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1.
J Colloid Interface Sci ; 659: 959-973, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38219314

RESUMO

Bimetal atom catalysts (BACs) hold significant potential for various applications as a result of the synergistic interaction between adjacent metal atoms. This interaction leads to improved catalytic performance, while simultaneously maintaining high atomic efficiency and exceptional selectivity, similar to single atom catalysts (SACs). Bimetallic site catalysts (M2ß12) supported by ß12-borophene were developed as catalysts for electrocatalytic carbon dioxide reduction reaction (CO2RR). The research on density functional theory (DFT) demonstrates that M2ß12 exhibits exceptional stability, conductivity, and catalytic activity. Investigating the most efficient reaction pathway for CO2RR by analyzing the Gibbs free energy (ΔG) during potential determining steps (PDS) and choosing a catalyst with outstanding catalytic performance for CO2RR. The overpotential required for Fe2ß12 and Ag2ß12 to generate CO is merely 0.05 V. This implies that the conversion of CO2 to CO can be accomplished with minimal additional voltage. The overpotential values for Cu2ß12 and Ag2ß12 during the formation of HCOOH were merely 0.001 and 0.07 V, respectively. Furthermore, the Rh2ß12 catalyst exhibits a relatively low overpotential of 0.51 V for CH3OH and 0.65 V for CH4. The Fe2ß12 produces C2H4 through the *CO-*CO pathway, while Ag2ß12 generates CH3CH2OH via the *CO-*CHO coupling pathway, with remarkably low overpotentials of 0.84 and 0.60 V, respectively. The study provides valuable insights for the systematic design and screening of electrocatalysts for CO2RR that exhibit exceptional catalytic performance and selectivity.

2.
Phys Chem Chem Phys ; 26(3): 1671-1683, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38126187

RESUMO

To tackle the aggravating electromagnetic wave (EMW) pollution issues, high-efficiency EMW absorption materials are being urgently explored. The FeSiCr soft magnetic alloy is one of the more widely used and well-received iron-based soft magnetic alloy materials with high permeability; however, the development of high-performance FeSiCr alloy wave-absorbing materials is still a major challenge. In this study, double core-shell-structured composites of MIL-88(Fe)@Fe2O3@FeSiCr were successfully prepared by the oxidative heat treatment of the flaky FeSiCr obtained after ball milling and then in situ composited with MIL-88(Fe). The heterogeneous interfacial composition and microstructure were regulated to balance the microwave-loss capability and impedance matching of the material, and an enhancement of the composite absorbing performance was achieved. The composite material had a reflection-loss minimization (RLmin) of -72.65 dB, corresponding to a frequency of 6.61 GHz, with an absorbing coating thickness of 2.97 mm and an effective absorbing bandwidth (RL ≤ -10 dB) of 2.38 GHz (5.42-7.80 GHz). The results of this study provide useful ideas for wave-absorbing materials by applying high permeability soft magnetic alloy micropowders.

3.
J Chem Phys ; 159(16)2023 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-37888760

RESUMO

Carbon-based Materials have been extensively researched for their prospect in the fields of environment and energy, especially for graphene oxide (GO). In this work, a novel sodium dodecyl sulfate (SDS)-assisted synthesis of BiOBr/Bi2WO6/GO ternary composite has been synthesized successfully by a handy hydrothermal method. Photoluminescence, Photocurrent, Electrochemical Impedance Spectroscopy, surface photovoltage and transient photovoltage measurements illustrate that construction of p-n BiOBr/Bi2WO6 heterojunction leads to the obviously enhancement of charge separation efficiency, and the photogenerated electrons trapped by GO can effectively inhibit the recombination process of photogenerated charge, resulting in the improvement of charge separation efficiency and the longer lifetime of photogenerated carriers for BiOBr/Bi2WO6/GO. The characterization of structure and morphology indicate that role of GO can also improve the visible light absorption range, and the SDS-assisted synthesis can reduce the size of particle in the composite and enhances the specific surface area of the composite by regulating the particle size and agglomeration. Under optimal conditions, BiOBr/Bi2WO6/GO (SDS) has the outstanding photocatalytic degradation performance and the degradation rate constants for oxytetracycline, tetracycline hydrochloride, methylene blue and rhodamine are 0.056, 0.057, 0.103 and 0.414 min-1, respectively. Notably, the degradation rate constants obtained by BiOBr/Bi2WO6/GO (SDS) are more ten times higher than that of pure BiOBr and Bi2WO6. The possible mechanism of photocatalytic degradation was suggested for BiOBr/Bi2WO6/GO based on the dynamic properties of photogenerated charge and reactive oxidation species results. Surprisingly, the recyclability of the BiOBr/Bi2WO6/GO (SDS) composite obtained from the cyclic experiments has laid a foundation for the study of efficient and stable photocatalysts.

