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Showing papers on "Chemical binding published in 2017"


Journal ArticleDOI
TL;DR: In this paper, a self-template synthesis of metallic and polar Co 9 S 8 nanocrystals inlaid carbon hollow nanopolyhedra as an efficient sulfur host material is reported.

291 citations


Journal ArticleDOI
TL;DR: In this article, a high-performance lithium-sulfur battery with sandwich-structured characteristic is synthesized for highperformance Li2S battery, where sulfur is impregnated in nitrogen-doped graphene and constructed as primary active material, which is further welded in the carbon nanotube/nanofibrillated cellulose (CNT/NFC) framework.
Abstract: Freestanding cathode materials with sandwich-structured characteristic are synthesized for high-performance lithium–sulfur battery. Sulfur is impregnated in nitrogen-doped graphene and constructed as primary active material, which is further welded in the carbon nanotube/nanofibrillated cellulose (CNT/NFC) framework. Interconnected CNT/NFC layers on both sides of active layer are uniquely synthesized to entrap polysulfide species and supply efficient electron transport. The 3D composite network creates a hierarchical architecture with outstanding electrical and mechanical properties. Synergistic effects generated from physical and chemical interaction could effectively alleviate the dissolution and shuttling of the polysulfide ions. Theoretical calculations reveal the hydroxyl functionization exhibits a strong chemical binding with the discharge product (i.e., Li2S). Electrochemical measurements suggest that the rationally designed structure endows the electrode with high specific capacity and excellent rate performance. Specifically, the electrode with high areal sulfur loading of 8.1 mg cm−2 exhibits an areal capacity of ≈8 mA h cm−2 and an ultralow capacity fading of 0.067% per cycle over 1000 discharge/charge cycles at C/2 rate, while the average coulombic efficiency is around 97.3%, indicating good electrochemical reversibility. This novel and low-cost fabrication procedure is readily scalable and provides a promising avenue for potential industrial applications.

155 citations


Journal ArticleDOI
TL;DR: In this paper, a facile, scalable, and green process to fabricate porous graphene (PG) modified separators for commercially viable lithium-sulfur batteries was reported, in combination with an amphiphilic polymer binder, rendered the engineered functional layer with extraordinary electrical conductivity, high surface area, large pore volume, and appropriate strength of chemisorption to polysulfides.

150 citations


Journal ArticleDOI
TL;DR: The approach demonstrates the potential of regulating lithium-sulfur battery performances at a molecular scale promoted by the porous organic polymers with a flexible design.
Abstract: Lithium–sulfur battery represents a promising class of energy storage technology owing to its high theoretical energy density and low cost. However, the insulating nature, shuttling of soluble polysulfides and volumetric expansion of sulfur electrodes seriously give rise to the rapid capacity fading and low utilization. In this work, these issues are significantly alleviated by both physically and chemically restricting sulfur species in fluorinated porous triazine-based frameworks (FCTF-S). One-step trimerization of perfluorinated aromatic nitrile monomers with elemental sulfur allows the simultaneous formation of fluorinated triazine-based frameworks, covalent attachment of sulfur and its homogeneous distribution within the pores. The incorporation of electronegative fluorine in frameworks provides a strong anchoring effect to suppress the dissolution and accelerate the conversion of polysulfides. Together with covalent chemical binding and physical nanopore-confinement effects, the FCTF-S demonstrates ...

149 citations


Journal ArticleDOI
01 Oct 2017-Small
TL;DR: The strong chemical binding interaction between the polysulfides and TiO2 feather duster efficiently restrains the shuttle effect, leading to enhanced electrochemical kinetics and the novel CC/TiO2 /S composite cathode exhibits a high capacity.
Abstract: The rechargeable lithium-sulfur battery is recognized as a promising candidate for electrochemical energy storage system because of their exceptional advance in energy density. However, the fast capacity decay of sulfur cathode caused by polysulfide dissolution and low specific capacity caused by poor electrical conductivity still impede the further development of lithium-sulfur battery. To address above issues, this study reports the synthesis of feather duster-like TiO2 architecture by in situ growth of TiO2 nanowires on carbon cloth and further evaluates as sulfur host material. The strong chemical binding interaction between the polysulfides and TiO2 feather duster efficiently restrains the shuttle effect, leading to enhanced electrochemical kinetics. Besides, the in situ grown TiO2 NWs array also supply high surface for sulfur-loading and fast path for electron transfer and ion diffusion. As results, the novel CC/TiO2 /S composite cathode exhibits a high capacity of 608 mA h g-1 at 1.0 C after 700 cycles corresponding to capacity decay as low as 0.045% per cycle with excellent Coulombic efficiency higher than 99.5%.

