Electrically conductive porous metal-organic frameworks (MOFs) exhibit a huge potential in a broad range of applications. However, how to endow MOFs with appropriate electrical conductivity remains a ...challenge. In this paper, we report a controllable growth of polypyrrole (PPy) nanofibers in the nanochannels of MOFs to construct a kind of nanocomposites. We can also use this strategy to directly demonstrate the straight nanochannel structure in MOFs. More importantly, the formed PPy/ZIFs nanocomposites show a highly tunable electrical conductivity as well as a tunable electromagnetic absorption (EMA) property. The maximal frequency width with absorbing higher than 90% of incident electromagnetic waves reaches 7.24 GHz, which is wider than those of most reported MOFs or conducting polymers based EMA materials. An electrical conductance loss and interfacial polarization relaxation are used to investigate the electromagnetic dissipation mechanism of theses PPy/ZIFs nanocomposites. It opens up the rational design of electrically conductive MOFs for excellent electromagnetic absorption.
Display omitted
The authors describe the synthesis of carbon dots (CDs) that are highly doped with both nitrogen and phosphorus. Synthesis is accomplished via a hydrothermal reaction starting from ...diethylenetriaminepenta(methylenephosphonic acid) and m-phenylenediamine as the precursors. The high
N,P
-doping ratios renders the codoped CDs excellently water soluble, photostable over a wide range of pH values, and photostable in the presence of various metal ions. Ferric ions acts as a strong quencher of fluorescence. Their low cytotoxicity and strong green fluorescence (with excitation/emission peaks at 440/510 nm and a quantum yield of 0.32) make the CDs well suited for purposes of cell imaging, and this is demonstrated by fluorescent bioimaging of human lung carcinoma cells (type A549) and human breast cancer cells (type KB). Furthermore, the CDs were used as an effective probe for monitoring Fe(III) in both aqueous solution and living cells.
Graphical abstract
A highly
N,P
-codoped carbon dots (CDs) were synthesized for high-quality cellular Imaging and monitoring Fe
3+
in living cells. This water soluble CDs displayed high biocompatibility and emitted strong green fluorescence.
Display omitted
•Mussel-inspired magnetic pullulan (MMP) hydrogels were synthesized.•MMP hydrogels were for the first time used as Fenton-like catalysts.•MMP hydrogels exhibited excellent degradation ...activity, reusability and stability.•Detailed degradation mechanism for tetracycline in our MMP4/H2O2 system was proposed.
Magnetic hydrogels are fascinating materials that can be used as Fenton-like catalysts to remove antibiotics from biomedical wastewater. However, the poor distribution of magnetic nanoparticles in hydrogel matrix and weak mechanical properties severely confine their applications from lab to industrial scale. Here, we presented for the first time the facile fabrication of mussel-inspired magnetic pullulan (MMP) hydrogels using polydopamine as a bridge to build a relationship between Fe3O4 and pullulan matrix, which could solve the common problems of magnetic hydrogels and enhance catalytic degradation of tetracycline (TC) simultaneously. Degradation results proved that our catalytic system (MMP4) showed superior TC degradation efficiency (86.32% within 60 min). Theoretical studies verified that TC could act as an electron donor and the produced electrons from TC were transferred via polydopamine to the iron species through π-Fe interactions. Besides, MMP4 exhibited excellent reusability and stability that no apparent decrease in degradation efficiency was observed after 5 cycles. Altogether, our findings provide a simple but effective strategy to design magnetic hydrogel catalysts for enhancing antibiotic degradation from biomedical wastewater.
Electrical conductivity and interfacial polarization are two crucial factors to design high-performance electromagnetic absorption (EMA) materials, but how to synergistically balance these factors ...still remains to be difficult. In this work, we report the synthesis of Cu/C nanocomposites via the controlled pyrolysis of a MOF-guest complex. The prepared Cu/C nanocomposites are made up of cross-linked carbon network and various irregular particles. The carbon network provides appropriate electrical conductivity to contribute to the conductance loss. Multiple heterogeneous interfaces, such as Mo2C/C, Mo2C/CuO, CuO/C, Mo2C/Cu, and Cu/C interfaces, have been determined in these Cu/C nanocomposites, resulting in obviously improved polarization loss. As a result, the Cu/C nanocomposite exhibits excellent EMA performance, where the efficient absorption bandwidth reaches 6.8 GHz, and the maximal absorption gets to −52 dB. This research provides new idea to design high-performance EMA nanocomposites by tuning the electrical conductivity and interfacial polarization.
Display omitted
Fenton-like catalysts represent a family of promising materials to degrade micropollutants from contaminated water. However, the practical applications of Fenton-like catalysts are mainly limited by ...low catalytic degradation efficiency and stability. Herein, for the first time, rapid fabrication of Ag-decorated Fe3O4/polydopamine (FPA) microspheres was achieved via the help of UV irradiation, and the designed FPA microspheres were employed as Fenton-like catalysts to degrade micropollutants. Results showed that UV irradiation could activate the generation of the polydopamine shell and accelerate the Ag deposition, which played a crucial role in the rapid synthesis of highly active and stable FPA catalysts. Relative to reported catalysts, these FPA microspheres exhibited outstanding catalytic degradation performance, achieving 94.38% removal of tetracycline within 60 min. This work will provide a convenient strategy in the sustainable and efficient purification of wastewater to improve the quality of human life.
Display omitted
•Rapid synthesis of Fe3O4/polydopamine/Ag (FPA) microspheres was achieved.•FPA microspheres were used as Fenton-like catalysts for the first time.•FPA exhibited outstanding catalytic degradation performance and stability.•Detailed degradation mechanism of FPA for degrading tetracycline was described.
Conductive conjugated microporous polymers (CMPs) were prepared by a micropore-confined polymerization strategy, and show excellent electromagnetic waves absorption performance.