4.
J Colloid Interface Sci ; 649: 510-518, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37356152

RESUMO

Electrochromic materials (ECMs) could exhibit reversible color changes upon application of the external electric field, which exhibits huge application prospects in smart windows, energy storage devices, and displays. For the practical application of ECMs, the fast response speed and long cyclic stability are urgent. In this work, the nanoporous Sm-doped WO3 (WSm) films were constructed using hydrothermal technology, then polydopamine (PDA) was modified on the surface of WSm film to obtain the WSm/Px (x = 0.25, 0.5, 1.0, and 2.0) hybrid films. WSm/Px hybrid films displayed high optical contrast and large areal capacitance. In addition, in comparison with WSm film, the WSm/Px hybrid films exhibited faster response speed and better cyclic stability because PDA film enhanced the interface ion transport ability and electrochemical structural stability of the nanoporous WSm film. Notably, the WSm/P1.0 hybrid film displayed the colored/bleached times of 7.4/2.9 s, retained 90.2% of the primitive optical contrast (68.5%) after 5000 electrochromic cycles. Furthermore, the areal capacitance of WSm film could be increased by 224% through the modification of the PDA. Therefore, WSm/Px hybrid films are great prospects for electrochromic energy-saving and storage windows.

5.
Nanomaterials (Basel) ; 12(12)2022 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-35745441

RESUMO

Perovskite solar cells (PSCs) are currently attracting a great deal of attention for their excellent photovoltaic properties, with a maximum photoelectric conversion efficiency (PCE) of 25.5%, comparable to that of silicon-based solar cells. However, PSCs suffer from energy level mismatch, a large number of defects in perovskite films, and easy decomposition under ultraviolet (UV) light, which greatly limit the industrial application of PSCs. Currently, quantum dot (QD) materials are widely used in PSCs due to their properties, such as quantum size effect and multi-exciton effect. In this review, we detail the application of QDs as an interfacial layer to PSCs to optimize the energy level alignment between two adjacent layers, facilitate charge and hole transport, and also effectively assist in the crystallization of perovskite films and passivate defects on the film surface.

6.
Sci Total Environ ; 824: 153844, 2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-35176366

RESUMO

Water resources have long been of interest to humans and have become a serious issue in all aspects of human life. The disposal of hazardous pollutants in water resources is one of the biggest global concerns and poses many risks to human health and aquatic life. Therefore, the control of hazardous pollutants in water resources plays an important role, when it comes to evaluating water quality. Due to low toxicity, good electrical conductivity, facile functionalization, and easy preparation, magnetic materials have become a good alternative in recent years to control hazardous pollutants in water resources. In the present study, the idea of using magnetic sensors in controlling and monitoring of pharmaceuticals, pesticides, heavy metals, and organic pollutants have been reviewed. The water pollutants in drinking water, groundwater, surface water, and seawater have been discussed. The toxicology of water hazardous pollutants has also been reviewed. Then, the magnetic materials were discussed as sensors for controlling and monitoring pollutants. Finally, future remarks and perspectives on magnetic nanosensors for controlling hazardous pollutants in water resources and environmental applications were explained.


Assuntos
Poluentes Ambientais , Água Subterrânea , Praguicidas , Poluentes Químicos da Água , Monitoramento Ambiental , Humanos , Fenômenos Magnéticos , Recursos Hídricos
7.
Nanoscale ; 13(36): 15471-15480, 2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34515273