141 citations


Journal ArticleDOI
TL;DR: In this article, multifunctional Ti4O7 particles with interconnected-pore structure are designed and synthesized using porous poly(styrene-b-2-vinylpyridine) particles as a template.
Abstract: Multifunctional Ti4O7 particles with interconnected-pore structure are designed and synthesized using porous poly(styrene-b-2-vinylpyridine) particles as a template. The particles can work efficiently as a sulfur-host material for lithium–sulfur batteries. Specifically, the well-defined porous Ti4O7 particles exhibit interconnected pores in the interior and have a high-surface area of 592 m2 g−1; this shows the advantage of mesopores for encapsulating of sulfur and provides a polar surface for chemical binding with polysulfides to suppress their dissolution. Moreover, in order to improve the conductivity of the electrode, a thin layer of carbon is coated on the Ti4O7 surface without destroying its porous structure. The porous Ti4O7 and carbon-coated Ti4O7 particles show significantly improved electrochemical performances as cathode materials for Li–S batteries as compared with those of TiO2 particles.

128 citations


Journal ArticleDOI
TL;DR: In this article, a hierarchical porous carbon (NPHP) composite with a high sulfur content of 73% was used as a host for Li-S batteries, which not only benefits from the synergistic effect of structural confinement (physisorption) and chemical binding (chemisorption), but also provides high capacity (1580m 2 ǫg −1 at 002C) and long lifetime (200 cycles with 71% retention) for LiS batteries.

125 citations


Journal ArticleDOI
TL;DR: Partial least squares regression analysis showed that perfluoroalkyl carboxylic acids (PFCAs) were related to latitude according to their perfluorocarbon chain length, with longer chains associated with higher latitudes, suggesting the presence of mechanisms promoting higher prevalence of longer chained PFCAs in the north.

79 citations


Journal ArticleDOI
05 Oct 2017-ACS Nano
TL;DR: Findings point to the tremendous potential of sp3 defects in development of room temperature quantum light sources capable of operating at telecommunication wavelengths as the emission of the defect states can readily be extended to this range via use of larger diameter SWCNTs.
Abstract: Aiming to unravel the relationship between chemical configuration and electronic structure of sp3 defects of aryl-functionalized (6,5) single-walled carbon nanotubes (SWCNTs), we perform low-temperature single nanotube photoluminescence (PL) spectroscopy studies and correlate our observations with quantum chemistry simulations. We observe sharp emission peaks from individual defect sites that are spread over an extremely broad, 1000–1350 nm, spectral range. Our simulations allow us to attribute this spectral diversity to the occurrence of six chemically and energetically distinct defect states resulting from topological variation in the chemical binding configuration of the monovalent aryl groups. Both PL emission efficiency and spectral line width of the defect states are strongly influenced by the local dielectric environment. Wrapping the SWCNT with a polyfluorene polymer provides the best isolation from the environment and yields the brightest emission with near-resolution limited spectral line width ...

76 citations


Journal ArticleDOI
TL;DR: In this paper, the removal efficiency and mechanism of four typical ARGs with two different molecular structures (i.e., cyclic (c)- and double-stranded (ds)- by graphene oxide (GO) nanosheet were systematically investigated.

75 citations


Journal ArticleDOI
Li Shiqi1, Juliusz Warzywoda1, Shu Wang1, Guofeng Ren1, Zhaoyang Fan1 
01 Nov 2017-Carbon
TL;DR: In this article, a crosslinked carbon nanofiber aerogel (CNFA) with extremely low density, attained from pyrolysis of bacterial cellulose (BC) aerogels, was studied for sulfur cathodes.

Journal ArticleDOI
TL;DR: In this article, density functional theory calculations were carried out to study the adsorption and sensing properties of Fe-doped graphene nanosheets (FeG) toward nitrogen oxides (NO, NO2, and N2O).

Journal ArticleDOI
TL;DR: In this paper, the Fenton activity of mesoporous iron oxide was firstly extended to pH of 3.6-10.0 by the carbon quantum dots and Cu modification (CQDs/Cu-MIO), and the optimum reaction condition was evaluated and the degradation process of OFX was further investigated by FT-IR spectrum.

