Multiple Synergistic Effects Research Articles

Lantern-like bismuth oxyiodide embedded typha-based carbon via in situ self-template and ion exchange-recrystallization for high-performance photocatalysis.

Efficient photocatalysts induced by visible light (e.g. BiOI) have attracted wide attention for energy storage and environmental pollutant rehabilitation. In this work, N-doped bamboo tube-like carbon (NTC) was derived directly from the carbonization of bio-waste (withered typha grass) under an ammonia atmosphere. During fabrication, the BiOI/NTC material was used as a self-sacrificing template and I- ions were gradually replaced by OH- ions from NH3·H2O solution. Then Bi7O9I3/NTC was formed with micro-/nanohierarchical structures, which could exactly be explained by the in situ ion exchange-recrystallization mechanism. Thereinto, the well-defined hierarchical lantern-like Bi7O9I3 composed of interconnecting ultrathin nanosheets firmly embedded the "bamboo tubes" of NTC, which endow sufficient interface and high specific surface area (40 m2 g-1). The multiple synergistic effects of the lantern-like structure with ultrathin nanosheets, low iodine content and well-contacted interface endow the synthesized Bi7O9I3/NTC with outstanding visible-light catalytic activity. The results show that the obtained Bi7O9I3/NTC degraded 93.5% of methyl orange and 97.6% of rhodamine B within 2 hours, showing superior performance as compared to the pure BiOI. Therefore, our work demonstrates a controllable approach that can provide guidelines for designing optimized bismuth oxyiodide-based photocatalyst materials and has the potential for application in environmental remediation.

3D carbon nanocage networks with multiscale pores for high-rate supercapacitors by flower-like template and in-situ coating

3D hierarchical carbon nanocages, a novel carbon-based material, have demonstrated a strong momentum of high rate capability and power density supercapacitors. Herein we report the preparation of 3D carbon nanocage networks by nano coating carbon precursor on flower-like basic magnesium carbonate microspheres combining with in situ MgO template carbonization and KOH treatment. This material features with interconnected 3D network structure, crosslinked carbon nanocages (15–24nm in size and 2.5–3nm in shell thickness), high specific surface area (1470–1927m2g-1), multiscale pores (macro/meso/micropores) and uniform pore size distribution. Resulting from the multiple synergistic effects of these advantages, the 3D carbon nanocage networks present a remarkably excellent electrochemical performance with a large specific capacitance of 380Fg-1 at 1Ag-1 and high rate capability of 82% when increasing the current density up to 50Ag-1 in three-electrode configuration. For HPCNC-700-a symmetrical supercapacitor, the specific capacitance reaches up to 288Fg-1 at 1Ag-1 and still maintains at 256Fg-1 at 10Ag-1 with the capacitance retention of 89%.

Superior potassium storage in chitin-derived natural nitrogen-doped carbon nanofibers

Potassium ion batteries (KIBs) are drawing intensive attention as the next-generation energy storage technology, owning to their similar electrochemical properties to lithium system and rich abundance of potassium resources. The carbonaceous materials with low cost, nontoxicity and high safety have been considered as promising candidates for KIBs anodes. However, they still suffer from several problems, such as poor cycling and rate capability, complex activation process steps and multiple procedures to import heteroatoms doping. Herein, the N-doped carbon nanofibers (NCFs) are fabricated by direct pyrolysis of bio-waste chitin, which is the second most abundant biopolymer throughout nature. The as-prepared NCFs used as KIBs anodes, without any additional activation steps, are systematically investigated for the first time. They deliver high capacity, excellent rate capability and long-term cycling stability, which benefit from the multiple synergistic effects of suitable interlayer spacing, heteroatom doping and unique one dimensional mesoporous structure. With the spotlight of environmental friendliness, low cost and high energy density in energy storage field, the chitin-based NCFs demonstrate great potential for future low-cost energy storage applications.