RESUMO

Rare earth (RE) materials such as neodymium (Nd) and others consist of unique electronic configurations which result in unique electronic, electrochemical, and photonic properties. The high temperature (>1100 °C) growth and low active surface areas of REs hinder their use as an efficient electrocatalyst. Herein, different morphologies of Nd were successfully fabricated in situ on the surface of graphene using a double-zone chemical vapor deposition (CVD) method. The morphology of the Nd material on graphene is controlled, which results in the significant enhancement of the large specific surface area and electrochemical active area of the composite material due to the spatial morphology of Nd, thereby improving the hydrogen evolution reaction (HER) performance in an alkaline medium. The significantly enhanced HER activity with an overpotential of 75 mV and a Tafel slope of 95 mV dec-1 at a current density of 10 mA cm-2 is observed in Nd-GF. Mainly, a high specific surface area of ∼2217 cm2 g-1 and the porosity of graphene play major roles in the enhancement of activity. Thus, the present work provides a new strategy for the neodymium engineering synthesis of efficient rare earth-graphene composite electrocatalysts with a high electrochemical active area.

8.
Phys Chem Chem Phys ; 23(12): 7145-7152, 2021 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-33876080

RESUMO

Surface properties of all-inorganic halide perovskites play a crucial role in determining optoelectronic performance of these materials. We investigate the surface energies and electronic structures of cubic CsPbBr3 surfaces systematically using density functional theory (DFT) methods. We calculate the surface phase diagrams of low-index surfaces of CsPbBr3, i.e., (100), (110), (111) surfaces. We found that nonpolar (100) surfaces are more stable than polar (110) and (111) surfaces. The nonpolar CsBr-terminated (100) surface shows the best stability, which is attributed to the effect of surface relaxation and high ionicity of the surface layer. The electronic structures reveal that charge transfer to compensate the polarity raises the energy of polar surfaces, which makes polar surfaces unstable. Furthermore, we found that the modulation of surface chemical composition provides an effective way to compensate polarity and thus make polar surfaces of CsPbBr3 stable. Our results provide physical insights into understanding and further enhancing the surface stability of all-inorganic halide perovskites. This would be helpful in promoting the advancement of all-inorganic halide perovskite-based materials and devices.

9.
RSC Adv ; 11(6): 3333-3341, 2021 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-35424291

RESUMO

A Z-scheme system In2S3/WO3 heterojunction was fabricated via a mild hydrothermal method and further applied for photocatalytic degradation of tetracycline (TCH) and Rhodamine B (Rh B) under visible light irradiation. The morphological structure, chemical composition and optical properties were studied by XRD, SEM, HRTEM and UV-visible absorption spectra. The results revealed that In2S3/WO3 hierarchical structures were successfully constructed, and the prepared In2S3/WO3 photocatalysts exhibited enhanced visible-light absorption compared to pure WO3 nanorods, which are essential to improve the photocatalytic performance. The degradation rate of TCH using the In2S3(40 wt%)/WO3 heterostructure (WI40) photocatalyst was about 212 times and 22 times as high as that for pure WO3 and pure In2S3, respectively. The degradation rate of Rh B with the WI40 photocatalyst was about 56 times the efficiency of pure WO3 and 7.6 times that of pure In2S3. The results of the surface photovoltage (SPV), transient photovoltage (TPV) and reactive oxidation species (ROS) scavenger experiments indicated that the Z-scheme system of In2S3/WO3 is favorable for photoexcited charge transfer at the contact interface of In2S3 and WO3, which benefits the charge separation efficiency and depresses the recombination of photoexcited charge, resulting in favorable photocatalytic pollutant degradation efficiency under visible light irradiation.

10.
ACS Appl Mater Interfaces ; 12(46): 51418-51427, 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33156600

RESUMO

Exploring an efficient and pollution-free hydrogen evolution reaction (HER) electrocatalyst based on the combination of rare-earth metal and nonnoble metal is of significant importance. However, successfully achieving such a goal remains highly challenging. Herein, a nanosheet comprising a MoO2-CeF3 heterojunction (MoO2-CeF3/NF) is successfully prepared via a three-step method. (1) Growth of hexahedral nickel hydroxide [Ni(OH)2] on a 3D nickel foam (NF) as the scaffold. (2) In situ hydrothermal growth of a precursor nanosheet structure on the scaffold. (3) Calcination treatment at 450 °C in the presence of hydrogen. Herein, the electron redistribution at the heterointerface of CeF3 and MoO2 is a contributing factor toward enhanced HER activity. Appropriate introduction of CeF3 can enlarge the size of nanosheets, increase numerous active sites, increase the catalytic durability of the material, and change electron distribution on the MoO2 interface; all of the above improve HER activity. Because of its interfacial nanosheet structure, MoO2-CeF3/NF demonstrates pre-eminent HER capability in both alkaline (1.0 M KOH) and acidic (0.5 M H2SO4) electrolytes, with extremely small overpotentials of 18 and 42 mV at 10 mA cm-2, respectively. This is obviously lower than the overpotential of Pt/C in alkaline media (27 mV), and it is also close to the overpotential of Pt/C in acidic media (41 mV), at the same current density. More importantly, MoO2-CeF3/NF displays a better HER activity than Pt/C at a current density of >112 mA cm-2 in both alkaline and acidic electrolytes. This work offers a novel strategy toward high-performance hydrogen production by designing a transition metal oxide and rare-earth metal heterojunction.

