查找使用阿拉丁产品的科研文献

Three-dimensional functional carbon nanotube architecture as a highly efficient and active indirect catalyst for degradation of 4-chlorophenol

Yu Feng,Yanan Wang,Zijin Pang,Yunqing Zhuang,Yu-Shi He,Weimin Zhang,Jinglin Mu,Xin Huang

Electro-Fenton (EF) is a promising and green technology for environmental remediation. However, traditional EF often suffers from iron sludge production, leading to poor pH adaptation and secondary pollution. In this work, we synthesized a three-dimensional (3D) carbon nanotube architecture containing nitrogen and oxygen heteroatoms on carbon fibre paper (3D-NOCNTs/CFP) as an indirect catalyst for a metal-free EF process for the removal of 4-chlorophenol (4-CP). The dependence of the content and the type of the functional groups in the carbon plane on the pyrolysis temperature was studied through XPS measurements. This binder-free electrode has been identified as a bifunctional catalyst that can catalyze a high H 2 O 2 yield process and a subsequent in-situ generation of ⋅OH via an O 2 reduction reaction (ORR). Thus the generated ⋅OH radicals can directly participate in the oxidative degradation of 4-CP and the utilization of iron can be avoided in the EF process. The optimized electrode could remove 99.3 % 4-CP in 120 min and exhibits a broad suitability upon pH, an excellent capability, and a prominent stability for the degradation of 4-CP. The mechanism was explained by density function theory (DFT) calculations and the controlled experiments. Such a metal-free EF process features a promising green technology for the oxidative degradation of organic pollutants.

Multifunctional Bacterial Cellulose Nanofibers/Polypyrrole (PPy) Composite Films for Joule Heating and Electromagnetic Interference Shielding

Yingjie Huo,Dan Guo,Jialu Yang,Yukai Chang,Bochong Wang,Congpu Mu,Jianyong Xiang,Anmin Nie,Kun Zhai,Tianyu Xue,Fusheng Wen

Polypyrrole has attracted more and more attention due to its low density, high conductivity, and excellent electro/photothermal conversion ability. However, the poor mechanical properties of polypyrrole limit its further application. In this work, mechanically flexible bacterial cellulose nanofibers/polypyrrole (BC@PPy) composite films were fabricated by in situ polymerization and vacuum filtration. The addition of BC improved the mechanical properties of PPy and made it have good tensile and bending capacity. The conductivity of BC@PPy films could be tuned by the polymerization time of pyrrole. The BC@PPy-6 h film displayed excellent low-voltage-driven Joule heating (up to 95.4 °C at 5 V) and high-efficiency photothermal conversion (up to 52.4 °C under 100 mW/cm2) performance. Moreover, the resultant BC@PPy-6 h film also showed outstanding electromagnetic interference (EMI) shielding effectiveness of exceeding 28.5 dB in the whole X band. Therefore, the multifunctional BC@PPy films possess high application prospects in wearable electrical devices for Joule heating, photothermal conversion, and EMI shielding.

Glutathione responsive nitric oxide release for enhanced photodynamic therapy by a porphyrinic MOF nanosystem

Mengtong Xia,Yu Yan,Haiyan Pu,Xuening Du,Jingyi Liang,Yaning Sun,Jiani Zheng,Yue Yuan

In photodynamic therapy (PDT), the concentration of reactive oxygen species (ROS) generated in cells directly determines the therapeutic effect. However, excessive glutathione (GSH) concentration at the tumor site and hypoxic environment strongly reduce the production of ROS. Nitric oxide (NO) has a variety of anti-tumor activities, including the induction of cell apoptosis and sensitization to PDT, so it is in the spotlight in the area of cancer intervention. Therefore, it is very innovative to combine NO therapy with PDT and simultaneously reduce GSH content and relieve hypoxia. Metal-organic framework (MOF) is an emerging drug delivery vehicle that can exert photodynamic effects when a photosensitizer is used as its organic ligand. In this study, we constructed a GSH-responsive NO producing nanosystem to enhance ROS production through GSH depletion and hypoxia alleviation. Briefly, nicorandil (Nic) is encapsulated into porous porphyrinic MOF nanoparticles, and hyaluronic acid (HA) is electrostatically adsorbed on the surface of the MOF nanoparticles for CD44 receptor-targeting and prevention of Nic leakage. Notably, the Nic reacts with GSH to produce NO gas with vasodilation and GSH reduction, thus improving oxygen supply for efficient ROS generation. Moreover, the generated NO can further react with superoxide radical anion to produce highly reactive peroxynitrite (ONOO − ) molecules with higher cytotoxicity. Overall, the [email protected] nanosystem combines NO gas therapy with PDT, resulting in a significant increase in ROS production and greatly enhancing the efficacy of PDT.