Few layer nitrogen-doped graphene with highly reversible potassium storage

Few-layer nitrogen-doped graphene (FLNG) have been successfully prepared by a simple bottom-up synthesis of technique using Dicyandiamide and Coal tar pitch as raw materials. The as-synthesized FLNG with the thickness of about 2–10nm, high surface area (479.21m2g−1) and high nitrogen content (14.68 at%) exhibits excellent K-ion storage performances. The FLNG delivers competitive reversible capacity (320mAhg−1 at 50mAg−1 after 60 cycles), superior rate capability as well as long-term cycling life at large current density (150mAhg−1 at 500mAg−1 after 500 cycles). The multiple synergistic effects of nitrogen doping, high specific surface area, interconnected mesopores with large pore volume not only facilitate the ions transportation throughout the electrode matrix, but also provide substantial active sites for K-ion storage. Furthermore, Electrochemical Impedance Spectroscopy (EIS) of the FLNG electrode during the initial K-ion intercalation process were measured to thoroughly understand the electrochemical reaction process. These results will be beneficial for designing novel anode materials for alkaline-ion batteries in the future.

Micro and nano hierachical structures of BiOI/activated carbon for efficient visible-light-photocatalytic reactions

Constructing the heterojunctions or designing the novel nanostructures are thought as effective methods to improve photocatalytic activities of semiconductors. Herein, a one-step green route was developed to fabricate bismuth oxyiodide/activated carbon (BiOI/C) composite. The prepared BiOI/C exhibit obviously red shifts and increased absorption range of visible light. The presence of Bi-C bonds confirms the heterojunction, on account of which the BiOI nanosheets tightly grew on the surface of carbon and subsequently provided the hierarchical structure, sufficient interfacial interaction and high specific surface area. Significantly, the sufficient interracial interaction is beneficial to the detachment of electrons (e−)-holes (h+) pairs and the Bi-C bonds work like a bridge to rapidly transmit the e− from BiOI to carbon. What’s more, the hierarchical structure of BiOI/C efficiently shortened the diffusion pathways of pollutants and the high SBET provided more exposed reaction sites. Benefiting from multiple synergistic effects, the as-prepared BiOI/C exhibited enhanced photocatalytic activities in degrading Rhodamine B (RhB) solution under visible light irradiation. The degradation rate of optimized BiOI/C reaches up to 95% in 120 min, and the efficiency is 3.36 times higher than pure BiOI. This study provides a promising strategy that activated carbon can be utilized in highly-efficiency photocatalysts.

Nitrogen-Superdoped 3D Graphene Networks for High-Performance Supercapacitors.

An N-superdoped 3D graphene network structure with an N-doping level up to 15.8 at% for high-performance supercapacitor is designed and synthesized, in which the graphene foam with high conductivity acts as skeleton and nested with N-superdoped reduced graphene oxide arogels. This material shows a highly conductive interconnected 3D porous structure (3.33 S cm-1 ), large surface area (583 m2 g-1 ), low internal resistance (0.4 Ω), good wettability, and a great number of active sites. Because of the multiple synergistic effects of these features, the supercapacitors based on this material show a remarkably excellent electrochemical behavior with a high specific capacitance (of up to 380, 332, and 245 F g-1 in alkaline, acidic, and neutral electrolytes measured in three-electrode configuration, respectively, 297 F g-1 in alkaline electrolytes measured in two-electrode configuration), good rate capability, excellent cycling stability (93.5% retention after 4600 cycles), and low internal resistance (0.4 Ω), resulting in high power density with proper high energy density.

KOH direct treatment of kombucha and in situ activation to prepare hierarchical porous carbon for high-performance supercapacitor electrodes

Kombucha, a renewable biomass, has been successfully utilized as an accessible carbon source to fabricate kombucha-derived hierarchical porous carbon (KHPC) by KOH direct treatment and in situ activation. The prepared KHPC shows an interconnected hierarchical porous structure, a pore volume of 0.41 cm3 g−1, and a specific surface area of 917 m2 g−1. Due to the multiple synergistic effects of these advantages, the KHPC-3 exhibits a high specific capacitance of 326 F g−1 at a current density of 1 A g−1 in 6 M KOH, good rate capability of 82% retention from 1 to 20 A g−1, and cycling performance with 91.3% retention over 5000 cycles. Moreover, the KHPC-3 symmetric supercapacitor reveals a good energy density of 20.97 Wh kg−1 at a power density of 871.2 W kg−1 and retains 8.08 Wh kg−1 at 6330 W kg−1 in 1 M Na2SO4 electrolyte. Therefore, the KHPC obtained via the simple synthesis process shows great promise as an electrode material in energy storage devices.