Journal ArticleDOI
TL;DR: In this article, a bi-functional additive of triphenyl borate (TPB) was proposed to improve the safety and electrochemical performance of Ni-rich cathode materials.

Journal ArticleDOI
Yingbin Tan1, Zhiqing Jia1, Peili Lou1, Zhonghui Cui1, Xiangxin Guo1 
TL;DR: In this article, a self-assembly sandwich composed of zeolitic-imidazolate-frameworks (ZIF-8)-derived mesoporous carbons is presented.

Journal ArticleDOI
TL;DR: In this article, a facile strategy is reported for synthesizing ionic liquid supramolecules (ILSMs) as well as Pt-based alloys on the carbon black surface in a room temperature ionic fluid (trifluoromethylsulfonyl) imide) under one atmospheric pressure plasma.
Abstract: A facile strategy is reported for synthesizing ionic liquid supramolecules (ILSMs) as well as Pt-based alloys on the carbon black surface in a room temperature ionic liquid (1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide) under one atmospheric pressure plasma. The bimetallic PtNi-nanoparticles (NPs) with a size of 2.5–3 nm are stably and uniformly hybridized on the surface of the carbon black, which is covered with a layer of ILSMs. The formation of the developed catalyst is examined using TEM, HAADF-STEM, XRD, TEM-EDS, and TGA measurements. The obtained catalyst exhibits high oxygen reduction reaction (ORR) activity, which is better than those of commercial Pt/C catalysts and Pt/C catalysts prepared without using ionic liquids. This strategy has been extended to fabricate trimetallic PtNiRu-NPs/C nanohybrids with further enhanced activities of up to 2.26 mAcm −2 and 1.31 Amg Pt −1 at 0.9 V versus RHE. The trimetallic PtNiRu-NPs/C catalyst is also more stable than the commercial product under ORR conditions due to the chemical binding of the alloys with the carbon black and the physical stabilization of the nanohybrid materials through the conductive protecting layer of the ILSMs. The results prove that the developed catalysts push the ORR toward completion and can be a promising candidate for numerous electrocatalytic applications.

Journal ArticleDOI
TL;DR: The S/ONPC composite exhibits a high utilization of sulfur and good electrochemical performance via the immobilization of the polysulfides through strong chemical binding, and in battery testing, the sulfur/oxygen and nitrogen co-doped porous carbon composite materials reveal a high initial capacity.
Abstract: In this work, a facile strategy to synthesize oxygen and nitrogen co-doped porous carbon (ONPC) is reported by one-step pyrolysis of waste coffee grounds. As-prepared ONPC possesses highly rich micro/mesopores as well as abundant oxygen and nitrogen co-doping, which is applied to sulfur hosts as lithium/sulfur batteries' appropriate cathodes. In battery testing, the sulfur/oxygen and nitrogen co-doped porous carbon (S/ONPC) composite materials reveal a high initial capacity of 1150 mAh·g-1 as well as a reversible capacity of 613 mAh·g-1 after the 100th cycle at 0.2 C. Furthermore, when current density increases to 1 C, a discharge capacity of 331 mAh·g-1 is still attainable. Due to the hierarchical porous framework and oxygen/nitrogen co-doping, the S/ONPC composite exhibits a high utilization of sulfur and good electrochemical performance via the immobilization of the polysulfides through strong chemical binding.

Journal ArticleDOI
TL;DR: In this paper, a hierarchical-porous Graphene/C/SiO 2 hollow microspheres were designed as scaffold to load sulfur, which could leave enough room for volume changes of sulfur during the charge-discharge process, and imprison the polysulfide via physical adsorption and chemical binding.

Journal ArticleDOI
TL;DR: In this paper, a multi-cavity, walnut-like carbon sphere (GO-MCWCS) cathode was proposed to solve the problem of insufficient cycle stability of Li-S batteries.