Interpenetrating network structures assembled by “string of candied haws”-like PPY nanotube-interweaved NiCo-MOF-74 polyhedrons for high-performance supercapacitors

Yujuan Cao,Ning Wu,Fan Yang,Meng Yang,Tingting Zhang,Hao Guo,Wu Yang

Due to the insufficient performance, it is still a challenge to combine conventionally synthesized metal-organic framework (MOF-74) with other materials to fabricate composite electrodes for high-performance supercapacitors . Herein, we synthesized a series of NiCo-MOF-74 composite materials with different amounts of polypyrrole nanotubes (T-PPy) denoted as NiCo-MOF-74/T-PPy-m (m = 2.5, 5, 10, 15 and 20) through in situ growth of the bimetallic MOF around the PPy nanotubes by a simple solvothermal method . By comparison, the NiCo-MOF-74(1)/T-PPy-10 composite, with a Ni/Co molar ratio of 1:1 obtained in the presence of 10 mg of T-PPy, possessed the highest specific capacitance of 849 C·g −1 at 1 A·g −1 and excellent cyclic stability with a capacitance retention rate of 90.0% after 10,000 cycles as well as good rate performance. Moreover, the assembled asymmetric supercapacitor respectively using NiCo-MOF-74(1)/T-PPy-10 and active carbon as positive electrode and negative electrode achieved a superior energy density of 58.4 Wh kg −1 at the power density of 747.6 W kg −1 and high cyclic lifespan (91.4% capacitance retention after 10,000 cycles). The mechanism of capacitance increase was studied in detail, influences of metal molar ratios, morphology and addition amounts of PPy on electrochemical performances of the formed composition materials were systematically discussed, and it was found that the interpenetrating network structure assembled by “string of candied haws”-like T-PPy-interweaved NiCo-MOF-74(1) polyhedrons possessed the best capacitive performance for enhanced conductivity of the resulted composite, improved dispersity of the bimetallic MOF and more exposed active sites. And the interwoven structure alleviated the stress change-induced structure or phase variation caused by repeated volumetric swelling and shrinking during charge/discharge cycle and enhanced the rate capability and cycling stability.

Supersensitive detection of chloramphenicol with an EIS method based on molecularly imprinted polypyrrole at UiO-66 and CDs modified electrode

Liyin Bu,Xiaohui Chen,Qingyuan Song,Ding Jiang,Xueling Shan,Wenchang Wang,Zhidong Chen

In this study, a supersensitive electrochemical impedance spectroscopy (EIS) analysis method combined the molecularly imprinted polypyrrole (MIP) which electropolymerized on the composites of zirconium-based metal organic framework (Uio-66) and carbon dots (CDs) modified glassy carbon electrode (GCE) was developed for chloramphenicol (CAP) determination. The integration of Uio-66 and CDs effectively promoted the sensitivity of the proposed MIP senor by improving the surface area and the charge transfer of electrode. By extraction of CAP template, the specific sites were formed on the MIP surface which can rewrap the CAP target molecules. The CAP determination was based on the charge transfer difference (△Rct) before and after the MIP/ [email protected] /GCE rebinding the CAP. The results showed that △Rct responded good linearity to the logarithm of CAP concetration in the range of 0.1 – 100 pmol/L, with a low detection limit of 0.061 pmol/L (S/N = 3), exhibiting high sensitivity and specificity for the determination of CAP.