Creating Nitrogen-Doped Hollow Multiyolk@Shell Carbon as High Performance Electrodes for Flow-Through Deionization Capacitors

A novel electrode material for flow-through deionization capacitors consisting of the hollow multiyolk@shell carbon (HMYSC) with effective nitrogen doping has been rationally designed and originally prepared by a template-directed coating method. The HMYSC can be divided into several hollow carbon spheres cores and the nitrogen-doped shell. The as-obtained HMYSC shows many favorable features for flow-through deionization capacitors, such as large specific surface area (910 m2 g–1), hierarchical pores, high conductivity and good wettability. With the multiple synergistic effects of the above features, the as-prepared HMYSC electrode has higher specific capacitance, lower inner resistance and good stability. In the deionization test, the HMYSC electrode exhibits a high salt adsorption capacity of 16.1 mg g–1 under the applied voltages of 1.4 V in a 500 mg L–1 NaCl solution. Furthermore, it has been demonstrated that the HMYSC electrodes presented faster salt adsorption rate under the applied voltages of 0.8...

Fish gill-derived activated carbon for supercapacitor application

Fish gill-derived porous activated carbon (FGAC) has been successfully prepared by simultaneous carbonization and activation. The FGAC composed of cross-linked thin carbon nanosheets reveals large specific surface area, wide-range hierarchical porous structure and appropriate contents of oxygen and nitrogen functional groups. As a supercapacitor electrode material, the FGAC shows high specific capacitance of 334 F g−1 at 2 A g−1 in 6 M KOH, good electrochemical stability and excellent rate capability (only 7% capacitance fading when the current density is increased by 20 times). These attractive electrochemical performances are ascribed to the multiple synergistic effects of the structure and chemistry of the FGAC, which can not only facilitate ion diffusion, transport and adsorption, but also increase surface area for charge accumulation.

Direct Synthesis of Few-Layer F-Doped Graphene Foam and Its Lithium/Potassium Storage Properties.

Heteroatom-doped graphene is considered a potential electrode materials for lithium-ion batteries (LIBs). However, potassium-ion batteries (PIBs) systems are possible alternatives due to the comparatively higher abundance. Here, a practical solid-state method is described for the preparation of few-layer F-doped graphene foam (FFGF) with thickness of about 4 nm and high surface area (874 m(2)g(-1)). As anode material for LIBs, FFGF exhibits 800 mAh·g(-1) after 50 cycles at a current density of 100 mA·g(-1) and 555 mAh·g(-1) after 100 cycles at 200 mA·g(-1) as well as remarkable rate capability. FFGF also shows 165.9 mAh·g(-1) at 500 mA·g(-1) for 200 cycles for PIBs. Research suggests that the multiple synergistic effects of the F-modification, high surface area, and mesoporous membrane structures endow the ions and electrons throughout the electrode matrix with fast transportation as well as offering sufficient active sites for lithium and potassium storage, resulting in excellent electrochemical performance. Furthermore, the insights obtained will be of benefit to the design of reasonable electrode materials for alkali metal ion batteries.

Synthesis of Mesoporous ZnO Nanosheets via Facile Solvothermal Method as the Anode Materials for Lithium-ion Batteries.

Mesoporous ZnO nanosheets are synthesized through a room temperature solvothermal method. Transmission and scanning electronic microscopy observations indicate that as-prepared ZnO hierarchical aggregates are composed and assembled by nanosheets with a length of 1–2 μm and a thickness of 10–20 nm, and interlaced ZnO nanosheets irregularly stack together, forming a three-dimensional network. Furthermore, large mesopores are embedded in the walls of ZnO nanosheets, confirmed by Brunauer-Emmett-Teller (BET) measurement. Accordingly, the resulting ZnO anode exhibits a high and stable specific discharge capacity of 421 mAh g−1 after 100 cycles at 200 mA g−1 and a good rate capability. Such electrochemical performance could be attributed to the multiple synergistic effects of its mesoporous nanosheet structure, which can not only provide a large specific surface area for lithium storage, but also favor the ion transport and electrolyte diffusion.