Journal ArticleDOI
TL;DR: In this article, the authors developed a novel confinement approach by using porous hollow carbon nanospheres (HCNs) embedded with well-dispersed cobalt monoxide (CoO) nanocrystals, which can effectively combine the advantages of physical entrapment and chemical binding interactions of sulfur species.
Abstract: Lithium–sulfur (Li–S) batteries are promising energy storage systems owing to their high theoretical energy density and low costs due to the abundant reserves of sulfur. However, the easy dissolution of intermediate polysulfides (Li2Sx, 4 < x ≤ 8) and insulating nature of sulfur have hindered their commercialization. Herein, we develop a novel confinement approach by using porous hollow carbon nanospheres (HCNs) embedded with well-dispersed cobalt monoxide (CoO) nanocrystals (CoO/HCN), which can effectively combine the advantages of physical entrapment and chemical binding interactions of sulfur species. When used as a sulfur host material, the CoO/HCN–S composite cathode with 1.4 mg cm−2 sulfur exhibits excellent electrochemical performance with high discharge capacity (996 mA h g−1 after 200 cycles at 0.2C), great rate capability (620 mA h g−1 at 5.0C) and superior cycle stability (629 mA h g−1 after 1000 cycles at 1.0C with a capacity decay of only 0.033% per cycle and 482 mA h g−1 after 1000 cycles at 2.0C with a capacity decay of only 0.043% per cycle). Furthermore, a high and stable reversible capacity of 640 mA h g−1 after cycling for 250 cycles is achieved with a higher sulfur mass loading (3.6 mg cm−2).

Journal ArticleDOI
F.P. Yu1, Yilin Li1, Meng Jia1, Tian Nan1, He Zhang1, Shiqiang Zhao1, Qiang Shen1 
TL;DR: In this paper, a framework of macro-/micro-porous carbon derived from commercial lignin is prepared by one-step carbonization/activation method and then utilized as sulfurloading matrix to assay the effect of sulfurloading time on the structural and electrochemical properties of carbon-sulfur composite (C-S-t, t defined as sulfur-loading time).

Journal ArticleDOI
01 Jan 2017-Small
TL;DR: An organic thin-film gas sensor based on squaraine detects ammonia as low as 40 ppb with impressive reversibility and stability and the embedded squaric ring makes SA-CH3 highly sensitive.
Abstract: An organic thin-film gas sensor based on squaraine detects ammonia as low as 40 ppb with impressive reversibility and stability. The resonance-stabilized zwitterionic characteristics offer squaraines high affinity and sensitivity toward electron-rich analytes without irreversible chemical binding, while the embedded squaric ring makes SA-CH3 highly sensitive. The symmetric molecular geometry and good crystallinity also contribute to the high performance.

Patent
03 Jul 2017
TL;DR: An optical biomodule for detecting a disease specific biomarker(s), utilizing enhanced fluorescence emission (due to integration of a three-dimensional (3-D) protruded structure (s)) in a fluidic container/zero-mode waveguide, upon chemical binding of a disease-specific biomarker with its corresponding specific disease specific binder(s) (e.g., an aptamer(s)) is disclosed as discussed by the authors.
Abstract: An optical biomodule for detecting a disease specific biomarker(s), utilizing enhanced fluorescence emission (due to integration of a three-dimensional (3-D) protruded structure (s)) in a fluidic container/zero-mode waveguide, upon chemical binding of a disease specific biomarker(s) with its corresponding specific disease specific biomarker binder(s) (e.g., an aptamer(s)) is disclosed. Additionally, chemical compositions and targeted, passive and programmable/active delivery (in near real-time/real-time) of bioactive compounds and/or bioactive molecules for lowering the risks of Alzheimer's, Cardiovascular and Type-2 Diabetes diseases are disclosed.

Journal ArticleDOI
TL;DR: The data suggest that binding type between As and Fe oxide should be considered when determining the bioaccessibility of As in soil, which, in turn, greatly influences the realistic risk of As present in soil.

Journal ArticleDOI
TL;DR: In this article, two different additives are tested, based on Al, Mg and Ca. The results from the characterization techniques TGA, AAS, IC, and XRD show that the formation of particulate matter during a complete thermo-chemical conversion can be suppressed to certain extend.
Abstract: The combustion of solid biofuels is characterized by the formation of particulate matter emissions harmful to humans and the environment. Inorganic elements which are volatile under high temperatures (∼600–1200 °C) are emitted as vapor, then cooling down in the flue gas, and are re-sublimated and emitted as solid particulate matter emissions (fly ash). Thus, the objective of this paper is it to summarize the current knowledge of the forming mechanism of these particulate matter emissions taking place during the combustion of wood and straw, and bring the elements in particulate matter with the help of additive in a stable solid phase, so they stay in the bottom ash and are not emitted. Here, two different additives are tested, based on Al, Mg and Ca. Important in this respect is the knowledge of the chemical formations during the combustion process of the different ash-forming elements contained within solid biofuels. Therefore, the chemical binding forms of the ash-forming elements (Si, Al, Fe, Ca, Mg, Mn, Na, K, P, S, and Cl) within the solid biofuel are presented. Based on this, possible conversion products are discussed including theoretical calculated intermediates; this includes the chemical conversion pathway. On this basis, additives are identified based on the difference of the elemental composition of wood/straw blends to wood and the results of the formation of particulate matter during combustion are assessed in lab scale. The additives are composed of Al2O3, CaHPO4, and CaCO3 or Al2O3, MgHPO4, and MgCO3. The results from the characterization techniques TGA, AAS, IC, and XRD show that the formation of particulate matter during a complete thermo-chemical conversion can be suppressed to certain extend.