Display omitted
...•Confined polymerization of pyrrole monomer in micropores (diameter ≤ 2 nm)•Conductive conjugate microporous polymers (CMPs) was synthesized.•Conductive CMPs show enhanced dielectric loss toward microwaves.•Maximum effective absorbing width of conductive CMPs reaches 7.52 GHz.
Endowing conjugate microporous polymers (CMPs) with appropriate electrical conductivity greatly expands the application scope of CMPs, especially in electronic-related applications. In this paper, we report a strategy to prepare electrically conductive CMPs via confined polymerization of pyrrole in micropores. The conductive CMPs shows remarkably enhanced dielectric loss behaviors toward microwaves, and exhibits high electromagnetic absorption (EMA) performance, where the effective EMA bandwidth reaches 7.52 GHz and the maximal absorption achieves −59.7 dB. A confining model is adopted to explain the reason for the enhanced dielectric loss of conductive CMPs. This research expands application scope of CMPs in areas of conductive materials.
Display omitted
•Novel magnetic pullulan (MP) hydrogels were designed.•These prepared MP hydrogels were for the first time used as Fenton-like catalysts.•MP hydrogels exhibited excellent degradation ...activity, reusability and stability.•Degradation mechanism for tetracycline hydrochloride in our MP3/H2O2 system was proposed.
Magnetic nanoparticles that can be employed as Fenton-like catalysts Fenton-like catalysts are attractive materials for degrading antibiotics. In this study, we facilely prepared novel magnetic pullulan (MP) hydrogels by doping modified magnetic nanoparticles into pullulan matrices, which could enhance catalytic degradation performance and strengthen the stability of resulting hydrogels. This is the first time that MP hydrogels have been fabricated successfully and used as Fenton-like catalysts for tetracycline hydrochloride (TCH) degradation. MP hydrogels were characterized and their catalytic TCH degradation abilities were also investigated. The optimized conditions (pH value, Fe3O4 content, H2O2 content and TCH concentration) for TCH degradation were investigated. The optimized system showed excellent degradation efficiency for TCH. Further, the degradation mechanism was comprehensively studied. Finally, synthesized MP hydrogels showed impressive reusability and stability in the cycle experiment. Thus, our findings would open new possibilities to develop magnetic hydrogels in eliminating antibiotic contaminants.
Efficient tuning of electrical and magnetic property of a material is of great importance in its functional material design, mechanism understanding, and application expanding. In this work, we ...propose an efficient strategy for the electromagnetic absorption (EMA) behavior regulation of bimetallic polyphthalocyanine (PPc) derived CoFe-alloy/C nanocomposites. Through the adjusting of calcination temperature and Fe/Co atomic ratio, the microstructure (0D/2D nanocomposite), electrical conductivity, magnetic property, and EMA behavior can be efficiently tuned. After optimization, the efficient absorption bandwidth of CoFe-alloy/C achieves 7.64 GHz, while the maximal absorption gets close to −60 dB, exhibiting superiority to most reported carbon related materials. It is thought that the absorbing mechanism of CoFe-alloy/C is mainly ascribed to the combination of conductance loss, multiple polarization, resonance phenomenon, and hysteresis loss. This research greatly expands the application scope of PPc derivatives, and provides an efficient way to understand the interaction between material and electromagnetic waves.
Display omitted
•CoFe-Alloy/C 0D/2D nanocomposites were constructed from bimetallic polyphthalocyanines.•Electromagnetic absorption behavior was regulated by calcination temperature and Co/Fe ratio.•The efficient absorption bandwidth gets to 7.64 GHz at 2.4 mm.•Absorbing mechanism combines conductance, polarization, resonance, and hysteresis.
•Sulfonate-grafted CMPs exhibit fast adsorption capacity on aqueous dyes.•The maximum adsorption of sulfonate-grafted CMPs on cationic dyes reaches 1650 mg/g.•Sulfonate-grafted CMPs absorb 97% of MB ...(100 mg/L) in 25 min.
Conjugated microporous polymers (CMPs) have gained great attention because of high surface area and permanent pores with good gas adsorption capability, but most of them are hard to disperse in water, and thus barely used in sewage disposal. Herein, we adopt sulfonation to post-synthesis sulfonate-grafted CMPs which possess unexceptional dispersity in water. The sulfonate-grafted CMPs also exhibit fast adsorption towards cationic dye solutions especially methylene blue (MB, maximum adsorption up to 1650 mg/g). Because of the porous structure, MB molecules interact with CMPs not only on the surface but also in pores, increasing the contact sites and adsorption efficiency. This research greatly expands the exploration and application scope of CMPs.
Display omitted
•Sulfonated conjugated microporous polymer (S-CMP) with high fluorescence.•S-CMP exhibits excellent water dispersibility and obvious solvatochromic behavior.•Orthogonal sensor array ...for high-throughput differentiation of twelve metal ions.•Organic small molecules are differentiated by the sensor array.
The development of fluorescent sensors for highly sensitive detection of multiple environmental contaminants is highly promising, but still remains to be a challenge up to date. In this work, we provide a highly water-dispersible sulfonated conjugated microporous polymers (S-CMP) based fluorescent sensor array that can be used for high-throughput detection of multiple organic/inorganic contaminants. This S-CMP was synthesized via a two-step process, including a Pd-catalyzed coupling reaction and a sulfonation process. It is differentiated twelve metal ions using principal component analysis (PCA) on the basis of distinguished fluorescent responses of the sensor array on metal ions. Moreover, it is also identified a series of or;1;ganic solvents by this S-CMP-based sensor by virtue of its unique fluorescence-emitting and color response. This work opens up the design of sulfonate-grafted CMP in environmental pollution detection and expands the application scope of CMP.