MgO-templated hierarchical porous carbon sheets derived from coal tar pitch for supercapacitors

Two-dimensional hierarchical porous carbon sheets (FHPCs) have been prepared by using nano-MgO sheet as template and coal tar pitch as carbon precursor coupled with KOH activation. The weight ratio of pitch with potassium hydroxide (KOH) exerts a marked effect on the porosity of the carbon. The FHPCs materials show some advantages for electrochemical energy storage including a specific surface area of 1454∼1604m2g−1, sheet structure, hierarchical porosity with macro/meso/micropores, rich O-doping (19wt%). Resulting from the multiple synergistic effects of these advantages, the FHPC1:2 electrode can achieve a high capacitance of 290Fg−1 and 250Fg−1at 1Ag−1, 20Ag−1, respectively, and excellent rate capability with 86% retention rate in 6M KOH electrolyte. The FHPC1:2 symmetric supercapacitor displays a high energy density of 20.28 Wh kg−1at a power density of 873Wkg−1 and retains as high as 8.87 Wh kg−1at 6389Wkg−1 in 1M Na2SO4 electrolyte. Our work demonstrates that KOH activation coupled with flake-like MgO template can act as an excellent route to prepare hierarchical porous carbon sheets from coal tar pitch for high performance supercapacitors.

Hierarchical porous nitrogen-doped carbon nanosheets derived from silk for ultrahigh-capacity battery anodes and supercapacitors.

Hierarchical porous nitrogen-doped carbon (HPNC) nanosheets (NS) have been prepared via simultaneous activation and graphitization of biomass-derived natural silk. The as-obtained HPNC-NS show favorable features for electrochemical energy storage such as high specific surface area (SBET: 2494 m(2)/g), high volume of hierarchical pores (2.28 cm(3)/g), nanosheet structures, rich N-doping (4.7%), and defects. With respect to the multiple synergistic effects of these features, a lithium-ion battery anode and a two-electrode-based supercapacitor have been prepared. A reversible lithium storage capacity of 1865 mA h/g has been reported, which is the highest for N-doped carbon anode materials to the best of our knowledge. The HPNC-NS supercapacitor's electrode in ionic liquid electrolytes exhibit a capacitance of 242 F/g and energy density of 102 W h/kg (48 W h/L), with high cycling life stability (9% loss after 10,000 cycles). Thus, a high-performance Li-ion battery and supercapacitors were successfully assembled for the same electrode material, which was obtained through a one-step and facile large-scale synthesis route. It is promising for next-generation hybrid energy storage and renewable delivery devices.

Population genetics revisited - towards a multidisciplinary research field

Population genetic research has transformed from the study of genetic structures into a much wider and highly multidisciplinary research field. In this contribution, we outline the limitations of classic population genetic data and highlight the potential of combining molecular data with additional environmental, ecological and biological data sets in multidisciplinary approaches. The combination of data sets from various fields allows a more comprehensive understanding of extrinsic and intrinsic evolutionary processes affecting populations such as the distinction between genetic drift and natural selection. The integration of population size estimates and demographic dynamics as well as individual behaviour (embracing aspects like dispersal behaviour) allows for testing of adaptations to local environments and understanding time-lags frequently observed in molecular data. Modelling approaches are integrated at increasing rates into population genetic research to identify potential barriers and corridors. In our review, we therefore highlight multiple synergistic effects when combining population genetic data with morphological, ecological, behavioural data and modelling. We outline strengths and limitations and indicate future possibilities and challenges. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 115, 1–12.