11.
Phys Chem Chem Phys ; 22(44): 25712-25719, 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33146207

RESUMO

Graphene, purely sp2-hybridized, has already been extensively studied for magnetoelectronics, however, the magnetotransport properties of graphene fibers (GrFib) have not been explored very well to date. Herein, unique magnetotransport properties of graphene fibers are detected. All the GrFib-samples show the highest positive magnetoresistance (MR ∼ 60%) at room temperature (300 K) that gradually decreases (MR ∼ 37%) at low temperature (5 K), indicating quite different behavior for a graphene derivative. The MR of three different morphologies are compared: single graphene sheet (60-100% at 300 K and 100-110% at 5 K under an applied magnetic field of 5 T), graphene foam (GF-100% at 300 K and 158% at 5 K under an applied magnetic field of 5 T), and graphene fiber (60% at 300 K and 37% at 300 K under an applied magnetic field of 5 T), and found that each morphology has a different magnitude of MR under similar magnitude of magnetic field and temperature. Unlike graphene and GF, GrFib shows a decreasing trend of MR at low temperatures, violating commonly used weak anti-localization phenomena in graphene. Technologically, each morphology of graphene has a unique set of magnetotransport properties that can be considered for particular magnetoelectronic devices depending upon the mechanical, electrical, and magnetotransport properties.

12.
ACS Omega ; 5(33): 21203-21210, 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32875256

RESUMO

In recent decades, great expectation has always been placed on catalysts that can convert toxic CO into CO2 under mild conditions. The catalytic mechanism of CO oxidation by Mn-coordinated N-doped graphene with a single vacancy (MnN3-SV) and a double vacancy (MnN3-DV) was studied by density functional theory (DFT) calculations. Molecular dynamics simulations showed that CO2 on MnN3-SV could not be desorbed from the substrate and MnN3-SV was not suitable for use as a CO oxidation catalyst. MnN3-DV was more suitable for CO oxidation (COOR) and from the electronic structure it was found that the Mn atom was the main active site, which was the reaction site for CO oxidation. At temperatures of 0 and 298.15 K, CO oxidation on MnN3-DV via the Langmuir-Hinshelwood (LH) mechanism was the best reaction pathway. The rate-determining step using MnN3-DV as the catalyst for CO oxidation through the LH mechanism was O2 + CO → OOCO, and the energy barrier was 0.861 eV at 298.15 K. MnN3-DV was suitable as a catalyst for CO oxidation in terms of both thermodynamics and kinetics. This study provides a comprehensive understanding of the various reaction mechanisms of CO oxidation on MnN3-DV, which is conducive to guiding the development and design of efficient catalysts for CO oxidation.

