Carbon nanotubes (CNTs) are of great interest for many potential applications because of their extraordinary electronic, mechanical and structural properties. However, issues of chaotic staking, high ...cost and high energy dissipation in the synthesis of CNTs remain to be resolved. Here we develop a facile, general and high-yield strategy for the oriented formation of CNTs from metal–organic frameworks (MOFs) through a low-temperature (as low as 430 °C) pyrolysis process. The selected MOF crystals act as a single precursor for both nanocatalysts and carbon sources. The key to the formation of CNTs is obtaining small nanocatalysts with high activity during the pyrolysis process. This method is successfully extended to obtain various oriented CNT-assembled architectures by modulating the corresponding MOFs, which further homogeneously incorporate heteroatoms into the CNTs. Specifically, nitrogen-doped CNT-assembled hollow structures exhibit excellent performances in both energy conversion and storage. On the basis of experimental analyses and density functional theory simulations, these superior performances are attributed to synergistic effects between ideal components and multilevel structures. Additionally, the appropriate graphitic N doping and the confined metal nanoparticles in CNTs both increase the densities of states near the Fermi level and reduce the work function, hence efficiently enhancing its oxygen reduction activity. The viable synthetic strategy and proposed mechanism will stimulate the rapid development of CNTs in frontier fields.
In real-world Multiple Attribute Decision Making (MADM) problem, the attribute weights information may be unknown or partially known. Several approaches have been suggested to address this kind of ...incomplete MADM problem. However, these approaches depend on the determination of attribute weights, and setting different attribute weight vectors may result in different ranking positions of alternatives. To deal with this issue, this paper develops a novel MADM approach: the ranking range based MADM approach. In the novel MADM approach, the minimum and maximum ranking positions of every alternative are generated using several optimization models, and the average ranking position of every alternative is produced applying the Monte Carlo simulation method. Then, the minimum, maximum and average ranking positions of the alternative are integrated into a new ranking position of the alternative. This novel approach is capable of dealing with venture investment evaluation problems. However, in the venture investment evaluation process, decision makers will present different risk attitudes. To deal with this issue, two ranking range based MADM approaches with risk attitudes are further designed. A case study and a simulation experiment are presented to show the validity of the proposal.
Transition-metal oxides （TMOs） have gradually attracted attention from resear- chers as anode materials for lithium-ion batteries （LIBs） and sodium-ion batteries （SIBs） because of their high ...theoretical capacity. However, their poor cycling stability and inferior rate capability resulting from the large volume variation during the lithiation/sodiation process and their low intrinsic electronic con- ductivity limit their applications. To solve the problems of TMOs, carbon-based metal-oxide composites with complex structures derived from metal-organic frameworks （MOFs） have emerged as promising electrode materials for LIBs and SIBs. In this study, we adopted a facile interface-modulated method to synthesize yolk-shell carbon-based Co3O4 dodecahedrons derived from ZIF-67 zeolitic imida- zolate frameworks. This strategy is based on the interface separation between the ZIF-67 core and the carbon-based shell during the pyrolysis process. The unique yolk-shell structure effectively accommodates the volume expansion during lithiation or sodiation, and the carbon matrix improves the electrical conductivity of the electrode. As an anode for LIBs, the yolk-shell Co3O4/C dodecahedrons exhibit a high specific capacity and excellent cycling stability （1,100 mAh.g-1 after 120 cycles at 200 mA-g-1）. As an anode for S1Bs, the composites exhibit an outstand- ing rate capability （307 mAh-g-1 at 1,000 mA-g-1 and 269 mAh.g-1 at 2,000 mA-g-1）. Detailed electrochemical kinetic analysis indicates that the energy storage for Li＋ and Na＋ in yolk-sheU Co3O4/C dodecahedrons shows a dominant capacitive behavior. This work introduces an effective approach for fabricating carbon- based metal-oxide composites by using MOFs as ideal precursors and as electrode materials to enhance the electrochemical performance of LIBs and SIBs.
Tin dioxide (SnO2) has attracted much attention in lithium‐ion batteries (LIBs) due to its abundant source, low cost, and high theoretical capacity. However, the large volume variation, irreversible ...conversion reaction limit its further practical application in next‐generation LIBs. Here, a novel solvent‐free approach to construct uniform metal–organic framework (MOF) shell‐derived carbon confined SnO2/Co (SnO2/Co@C) nanocubes via a two‐step heat treatment is developed. In particular, MOF‐coated CoSnO3 hollow nanocubes are for the first time synthesized as the intermediate product by an extremely simple thermal solid‐phase reaction, which is further developed as a general strategy to successfully obtain other uniform MOF‐coated metal oxides. The as‐synthesized SnO2/Co@C nanocubes, when tested as LIB anodes, exhibit a highly reversible discharge capacity of 800 mAh g−1 after 100 cycles at 200 mA g−1 and excellent cycling stability with a retained capacity of 400 mAh g−1 after 1800 cycles at 5 A g−1. The experimental analyses demonstrate that these excellent performances are mainly ascribed to the delicate structure and a synergistic effect between Co and SnO2. This facile synthetic approach will greatly contribute to the development of functional metal oxide‐based and MOF‐assisted nanostructures in many frontier applications.
