–H bonds in PVDF-HFP while inducing dehydrofluorination of PVDF-HFP. Based on the synergistic coupling of Mg 2 B 2 O 5 , PC, and DMF in the PVDF-HFP matrix, the prepared CSE exhibits superior ion conductivity (9.78×10 −4 S cm −1 ). The assembled Li symmetric cells cycle stably for 3900 h at a current density of 0.1 mA cm −2 without short circuit. The LFP||Li cells assembled with PDL-Mg 2 B 2 O 5 /PC CSEs show excellent rate capability and cycling performance, with a capacity retention of 83.3% after 1000 cycles at 0.5 C. This work provides a novel approach for the practical application of organic-inorganic synergistic CSEs in LMBs.
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JOURNAL OF MOLECULAR STRUCTURE
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2024
·
IF 4
Tianyang Hou,Yuangang Xu,Ze Xu,Xiaopeng Zhang,Ming Lu
The formation of non-metallic pentazolate salts from the combination of simple nitrogen-rich cations with cyclo -N 5 − is expected to be applied in propellants and explosives. In this work, a series of structurally similar cations ([NH 3 CH 3 ] + , [NH 2 (CH 3 ) 2 ] + , [NH(CH 3 ) 3 ] + , and [N(CH 3 ) 4 ] + ) were used to synthesize four cyclo -N 5 − containing energetic salts, and the contribution of crystal stacking mode, hydrogen bonding, C–H··· π and π -stacking interactions in the stabilization of cyclo -N 5 − salts has been investigated by geometrical and Hirshfeld surface analyses as well as theoretical calculations. All salts have been thoroughly characterized by single-crystal X-ray diffraction, infrared (IR), multinuclear NMR ( 1 H and 13 C) spectroscopy, and elemental analysis. The decomposition temperatures of all salts are higher than 75 °C, as measured by thermogravimetric (TG). These compounds all show low sensitivities (IS ≥ 35 J, FS > 360 N) measured by standard BAM methods. Their heats of formation and detonation performances were calculated using the Born–Haber energy cycle and K-J method (“Pilem” program), respectively. This study has great significance for future design and synthesis of cyclo -N 5 − containing energetic materials.
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ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Long Li,Yan Wu
This study reports a strategy for constructing highly efficient single-atom photocatalysts through the formation of Ni–N chemical bonds. By anchoring Ni single atoms on nitrogen-doped ZnIn2S4 (N-ZIS), we created a localized charge region that enables directed interfacial charge transfer. The newly formed Ni–N bond plays dual roles of significantly enhancing charge carrier separation and prolonging their lifetime, and serving as an efficient electron transfer pathway from N trap states to Ni active sites. Combined experimental characterization and density functional theory (DFT) calculations confirm the unique stabilizing effect of single Ni atoms in the N-ZIS matrix and elucidate the charge transfer mechanism through Ni–N bridges. The optimized 5%Ni–N30-ZIS photocatalyst exhibits exceptional hydrogen evolution performance, surpassing most previously reported ZIS-based systems. This work highlights the crucial importance of precise control over interfacial chemical bonding at the molecular level for achieving efficient spatial charge separation in inorganic photocatalysts, providing insights for the design of high-performance photocatalytic materials.