13.
ACS Omega ; 5(7): 3376-3388, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-32118152

RESUMO

Herein, Ni-W alloy matrixes were successfully fortified with two salen-type Schiff bases 1-((E)-(2-((E)-(2-hydroxynaphthalen-1-yl)methyleneamino)phenylimino)methyl)naphthalen-2-ol (OPD) and 1-((E)-(2-((E)-(2-hydroxynaphthalen-1-yl)methyleneamino)phenylimino)methyl)naphthalen-2-ol (PPD) as additives, of similar molecular structure but varied isomeric spacers, using a facile direct current electrodeposition technique. The resulting coatings from the additive-introduced reaction system were termed as Ni-W/OPD and Ni-W/PPD throughout the study. The deterioration process (0.5 M H2SO4), surface properties, elemental composition, functional groups, and structurs of the resultant coatings were analyzed by means of Tafel and electrochemical impedance spectroscopy, field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy, atomic force microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction (XRD). The bare Ni-W alloy deposition resulted in a loose microstructure with higher porosity density (12.2%), while that of additive-doped plating electrolytes resulted in a compact and dense microstructure with lesser porosity density (6.3%) and minimal porosity density (3.7%) as for Ni-W/OPD and Ni-W/PPD alloy coatings, respectively. Improved corrosion parameters presented superior corrosion characteristics of Ni-W alloy coatings from an additive (PPD)-induced bath, i.e., Ni-W/PPD. Synergetic adsorption of imine groups (N atoms), hydroxyl groups (O atoms), and aromatic electron clouds and reduction in steric hindrance produced by a larger isomeric spacer strengthened the surface adsorption of additives, yielding a fine nanocrystalline Ni-W coating with reduced porosity and well-refined grains, implying the outstanding shielding effect. Results of FESEM, AFM, and XRD analyses revealed a complete cohesion between two neighboring islands, resulting in a fine planar structure with minimal coating defects for Ni-W/PPD coatings, authenticating the corrosion parameters.

14.
ACS Omega ; 5(10): 5142-5149, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32201801

RESUMO

Both theory and experiment show that sp2 carbon nanomaterials doped with N have great potential as high-efficiency catalysts for oxygen reduction reactions (ORR). At present, there are theoretical studies that believe that C-sites with positive charge or high-spin density values have higher adsorption capacity, but there are always some counter examples, such as the N-doped graphene nanoribbons with edge defects (ND-GNR) of this paper. In this study, the ORR mechanism of ND-GNR was studied by density functional theory (DFT) calculation, and then the carbon ring resonance energy was analyzed from the perspective of chemical graph theory to elucidate the cause and distribution of active sites in ND-GNR. Finally, it was found that the overpotential of the model can be adjusted by changing the width of the model or dopant atoms while still ensuring proper adsorption energy (between 0.5 and 2.0 eV). The minimum overpotential for these models is approximately 0.36 V. These findings could serve as guidelines for the construction of efficient ORR carbon nanomaterial catalysts.

15.
Beilstein J Nanotechnol ; 11: 407-416, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32215227

RESUMO

Photocatalysis is considered to be a green and promising technology for transforming organic contaminants into nontoxic products. In this work, a CuO/tourmaline composite with zero-dimensional/two-dimensional (0D/2D) CuO architecture was successfully obtained via a facile hydrothermal process, and its photocatalytic activity was evaluated by the degradation of methylene blue (MB). Surface element valence state and molecular vibration characterization revealed that CuO chemically interacted with tourmaline via Si-O-Cu bonds. The specific surface area of the CuO/tourmaline composite (23.60 m2 g-1) was larger than that of the pristine CuO sample (3.41 m2 g-1). The CuO/tourmaline composite exhibited excellent photocatalytic activity for the degradation of MB, which was ascribed to the increase in the quantity of the adsorption-photoreactive sites and the efficient utilization of the photoinduced charge carriers. This study provides a facile strategy for the construction of 0D/2D CuO structures and the design of tourmaline-based functional composite photocatalysts for the treatment of organic contaminants in water.

16.
J Colloid Interface Sci ; 568: 54-62, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32078938

RESUMO

Various experimental investigation had proved that metal dimers possess excellent oxygen reduction reaction (ORR) activity compared to single metal atom catalysts, due to the synergistic effect exerted by two metal atoms. However, it is still unclear how the electrocatalytic activity is enhanced in a fundamental aspect. In this study, we systematically investigated five 3d transition metals (Fe, Co, Ni, Cu and Zn) by density functional theory (DFT) to explore the ability of metal dimers to catalyze the ORR. It is found that different combinations of different metal atoms have different adsorption strengths to oxygenated intermediates, which helps to screen suitable catalyst materials. The scaling relationship of the free energy of adsorption of oxygen-containing species was calculated for various metal-dimer systems. The classical volcanic diagram is derived, and it is found that the CoZnOH embedded nitrogen-doped graphene (the overpotential is 0.61 V) shows the best catalytic properties, and it is predicted that when the adsorption free energy of OH is equal to 0.95 eV, the optimal overpotential is 0.29 V. Electronic structure calculations show that the pairing of different metal atoms alters the d-band center which in turn change the adsorption properties and hence ORR catalytic performance.

