ChemistrySelect
·
2025
·Vol. 10
·期 35
·e03319
·
IF 2
Simombela Mikunga,Chanez Maouche,Peter Phiri,Shuang Wang,Chao Cheng,Juan Yang
The development of cost-effective, high-performance oxygen reduction reaction (ORR) electrocatalysts is pivotal for advancing energy conversion technologies such as metal–air batteries and fuel cells. Herein, we report a facile and efficient strategy to synthesize Mn nanoparticles loaded on N-doped hierarchically porous carbon framework (Mn/N-C) through utilizing ZIF-8 as a carbon/nitrogen precursor and MnCl 2 ·4H 2 O as the Mn source. The synthesis integrates mechanical grinding with an NaCl-assisted pyrolysis process, where molten NaCl acts as a dynamic template and intercalation agent to prevent structural collapse during carbonization, thereby creating a 3D porous architecture with coexisting micro-, meso-, and macropores. Physicochemical characterization reveals that the Mn/N-C-2 sample exhibits a high specific surface area (1770 m 2 /g), abundant defects, and uniform dispersion of Mn nanoparticles within the N-doped carbon matrix. Electrochemical evaluations demonstrate that Mn/N-C-2 catalyst possesses a higher half-wave potential ( E 1/2 ) of 0.836 V and a larger limiting current density ( J L ) of 5.54 mA/cm 2 , surpassing other control samples and most reported Mn-based catalysts and comparable to that of commercial Pt/C. When integrated into Zn–air batteries (ZABs), Mn/N-C-2-based ZABs deliver an open-circuit voltage of 1.49 V and a peak power density of 150.51 mW/cm 2 , outperforming benchmark Pt/C-based counterparts. This work offers a cost-effective electrocatalyst for ORR and can be used instead of noble metals in ZABs. Graphical Mn/N-C electrocatalysts are fabricated by a NaCl-assisted pyrolysis strategy. The optimized Mn/N-C-2 catalyst exhibits a large specific surface area, hierarchically porous architecture and high content of active N, presenting an E 1/2 of 0.836 V for ORR. When integrated into ZABs, it delivers an open-circuit voltage of 1.49 V and a peak power density of 150.5 mW/cm 2 .
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DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2018
·
IF 8.173
Xue Hu,Xidong Liu,Xiaodan Zhang,Hongxiang Chai,Yuming Huang
The fluorescent CuNCs/ZIF-8 nanocomposites were facilely prepared by mixing the PEI protected CuNCs with the precursors of ZIF-8, and characterized by UV–vis absorption, fluorescence, FT-IR, TEM , XRD and XPS . The quantum yield of the CuNCs/ZIF-8 is 15 times that of the PEI-CuNCs. Furthermore, the CuNCs/ZIF-8 possesses better stability and higher fluorescence response due to protective and confinement effects of MOFs . It was found that H 2 O 2 could cause much more quenching of fluorescent CuNCs/ZIF-8 than that of PEI-CuNCs, which might result from enriching H 2 O 2 by ZIF-8. The CuNCs/ZIF-8 can be designed as a fluorescence probe to selectively and sensitively detect H 2 O 2 with a linear range from 0.01 to 1.5 µM and a LOD of 0.01 µM, while those with PEI-CuNCs are 0.5–30 µM and 0.50 µM, respectively. Through formation of CuNCs/ZIF-8 hybrid, the sensitivity for the detection of H 2 O 2 increases by nearly 50-fold, which makes CuNCs/ZIF-8 a desirable probe to detect H 2 O 2 content in human serum samples. Also, we successfully demonstrated the potential application of the CuNCs/ZIF-8 for screening and evaluating activities of oxidase using glucose oxidase as a model. The glucose oxidase activity can be detected in a range of 0.1–10 mU/L with a LOD of 0.1 mU/L.