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PubMed
高影响因子
Systems Microbiology and Biomanufacturing
·
2022
·Vol. 2
·期 3
·507-522
·
IF 0
Du Juanjuan,Zhang Liang
N -methyl- d -aspartic acid (NMDA), an amino acid existing in human and animal central nervous system, exerts agonist action on one of the glutamate receptor subtypes and is clinically used for treatment of diabetes, Parkinson’s and Alzheimer’s syndrome. In this study, an enzymatic protocol for the chiral resolution of N -methyl- d , l -aspartic acid was built with a predicted N -demethylase (GenBank ID: OJV90073.1) from the genome of Chloroflexi bacterium 54-19. Through sequence alignment, the enzyme shares an identity of 32.19% to 2UZZ (PDB ID) with a conserved catalytic center. Recombinantly expressed in Bacillus subtilis WB600 , the N -demethylase was characterized with optimal temperature and pH at 55 ℃ and 7.5, and adaptive temperature and pH were 40–60 ℃ and 6–8. The effects of organic solvents and metal ions were investigated as well. Compared with other previously reported sarcosine oxidases, the enzyme showed a specific N -demethylation activity against N -methyl- l -aspartic acid according to the analysis by chiral liquid chromatography, LC–MS/MS and a detection by polarimeter. The results demonstrated 76% of 4.5 mM N -methyl- d , l -aspartic acid could be chirally separated by 7 mg·L −1 enzyme after reaction of 80 min. This work provided a foundation for mild synthesis of NMDA in industry. Graphical abstract
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JOURNAL OF THE ELECTROCHEMICAL SOCIETY
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2013
·Vol. 160
·期 11
·H787
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IF 2.588
Mi Ouyang,Zhiyan Fu,Xiaojing Lv,Bin Hu,Pingjing Wang,Senbiao Huang,Yuyu Dai,Cheng Zhang
Copolymer based on 4-(9H-carbazol-9-yl)-N,N-diphenylaniline (CDPN) and 3,4-ethylenedioxythiophene (EDOT) was electrochemically synthesized and characterized. Through electrochemical methods, FTIR spectroscopy and scanning electron microscopy (SEM) analysis, the resulting polymer was confirmed to be a copolymer rather than a blend or a composite of the respective homopolymers. Besides, the spectroelectrochemical and electrochromic properties of the copolymer (P(CDPN-co-EDOT)) films were investigated. According to the spectroelectrochemical analysis, the copolymer film revealed distinct electrochromic properties with four colors: claret red, green, cadetblue, and blue. At the neutral state of the copolymer, the π-π* transition absorption peak was located at 530 nm and the energy gap was calculated as 1.67 eV. The copolymer film showed a maximum optical contrast (ΔT%) of 36% in visible region with a switching time of 1.8 s and 43% in the near-IR region with a switching time of 2.5 s. The coloration efficiency (CE) of P(CDPN-co-EDOT) were calculated to be 332 cm2·C−1 (at 530 nm), 277 cm2·C−1 (at 810 nm) and 552 cm2·C−1 (at 1100 nm). Repeated cyclic voltammograms indicated that the copolymer had reasonable stability because of the existence of EDOT units.
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Polymer Chemistry
·
2018
·Vol. 9
·期 13
·1674-1683
·
IF 4.927
Liguo Xu,Fan Zhou,Min Liao,Rongrong Hu,Ben Zhong Tang
The development of a new polymerization methodology affords polymer materials with new structures and functionalities. Multicomponent polymerizations (MCPs) as a facile tool for preparing multifunctional polymers with complicated structures have attracted increasing attention from polymer scientists, owing to their high efficiency, high atom economy, simple procedure, structural diversity, and environmental benefit. In this work, a series of efficient one-pot multicomponent polymerizations of diynes, disulfonyl azides, and N-protected isatins are developed to afford oxindole-containing poly(N-acylsulfonamide)s with advanced properties. After optimization of the polymerization conditions, the MCP can proceed smoothly at room temperature or 30 °C in dichloromethane/t-BuOH with CuI as the catalyst and LiOH as the base, generating poly(N-acylsulfonamide)s with high molecular weights of up to 30 600 g mol−1 in excellent yields of up to 98%. This MCP enjoys general applicability of a series of electron-rich or electron-deficient alkynes and alkyl group or aromatic group-substituted isatins, generating six poly(N-acylsulfonamide)s from different combination of monomers, and nitrogen gas as the only byproduct, demonstrating high atom economy and environmental benefit. The obtained poly(N-acylsulfonamide)s can be dissolved in alcohol or alcohol/water mixtures, but cannot be dissolved in THF or dichloromethane, which show opposite solubility after the polymers are acidified with HCl, indicating reversibly tunable hydrophilicity of the polymers. Furthermore, water can participate in the MCP as the fourth component when the MCP is conducted in DMF with CuI as the catalyst and Na2CO3 as the base, generating random copolymers consisting of 3-alkenyloxindole moieties and two chiral center-containing 3-hydroxyindole moieties in the backbone. Some of the oxindole-containing poly(N-acylsulfonamide)s exhibit yellow to red emission in their solid state. These MCPs provide an efficient approach for the synthesis of functional polymers with unique structures, which directly build the oxindole and N-acylsulfonamide moieties in situ, demonstrating high synthetic efficiency.