A facile solvent‐free method is developed to synthesize uniform carbon‐confined SnO2/Co nanocubes, which exhibit excellent anodic performance in lithium‐ion batteries owing to the delicately constructed nanostructure. An introduced new conception to obtain uniform metal–organic framework (MOF) shells for metal oxides will greatly promote the development of high‐efficiency electrodes and the application of MOFs in energy storage.
Naturally abundant transition metal oxides with high theoretical capacity have attracted more attention than commercial graphite for use as anodes in lithium-ion batteries. Lithium-ion battery ...electrodes that exhibit excellent electrochemical performance can be efficiently achieved via three-dimensional （3D） architectures decorated with conductive polymers and carbon. As such, we developed 3D carbon-supported amorphous vanadium oxide microspheres and crystalline V203 microspheres via a facile solvothermal method. Both samples were assembled with ultrathin nanosheets, which consisted of uniformly distributed vanadium oxides and carbon. The formation processes were clearly revealed through a series of time-dependent experiments. These microspheres have numerous active reaction sites, high electronic conductivity, and excellent structural stability, which are all far superior to those of other lithium-ion battery anodes. More importantly, 95% of the second-cycle discharge capacity was retained after the amorphous microspheres were subjected to 7,000 cycles at a high rate of 2,000 mA/g. The crystalline microspheres also exhibited a high-rate and long-life performance, as evidenced by a 98% retention of the second-cycle discharge capacity after 9,000 cycles at a rate of 2,000 mA/g. Therefore, this facile solvothermal method as well as unique carbon-supported and nanosheet-assembled microspheres have significant potential for the synthesis of and use in, respectively, lithium-ion batteries.
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•Riboflavin was encapsulated in HIU-HHP combined treated SPI cold gel.•HIU-HHP combination enhanced mechanical property and structural stability of gel.•Stronger gel network improved ...encapsulation and chemical stability of riboflavin.•HIU and HHP synergistically promoted controlled release of riboflavin by gel.•Protein structure change during digestion led to higher riboflavin bioaccessibility.
Transglutaminase (TGase) was added to soy protein isolate (SPI) dispersion after the combination treatment of high intensity ultrasound (HIU) and high hydrostatic pressure (HHP) to catalyze the formation of cold gel, which was used to encapsulate riboflavin. The structure, physicochemical properties and in vitro digestion characteristics of riboflavin-loaded SPI cold gel were investigated. HIU-HHP combined treatment enhanced the strength, water retention, elastic property, thermal stability and protein denaturation degree of riboflavin-loaded SPI cold gels, and improved the gel network structure, resulting in a higher encapsulation efficiency of riboflavin and its chemical stability under heat and light treatment. HIU-HHP combined treatment reduced the erosion and swelling of SPI cold gel in simulated gastrointestinal fluid, and improved the sustained release effect of SPI gel on riboflavin by changing the digestion mode and rate of gel. In addition, HIU-HHP combined treated gels promoted the directional release of riboflavin in the simulated intestinal fluid, thereby improving its bioaccessibility, which was related to the secondary structure orderliness, tertiary conformation tightness and aggregation degree of protein during the gastrointestinal digestion. Therefore, HIU-HHP combined treatment technology had potential application value in improving the protection, sustained/controlled release and delivery of SPI cold gels for sensitive bioactive compounds.
The shortage of oil resources is currently a global problem. The use of renewable resources instead of non-renewable ones has become a hot topic of research in the eyes of scientists. In the food ...industry, there is a lot of interest in bio-based smart active packaging that meets the concept of sustainability and ensures safety. The packaging has antibacterial and antioxidant properties that extend the shelf life of food. Its ability to monitor the freshness of food in real time is also beneficial to consumers’ judgement of food safety. This paper summarises the main raw materials for the preparation of bio-based smart active packaging, including proteins, polysaccharides and composite materials. The current status of the preparation method of bio-based smart active packaging and its application in food preservation is summarised. The future development trend in the field of food packaging is foreseen, so as to provide a reference for the improvement of bio-based smart active packaging materials.
The crosstalk between the nerve and stomatognathic systems plays a more important role in organismal health than previously appreciated with the presence of emerging concept of the "brain-oral axis". ...A deeper understanding of the intricate interaction between the nervous system and the stomatognathic system is warranted, considering their significant developmental homology and anatomical proximity, and the more complex innervation of the jawbone compared to other skeletons. In this review, we provide an in-depth look at studies concerning neurodevelopment, craniofacial development, and congenital anomalies that occur when the two systems develop abnormally. It summarizes the cross-regulation between nerves and jawbones and the effects of various states of the jawbone on intrabony nerve distribution. Diseases closely related to both the nervous system and the stomatognathic system are divided into craniofacial diseases caused by neurological illnesses, and neurological diseases caused by an aberrant stomatognathic system. The two-way relationships between common diseases, such as periodontitis and neurodegenerative disorders, and depression and oral diseases were also discussed. This review provides valuable insights into novel strategies for neuro-skeletal tissue engineering and early prevention and treatment of orofacial and neurological diseases.
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