Methyl orange-crosslinked polypyrrole hydrogel enabled N, O, S co-doped porous carbon for highly sensitive determination of three redox-active biomolecules

Mingzhu Cui,Zhiqiang Xie,Meiling Wang,Xianming Zhang

Development of a high-performance electrode materials for the simultaneous sensing of ascorbic acid (AA), dopamine (DA) and uric acid (UA) is critical in clinical diagnostics. Novel polymer hydrogel-derived porous carbon has been investigated in sensing due to their high conductivity, hierarchical porous structure and environmental benignity. However, the high cost and cumbersome synthesis of the crosslinker for polymer hydrogel precursors make carbon production by pyrolysis greatly compromised. To address this challenge, here, a facile approach to N, O, S co-doped three-dimensional porous carbon frameworks (N, O, S-HCF) derived from methyl orange (MO) crosslinked polypyrrole hydrogel is developed. Experimental and spectroscopy demonstrate that the derived 3D porous structure and heteroatom doping effect create multidimensional electron transfer pathways and electrocatalytic activity centers. Specifically, the sensor exhibits potent and persistent electrochemical behavior with well-separated oxidation peaks and enhanced oxidation peak currents towards ascorbic acid (AA), dopamine (DA) and uric acid (UA). As a result, the N, O, S-HCF contributes to the effective determination of the three analytes in their mixture and the calibration curves show linear range of 2.5 × 10 −6 –1.0 × 10 −2 M, 1.8 × 10 −7 –8.7 × 10 −5 M, and 2.5 × 10 −7 –1.0 × 10 −4 M with detection limits of 1.0 × 10 −6 , 1.2 × 10 −7 , and 1.8 × 10 −7 M for AA, DA and UA, respectively. This study provides a simple strategy to build heteroatom doped porous carbon for the simultaneous monitoring of multiple electroactive species.

Polypyrrole Decorated Flower-like and Rod-like ZnO Composites with Improved Microwave Absorption Performance

Leilei Zhang,Yihua Lv,Xiaoyun Ye,Lian Ma,Song Chen,Yuping Wu,Qianting Wang

In this study, zinc oxide (ZnO)/polypyrrole (PPy) composites with flower- and rod-like structures were successfully fabricated by in situ polymerization and the hydrothermal method and used as microwave absorption (MWA) materials. The surface morphologies, crystal structures, and electromagnetic features of the as-prepared samples were measured by field-emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and vector network analyzer (VNA). The results show that the conductive polymer PPy was successfully decorated on the surface of ZnO substrates. The MWA ability of flower- and rod-like ZnO/PPy composites is significantly enhanced after introduction of PPy. Rod-like ZnO/PPy composites exhibited superior MWA properties than those of flower-like ZnO/PPy. The former achieved a minimum reflection loss (RLmin) of −59.7 dB at 15.8 GHz with a thickness of 2.7 mm, and the effective absorption bandwidth (EAB,RL< −10 dB) covered 6.4 GHz. PPy addition and stacked structure of rod-like ZnO/PPy composites can effectively improve the dielectric properties, form multiple reflections of incident electromagnetic waves, and generate an interfacial polarization effect, resulting in improved MWA properties of composite materials.Keywords:ZnO;polypyrrole;composites;microwave absorption;dielectric loss

Chidamide stacked in magnetic polypyrrole nano-composites counter thermotolerance and metastasis for visualized cancer photothermal therapy

Sizhen Wang,Zhiqiang Ma,Zhang Shi,Ying Huang,Tianheng Chen,Lei Hou,Tao Jiang,Feng Yang

Tellurium: A High-Performance Cathode for Magnesium Ion Batteries Based on a Conversion Mechanism

Ze Chen,Qi Yang,Donghong Wang,Ao Chen,Xinliang Li,Zhaodong Huang,Guojin Liang,Ying Wang,Chunyi Zhi

Magnesium ion batteries (MIBs), due to the low redox potential of Mg, high theoretical capacity, dendrite-free magnesiation, and safe nature, have been recognized as a post-lithium energy storage system. However, an ongoing challenge, sluggish Mg2+ kinetics in the small number of available cathode materials of MIBs, restricts its further development. The existing cathodes mostly deliver unsatisfactory capacity with poor cycling life based on the traditional ion-intercalation mechanism. Herein, we fabricated a conversion-type Mg∥Te battery based on a reversible two-step conversion reaction (Te to MgTe2 to MgTe). High discharge capacities (387 mAh g–1) and rate capability (165 mAh g–1 at 5 A g–1) can be achieved. The diffusivity of Mg2+ can reach 3.54 × 10–8 cm2 s–1, enabled by the high electrical conductivity of Te and increased surface conversion sites. Subsequently, ab initio molecular dynamics simulation was also carried out to further confirm the conversion mechanism and fast Mg2+ transportation kinetics.