Multiple synergistic effects of emotion and memory on proactive processes leading to scene recognition

Visual scene recognition is a proactive process through which contextual cues and top-down expectations facilitate the extraction of invariant features. Whether the emotional content of the scenes exerts a reliable influence on these processes or not, however, remains an open question. Here, topographic ERP mapping analysis and a distributed source localization method were used to characterize the electrophysiological correlates of proactive processes leading to scene recognition, as well as the potential modulation of these processes by memory and emotion. On each trial, the content of a complex neutral or emotional scene was progressively revealed, and participants were asked to decide whether this scene had previously been encountered or not (delayed match-to-sample task). Behavioral results showed earlier recognition for old compared to new scenes, as well as delayed recognition for emotional vs. neutral scenes. Electrophysiological results revealed that, ~400ms following stimulus onset, activity in ventral object-selective regions increased linearly as a function of accumulation of perceptual evidence prior to recognition of old scenes. The emotional content of the scenes had an early influence in these areas. By comparison, at the same latency, the processing of new scenes was mostly achieved by dorsal and medial frontal brain areas, including the anterior cingulate cortex and the insula. In the latter region, emotion biased recognition at later stages, likely corresponding to decision making processes. These findings suggest that emotion can operate at distinct and multiple levels during proactive processes leading to scene recognition, depending on the extent of prior encounter with these scenes.

Synergistic Effects of Iridoid Glycosides on the Survival, Development and Immune Response of a Specialist Caterpillar, Junonia coenia (Nymphalidae)

Plants use a diverse mix of defenses against herbivores, including multiple secondary metabolites, which may affect herbivores synergistically. Chemical defenses also can affect natural enemies of herbivores via limiting herbivore populations or by affecting herbivore resistance or susceptibility to these enemies. In this study, we conducted larval feeding experiments to examine the potential synergistic effects of iridoid glycosides (IGs) found in Plantago spp. (Plantaginaceae) on the specialist buckeye caterpillar, Junonia coenia (Nymphalidae). Caterpillars were placed on artificial diets containing different concentrations of single IGs (aucubin or catalpol alone) or combinations of the two IGs. Larval performance and immune response were recorded to test the hypothesis that IGs would have positive synergistic effects on buckeyes, which are specialists on IG plants. The positive synergistic effects that IGs had on buckeyes in our experiments included lower mortality, faster development, and higher total iridoid glycoside sequestration on mixed diets than on aucubin- or catalpol-only diets. Furthermore, we found negative synergistic effects of IGs on the immune response of buckeye caterpillars. These results demonstrate multiple synergistic effects of IGs and indicate a potential trade-off between larval performance and parasitoid resistance.

Evidence of GLP-1-mediated neuroprotection in an animal model of pyridoxine-induced peripheral sensory neuropathy

Pyridoxine (vitamin B6) intoxicated rodents develop a peripheral neuropathy characterized by sensory nerve conduction deficits associated with disturbances of nerve fiber geometry and axonal atrophy. To investigate the possibility that glucagon-like peptide-1 (7–36)-amide (GLP-1) receptor agonism may influence axonal structure and function through neuroprotection neurotrophic support, effects of GLP-1 and its long acting analog, Exendin-4 (Ex4) treatment on pyridoxine-induced peripheral neuropathy were examined in rats using behavioral and morphometric techniques. GLP-1 is an endogenous insulinotropic peptide secreted from the gut in response to the presence of food. GLP-1 receptors (GLP-1R) are coupled to the cAMP second messenger pathway, and are expressed widely throughout neural tissues of humans and rodents. Recent studies have established that GLP-1 and Ex4, have multiple synergistic effects on glucose-dependent insulin secretion pathways of pancreatic β-cells and on neural plasticity. Data reported here suggest that clinically relevant doses of GLP-1 and Ex4 may offer some protection against the sensory peripheral neuropathy induced by pyridoxine. Our findings suggest a potential role for these peptides in the treatment of neuropathies, including that associated with type II diabetes mellitus.

Glucagon like peptide-1: A new therapeutic target for diabetes mellitus

Glucagon-like peptide-1 (GLP-1) is an endogenous peptide secreted from the gut in response to the presence of food. GLP-1 and its longer acting analog exendin-4 have multiple synergistic effects on glucose dependent, insulin secretion pathways of the pancreatic β-cell and on plasticity in neuronal cells. Recently the development of these peptides as a novel therapeutic strategy for non-insulin-dependent (type 2) diabetes mellitus and associated neuropathy has been the focus of much interest. Here we describe the biological actions of GLP-1 and its related analogs.

Book Review on Fire

Book Review on Fire