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PubMed
高影响因子
Polymers
·
2022
·Vol. 14
·期 24
·5466
·
IF 4.967
Changcai Teng,Xiongyan Meng,Yeqin Hu,Hongzhao Mao,Huiting Li,Jing Yang,Tiantian Sun,Shuai Meng,Chengli Zong
Small synthetic TLR7/8-agonists can be used as vaccine adjuvants to enhance cell and humoral-mediated immune responses to specific antigens. Despite their potency, after local injection they can be dispersed to undesired body parts causing high reactogenicity, limiting their clinical applications. Here we describe a vaccination strategy that employs the covalent conjugate of a mannose and TLR7/8 agonist as a vaccine adjuvant to take advantage of mannose binding C-type lectins on dendritic cells to enhance the vaccine’s immunogenicity. The mannose-TLR7/8 agonist conjugate can self-assemble into nanoparticles with the hydrophilic mannose on the outside and hydrophobic TLR7/8 agonist inside. Although its ability to stimulate HEK-BlueTMhTLR7/8 cells dropped, it can efficiently stimulate mouse bone marrow-derived dendritic cells as indicated by the up-regulation of CD80 and CD86, and higher cytokine expression levels of TNF-α, IL6, and IL-12p70 than the native TLR7/8 agonist. In vivo, vaccination using the SARS-CoV-2 RBD trimer as the antigen and the conjugate as the adjuvant induced a significantly higher amount of IgG2a. These results suggest that the mannose-TLR7/8-agonist conjugate can be used as an effective vaccine adjuvant.Keywords:adjuvants;mannose;TLR7/8 agonist;immune responses;cytokines;antibody
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DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2021
·
IF 9.381
Mengge Shang,Xinen Zhang,Jing Zhang,Jinqiang Sun,Xinfu Zhao,Shimo Yu,Xiaochan Liu,Benxue Liu,Xibin Yi
Cellulose derived carbon aerogel (CA) with unique three-dimensional network coated with polyaniline (PANI) on its surface is used as a scaffolding framework to anchor ZIF-8. The designed ZIF-8 derived porous carbon (ZC)/PANI@CA (ZPCA) hybrid carbon composite through a facile solution immersion chemical route and subsequent carbonization process is employed as electrode for supercapacitor, which has contributed a large specific surface area, a hierarchical porous structure and reasonable N content (up to 6.27 at.%). The synthesized ZPCA electrode achieves an outstanding capacitance of 388 F g −1 at 0.5 A g −1 as well as an excellent cycling performance. More inspiringly, the symmetric supercapacitor based ZPCA achieves a high energy density of 13.4 Wh kg −1 at a power density of 250 W kg −1 using 2 M KOH aqueous solution, and an ultrahigh energy density of 81.8 Wh kg −1 at a power density of 950 W kg −1 is realized using Et 4 NBF 4 /AN electrolyte.
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PubMed
高影响因子
ACS Applied Nano Materials
·
2020
·
IF 0
Xin Liu,Yinsheng Xu,Qianqian Liu,Wenjun Zhang
Metal–organic frameworks (MOFs) are a platform with multiple luminescent centers resulting from the multifaceted nature of their structure. Herein, via a facile postsynthetic modification method applied to the MOF (1,4-dicarboxybenzene, 2,6-pyridinedicarboxylic acid, and zirconium chloride were used as the linkers and metal precursor), the lanthanide-functionalized hybrid nanomaterial Eu3+/MOF(xHQ) (HQ = 8-hydroxyquinoline) is prepared. Luminescence of the Eu3+/MOF(xHQ) nanomaterial was investigated at the excitation wavelength of 308–365 nm, where there are two kinds of luminescence, that is, the MOF(xHQ) emission and the Eu3+ emission. After studying the luminescence of the MOF(xHQ), the luminescence mechanism, that is, the preferential absorption enhancement (PAE) mechanism, was proposed, to reveal the PAE of the MOF over HQ. Notably, the Eu3+/MOF(xHQ) achieves multicolor emissions by changing the excitation wavelength that shows great potential applications in the field of white light materials and anticounterfeiting. Moreover, the PAE mechanism makes the existing MOF more extensive and opens the strategy to the reasonable design of dimming aspects for this type of MOF materials.
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DOI
JOURNAL OF MEMBRANE SCIENCE
·
2023
·
IF 9.5
Taotao Ji,Jiahui Yan,Yongfu He,Wenjing Hu,Yuan Peng,Weishen Yang,Yi Liu
Despite their huge potential in C 3 H 6 refinement, ZIF-8 membranes still struggle to achieve stable production of high-purity C 3 H 6 , owing to their fluctuant performances under changing operating conditions. In this study, a previous low-temperature synthetic protocol was further optimized to improve the microstructure of ZIF-8 membranes for pressure-resistent C 3 H 6 /C 3 H 8 separation through precisely regulating the reaction temperature between −15 °C and 5 °C. The elevation of reaction temperature gave rise to reduced grain boundary defects at the cost of increased membrane thickness. Of particular note, carrying out reaction between −2.5 °C and 2.5 °C assured an exact balance between upward intergrowth and inner penetration and thus, the formation of well-intergrown semi-confined ZIF-8 membrane featuring pressure-resistant C 3 H 6 /C 3 H 8 separation even at operating temperature as high as 125 °C. At feed pressure of 7 bar, our membrane remained a separation factor approaching 190 with C 3 H 6 permeance up to 2.9×10 -8 mol m -2 s -1 Pa -1 , thus demonstrating the best separation performance under similar test conditions. Moreover, our membrane could maintain a stable separation capacity at C 3 H 6 feed fraction of 1%–99%, which has never been addressed in previous literature. The above stable and outstanding separation performance recommend our membrane a superb choice for reliable batch production of high-purity C 3 H 6 .