Journal ArticleDOI
TL;DR: This study integrates QSAR, docking, and systems biology approaches as a virtual screening tool for use in risk assessment and presents a computational systems biology approach using carbaryl as a case study.

Journal ArticleDOI
TL;DR: A simple chemical route is utilized to decorate ZnO nanoparticles (NP) on the coral-like Cu2O nanowires (NW) surface as a p-n heterojunction photocathode for photoelectrochemical (PEC) hydrogen production as discussed by the authors.

Book ChapterDOI
01 Jan 2017
TL;DR: The “smart” multifunctional nanostructures should work as customizable, targeted drug-delivery vehicles capable of carrying large doses of therapeutic agents into malignant cells.
Abstract: The development of various nanotechnologies have provided a new field of research, which allows the manipulation of molecular components of matter and covers a vast array of nanodevices. The “smart” multifunctional nanostructures should work as customizable, targeted drug-delivery vehicles capable of carrying large doses of therapeutic agents into malignant cells. Some nanomedical approaches are based on the use of functionalized nanoparticles (NPs), not only to reduce toxicity and side effects of drugs but, also in potential the biological barriers crossing on, such as: the blood–brain barrier, different cellular compartments, including the nucleus. Currently, many materials are used for nanoparticle preparation, several of biological derivation, such as albumin, gelatin, phospholipids, etc.; others of chemical nature, such as various polymers, hydrogels, solid metals. Covalent and noncovalent chemical linking using different molecules have been reported for NPs surface functionalization, confer them specific properties, such as targeting ability. Based on the strategy chosen to control release (pH or redox or temperature sensitive NPs), different drugs are linked to NPs by adsorption, incorporation, or chemical binding. Use of smart nanocarriers can be a successful approach to overcome the limits of drug delivery.

Journal ArticleDOI
TL;DR: Doxorubicin-loaded multifunctional polymeric micelles are also introduced to alleviate MDR of DOX, in which polymers act as MDR modulators.
Abstract: Doxorubicin (DOX), as an anthracycline, plays an important role in chemotherapy. But multidrug resistance (MDR) tremendously retards the anticancer effect of DOX and results in the failure of chemotherapy. Multifunctional micelles emerge as a valid strategy to load DOX by physical encapsulation or chemical binding to be delivered to cancer cells against MDR. In this review, mechanism of MDR of DOX is simply described. Multifunctional co-delivery micelles of DOX and main MDR modulators have been summarised in detail. DOX-loaded multifunctional polymeric micelles are also introduced to alleviate MDR of DOX, in which polymers act as MDR modulators.

Journal ArticleDOI
TL;DR: The synergistic effect of MnO2 nanostructure and N-doped carbon nanospheres for enhanced performance of lithium-sulfur battery cathodes is demonstrated.
Abstract: In this work, nitrogen-doped hollow porous carbon nanospheres coated with MnO2 nanosheets (NHPC@MnO2) were prepared as a novel sulfur host for the cathode of lithium-sulfur battery. N-doping of carbon and deposition of the inherently polar MnO2 promote chemical binding of the host with sulfur and its reduction products, known as polysulfides. Meanwhile, proper N-doping can improve the electron conductivity of carbon, and the nanosheet structure may help to guarantee facile electron- and lithium-ion transport through MnO2. Attributed to these advantages, the NHPC@MnO2/S cathode with a high sulfur content (70 wt% and 2.6 mg cm-2) exhibited an excellent cycle stability: its capacity retention was 93% within 100 cycles at 0.5 C. It also displayed a good rate capability: discharge capacities being ∼1130 mAh g-1 at 0.2 C, ∼1000 mAh g-1 at 0.5 C, ∼820 mAh g-1 at 1 C, and ∼630 mAh g-1 at 2 C. Our work demonstrates the synergistic effect of MnO2 nanostructure and N-doped carbon nanospheres for enhanced performance of lithium-sulfur battery cathodes.