17.
RSC Adv ; 10(46): 27856-27863, 2020 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35516928

RESUMO

The CO oxidation mechanisms over three different MnN2-doped graphene (MnN2C2: MnN2C2-hex, MnN2C2-opp, MnN2C2-pen) structures were investigated through first-principles calculations. The vacancy in graphene can strongly stabilize Mn atoms and make them positively charged, which promotes O2 activation and weakens CO adsorption. Hence, CO oxidation activity is enhanced and the catalyst is prevented from being poisoned. CO oxidation reaction (COOR) on MnN2C2 along the Eley-Rideal (ER) mechanism and the Langmuir-Hinshelwood (LH) mechanism will leave one O atom on the Mn atom, which is difficult to react with isolated CO. COOR on MnN2C2-opp along the ER mechanism and termolecular Eley-Rideal (TER) mechanism need overcome low energy barriers in the rate limiting step (RLS), which are 0.544 and 0.342 eV, respectively. The oxidation of CO along TER mechanism on MnN2C2-opp is the best reaction pathway with smallest energy barrier. Therefore, the MnN2C2-opp is an efficient catalysis and this study has a guiding role in designing effective catalyst for CO oxidation.

18.
Materials (Basel) ; 12(16)2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31394836

RESUMO

The effects of second phases on microstructure, microhardness, and corrosion behavior of aged Mg-3Sn (T3) and Mg-3Sn-1Ca (TX31) alloys are investigated systematically. The thermal stability of the CaMgSn phase is higher than that of the Mg2Sn phase, and the microstructure remains essentially unchanged in the TX31 alloy after solution treatment for 28 h at 733 K. The T3 alloy exhibits double age-hardening peaks; one is 54.9 ± 2.1 HV for 7 h, and the other is 57.4 ± 2.8 HV for 15 h. However, the microhardness quickly reaches a stable value with increasing aging times in the TX31 alloy due to the no change in CaMgSn phases. It was also found by electrochemical impedance spectra that the corrosion resistance of aged T3 alloy is superior to that of aged TX31 alloy, especially T3 alloy aged for 7 h. The corrosion film of aged T3 alloy is denser, which attributes to most of dissolved Sn in the α-Mg matrix and the formation of a small quantity of tiny Mg2Sn particles, and effectively prevents the occurrence of further corrosion of the Mg matrix. However, galvanic cells formed between α-Mg and CaMgSn phases accelerate the corrosion of aged TX31 alloy.

19.
Front Chem ; 7: 274, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31069218

RESUMO

The fast consumption of fossil energy accompanied by the ever-worsening environment urge the development of a clean and novel energy storage system. As one of the most promising candidates, the supercapacitor owns unique advantages, and numerous electrodes materials have been exploited. Hence, biomass-derived porous carbon materials (BDPCs), at low cost, abundant and sustainable, with adjustable dimension, superb electrical conductivity, satisfactory specific surface area (SSA) and superior electrochemical stability have been attracting intense attention and highly trusted to be a capable candidate for supercapacitors. This review will highlight the recent lab-scale methods for preparing BDPCs, and analyze their effects on BDPCs' microstructure, electrical conductivity, chemical composition and electrochemical properties. Future research trends in this field also will be provided.

20.
Chem Commun (Camb) ; 55(3): 271-285, 2019 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-30418439

RESUMO

Pillararenes, as a new type of macrocyclic hosts, possess columnar structures and electron-rich cavities. Pillararenes not only recognize suitable cations, but also bind many neutral molecules. Due to the easy modification of pillararenes, various functional groups can be conveniently attached to the rim of pillararenes to provide suitable interaction sites, and the modified pillararenes even bind anionic guests. Thus, pillararenes and their derivatives have presented intriguing and unique host-guest recognition nature in the past few years, which make them ideal building blocks for the preparation of supramolecular polymers. Pillararene-based supramolecular polymers (PSPs) not only possess many merits of traditional covalent polymers but also have many specific properties, such as self-reparability, degradability, and self-adaptation. This feature paper gives an overview of the preparation of PSPs and covers recent research advance and future trends of pillararene-based host-guest pairs, assembly methods, topological architectures, stimuli-responsiveness, and functional features. We expect that the review will be helpful to researchers working in the fields of supramolecular chemistry and polymer science.

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