Constructing an artificial boundary to regulate solid electrolyte interface formation and synergistically enhance stability of nano-Si anodes

Chunyue Zhou,Xuzhong Gong,Yueke Feng,Jijun Lu,Yulong Fu,Zhi Wang,Junhao Liu

Low coulombic efficiency and poor cyclic stability are two common problems for silicon anodes. Therefore, it is of great significance to improve cycling performance and initial coulombic efficiency (ICE) via rational surface engineering on nano-Si anodes. Herein, a new nano-silicon anode is obtained by straightforward constructing a multifunctional polypyrrole protective layer on the surface of silicon nanoparticles , which is further used as the inner boundary of solid electrolyte interface (SEI) film. Specifically, the Li salt decomposition reaction between the electrolyte and silicon surface is effectively inhibited under the protection of the compact artificial boundary. The transfer of Li + for forming the SEI film is selectively slower than that of lithiation/delithiation reaction. This further reduces the amount of SEI film, leading to a high ICE of 93.2% at 0.5 A g −1 for modified nano-Si anodes. In addition, the flexible SEI precursor combined with the high proportion of organic components in SEIs not only accommodates the volume change of nano-silicon, but also suppresses accumulation of “waste SEI”, so the electrode can maintain a reversible capacity of 1153.2 mAh g −1 at 1 A g −1 after 500 cycles. This work provides important guidance for surface structural optimization of alloy-type anodes with high volume change.

B, N stabilization effect on multicavity carbon microspheres for boosting durable and fast potassium-ion storage

Lantao Liu,Yaping Lu,Shuaize Wang,Yinghui Ding,Yaxin Chen,Daping Qiu,Dengke Wang,Jin Niu,Jiapeng Zhang,Xiaohong Chen,Huaihe Song

Heteroatom-rich carbon materials deliver superior potassium storage capacity owing to the abundant active sites, but their stability and conductivity are damaged because of the numerous defects and distortion of π-conjugated system. In this work, we amended the adverse influences of heteroatoms on carbon materials through the B, N stabilization effect. Due to an amending effect of B atoms on the N -doped carbon matrix, the integrity of the carbon skeleton and stability of the system are significantly enhanced, and the undesirable defects are transformed into favorable active sites, resulting in the simultaneous improvement of K + storage capacity, rate performance and cyclic stability. The stabilized materials have a highly reversible carbon structure and fast K + transfer kinetics, leading to high reversible capacity (300 mA h g −1 at 0.1 A g −1 ), good rate performance (107.2 mA h g −1 at 10 A g −1 ) and superior cyclic stability (75.3 % capacity retention from cycle 11 to 2000 at 1 A g −1 ). Consequently, the constructed devices perform excellent energy densities of 158.8 and 40.7 Wh kg −1 under power densities of 100 and 11250 W kg −1 , respectively. This work proposes an effective strategy for significantly improving heteroatom-rich carbon materials, which broadens its application fields in high-performance potassium ion storage.

Solar-Boosted Paper-Based Microfluidic Fuel Cells for Miniaturized Power Sources

Wei Wang,Liu-Liu Shen,Hui Yu,Wenkai Xu,Jiansong Wang,Cong Yong,Gui-Rong Zhang,Donghai Mei

Paper-based microfluidics emerges as an innovative platform for constructing miniaturized electrochemical devices, which mainly benefit from the spontaneous capillary action of paper. Nevertheless, the capillary-driven flow dynamics on paper are determined exclusively by the intrinsic properties of paper and fluidics, thus lacking the controllability that conventional pump-based microfluidics can provide. Herein, an approach to regulating the capillary flow on paper is introduced by conjugating the outlets of microfluidic channels with a photothermal module for water evaporation. The capillary flow rate on paper can be handily regulated from 4 to 37 µL min −1 under controllable illumination conditions. As a proof-of-concept, prototypical paper-based microfluidic fuel cells integrated with the photothermal module are constructed. Their peak power density can be boosted from 0.3 up to 2.1 mW cm −2 under the simulated sunlight irradiation. The influence of capillary flow rate on the fuel cell performance is further validated using multiphysics simulations. The present work not only provides a practically feasible method to boost the performance of paper-based microfluidic fuel cells using solar energy, but also opens a new avenue for modulating the performance of paper-based microfluidics, which has long been a challenge in this field.