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Hanchen Ye,Dongyun Chen,Najun Li,Qingfeng Xu,Hua Li,Jinghui He,Jianmei Lu
The discharge of large amounts of sewage has caused enormous damage to the environment and human health. There is an urgent need for efficient and environmentally friendly materials to deal with such troubles. Materials with emulsion separation have attracted everyone’s attention. In this study, zeolitic imidazolate framework (ZIF)-8- and Co-polydimethylsiloxane (PDMS)-modified multiwalled carbon nanotube films were fabricated. First, the surface of the nanotube films was modified with ZIF-8 by in situ growth, and then a Co-PDMS layer was added by dip coating. The membrane has excellent wettability, and it is superhydrophobic and superoleophilic in air. The separation efficiency of water-in-oil emulsions reaches more than 99.9%, and it has an outstanding separation ability for corrosive emulsions. Moreover, the membrane has an excellent self-healing ability, and it can rapidly heal at normal temperature after being damaged. This makes the film more suitable for practical oily wastewater treatment. We performed related research and propose a possible self-healing mechanism.
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2020
·
IF 7.489
Long Zhou,Na Li,Xiaoying Jin,Gary Owens,Zuliang Chen
A n Fe@ZIF-8 composite, which combined the tailorable porosity of ZIF-8 with the versatile functionality of Fe nanoparticles ( n Fe), was synthesized for Pb(II) removal. Batch adsorption experiments showed that more than 95.3% of Pb(II) was removed from aqueous solution at an initial concentration of 50 mg L −1 when using n Fe@ZIF-8 within 60 min at pH value of 5. The mechanism of Pb(II) removal was studied via characterization of changes the morphology, size and composition of in n Fe@ZIF-8 before and after exposure the solutions containing Pb(II). Specifically, Fourier transform infrared (FTIR) and X-ray powder diffraction (XRD) indicated that n Fe@ZIF-8 was successfully synthesized and also remained stable after Pb(II) removal. Transmission Electron Microscope (TEM) and Scanning electron microscopy-X-ray energy dispersive spectrometer (SEM-EDS) both confirmed that Pb(II) was partially adhered onto the surface of n Fe@ZIF-8, where X-ray photoelectron spectroscopy (XPS) specifically revealed the existence of Pb(0) on the surface. This indicated that Pb(II) was initially adsorbed onto the surface of n Fe@ZIF-8 and subsequently reduced to Pb(0). Moreover, Pb(II) removal fit well to kinetics of absorption and reduction. Finally, in practice, n Fe@ZIF-8 could remove 96.3% of Pb(II) from an electroplating wastewater.
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DOI
高影响因子
Optical Materials Express
·
2022
·Vol. 12
·期 2
·479-488
·
IF 3.074
Jiling Xue,Jiling Xue,Zhaomin Tong,Zhaomin Tong,Yifei Ma,Yifei Ma,Mei Wang,Mei Wang,Suotang Jia,Suotang Jia,Xuyuan Chen,Xuyuan Chen,Xuyuan Chen
Volume scattering diffusers (VSDs) with different thicknesses were fabricated for speckle reduction investigation in a two-diffuser system. The VSDs were obtained by spin-coating the mixture of SiO2 microspheres and SU-8 photoresist, where the monodispersed SiO2 microspheres were synthesized by the Stöber method with an average diameter of 1.43 µm. The Mie scattering effect of the VSDs was observed owing to the refractive index difference between the SiO2 microspheres and the SU-8 photoresist. The speckle reduction effect of the two-diffuser system comprising cascaded stationary and moving VSDs was experimentally studied. The result can be used in designing more effective speckle reduction techniques in laser displays.