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高影响因子
CRYSTENGCOMM
·
2018
·Vol. 20
·期 8
·1151-1157
·
IF 3.304
Qiangwen Fan,Xiaowei Duan,Hong Yan
The solid state [2 + 2] photocycloaddition of N,N′-diacyl-1,4-dihydropyrazines has been investigated using thiourea as a template to preorient the reactants in the crystalline state in a manner that is beneficial for the [2 + 2] photocycloaddition. The structures of the photoadducts, syn-dimers and cage-dimers, were determined using NMR and single-crystal X-ray diffraction. According to the topochemical principles used to assess the feasibility of solid state photochemical [2 + 2] cycloaddition, topological analysis of cocrystals consisting of the N,N′-diacyl-1,4-dihydropyrazines and thiourea, as well as the syn-dimers, was performed to investigate the influence of packing modes and non-covalent interactions on their solid state photoreactivity. The results showed that the solid state [2 + 2] reactivities of both the N,N′-diacyl-1,4-dihydropyrazines assembled using thiourea and the syn-dimers were controlled by the topochemical orientation of the potentially reactive double bonds and the H-bonding interactions within the adjacent reactive molecules.
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高影响因子
ACS Applied Materials & Interfaces
·
2016
·
IF 7.145
Meilin Lv,Gang Liu,Xiaoxiang Xu
Strong visible light absorption and high charge mobility are desirable properties for an efficient photocatalyst, yet they are hard to be realized simultaneously in a single semiconductor compound. In this work, we demonstrate that these properties coexist in homologous compounds ZnnIn2O3+n (n = 4, 5, and 7) with a peculiar layered structure that combines optical active segment and electrical conductive segment together. Their enhanced visible light absorption originates from tetrahedrally or trigonal-bipyramidally coordinated In atoms in Zn(In)O4(5) layers which enable p–d hybridization between In 4d and O 2p orbitals so that valence band minimum (VBM) is uplifted with a reduced band gap. Theoretical calculations reveal their anisotropic features in charge transport and functionality of different constituent segments, i.e., Zn(In)O4(5) layers and InO6 layers as being for charge generation and charge collection, respectively. Efficient photocatalytic hydrogen evolution was observed in these compounds under full range (λ ≥ 250 nm) and visible light irradiation (λ ≥ 420 nm). High apparent quantum efficiency ∼2.79% was achieved for Zn4In2O7 under full range irradiation, which is almost 5-fold higher than their parent oxides ZnO and In2O3. Such superior photocatalytic activities of these homologous compounds can be understood as layer-by-layer packing of charge generation/collection functional groups that ensures efficient photocatalytic reactions.
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Desalination and Water Treatment
·
2024
·
IF 1
Yunfan Lu,Ruibin Wang,Guoping Wang,Nian Chen
To achieve rapid detection for metronidazole (MNZ), a mesoporous nickel-based metal–organic framework (Ni-MOF), which had sub-micron-assemblies of layered flakes and abundant carboxyl groups, was synthesized in a particular solvent containing water with a facile one-step hydrothermal method. Using Ni-MOF/multi-walled carbon nanotubes as the sensor electrode, cyclic voltammetry and differential pulse voltammetry were investigated in MNZ solution (containing 0.1 M PBS). The current response linearly varied with MNZ’s concentration in the range of 5–100 μM. A relatively low detection limit of 25 nM was obtained, which outperformed many electrochemical platforms for MNZ reported in literatures. Moreover, further investigations indicated this system was endowed with good anti-interference ability repeatability, and long-term stability. The present work was promising to pave the way for the quantitation of MNZ in biomedical and healthcare applications.
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