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DOI
高影响因子
Canadian Journal of Chemistry
·
2022
·Vol. 100
·期 6
·
IF 1.051
Junyong Sun,Xian Liu,Like Chen,Lijun Peng,Xitian Peng,Tian Gan
Herein, polyvinylpyrrolidone-stabilized Au nanorods were controllably implanted into ZIF-8 to form a well-uniformed AuNRs@ZIF-8 electrocatalyst with a multicore-shell structure. After characterizing the chemical and physical properties, a novel electrochemical sensing platform was fabricated for 2-chlorophenol (2-CP) monitoring based on the AuNRs@ZIF-8 modified glassy carbon electrode. Due to the unique electrochemical property of AuNRs cores and ultra-porous architecture of ZIF-8 shell, the electrocatalyst would effectively accelerate the electron transfer and greatly improve the electrochemical response of 2-CP. Under the optimized experimental conditions, the oxidation peak current of 2-CP enhanced linearly with the increase of its concentration between 0.010 and 40 μM, and the limit of detection was 3.6 nM based on S/N = 3. Meanwhile, the prepared AuNRs@ZIF-8 electrode showed favorable stability, reproducibility, and selectivity, which could be applied to the accurate analysis of 2-CP in aquaculture with standard addition recovery ranging from 96.67% to 104.0%.
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 47
·22133-22140
·
IF 3.591
Huaming Feng,Yang Luo,Ming Liu,Qing Chen,Zhu Tao,Xin Xiao
Cucurbit[n]urils (Q[n]s) are essential members of the supramolecular organic framework family owing to their distinct structure. In this study, Q[8] was employed as a building block and a Q[8]-based porous supramolecular assembly (Q[8]–PSA) was prepared by simple crystallization in an aqueous HCl solution. This Q[8]–PSA was constructed through the outer surface interaction of Q[8] and hydrogen bonding between the lattice water molecules and portal carbonyl oxygens of Q[8]. Q[8]–PSA provides a uniform pore structure, large specific surface area, and uniform pore size, which was characterized by single crystal XRD, TEM, SEM, and FT-IR spectroscopy. Following this, the obtained Q[8]–PSA was employed to evaluate its adsorption property towards 8 drugs with varying shape and size. Moreover, the controlled release of drugs from Q[8]–PSA was also investigated at pH 4.5 and 6.8 using an orbital oscillator.
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DOI
高影响因子
INORGANIC CHEMISTRY
·
2018
·
IF 4.7
Fengqiong Tao,Chaoping Liang,Xiaoming Wang,Xiaohui Li,Florence Porcher,Mathieu Allix,Fengqi Lu,Haoran Gong,Laijun Liu,Xiaojun Kuang
A new 8-layer shifted hexagonal perovskite Ba8MnNb6O24 has been synthesized in air, featuring unusual long-range B-cation ordering with single octahedral high-spin d5 Mn2+ layers separated by ∼1.9 nm within the corner-sharing octahedral d0 Nb5+ host, analogous to Ba8(Zn/Co)Nb6O24. The large size and charge differences between high-spin Mn2+ and Nb5+, as well as the out-of-center distortion of NbO6 octahedra associated with the bonding covalence and second-order Jahn–Teller effect of Nb5+, drive long-range cationic ordering, thus stabilizing Ba8MnNb6O24. The Ba8MnNb6O24 pellet exhibits a high dielectric permittivity, εr ∼ 38, and a large temperature coefficient of resonant frequency, τf ∼ 20 ppm/K, but a dielectric loss (Qf ∼ 987 GHz) and conductivity (∼10–8–10–3 S/cm within 473–1173 K) much higher than those of Ba8ZnNb6O24. Electronic structures from density functional theory calculations reveal that Ba8MnNb6O24 is a Mott insulator in contrast with the charge-transfer insulator nature of Ba8ZnNb6O24, and they confirm that the off-center distortion of Nb5+ contributes to stabilization of the 8-layer ordered shifted structure. The contrast between conductivity and dielectric loss of Ba8MnNb6O24 and Ba8ZnNb6O24 is understood based on the electronic structure that depends on high-spin d5 Mn2+ and d10 Zn2+ cations. The hopping of 3d valence electrons in high-spin Mn2+ to Nb5+ 4d conduction bands over a small gap (∼2.0 eV) makes Ba8MnNb6O24 more conductive than Ba8ZnNb6O24, where the electrons are conducted via the hopping of a lattice O 2p valence electron to the Nb5+ 4d conduction bands over a larger gap (∼3.9 eV). The high microwave dielectric loss of BMN may be mainly ascribed to the half-filled Mn 3d orbits, which is understood based on the softened infrared modes that increase the lattice vibration anharmonicity as well as the resonant spin excitation of unpaired d electrons.
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PubMed
高影响因子
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