ABSTRACT
Graphitic carbon nitride (g-C3N4), with facile synthesis, unique structure, high stability, and low cost, has been the hotspot in the field of photocatalysis. However, the photocatalytic performance of g-C3N4 is still unsatisfactory due to insufficient capture of visible light, low surface area, poor electronic conductivity, and fast recombination of photogenerated electron-hole pairs. Thus, different modification strategies have been developed to improve its performance. In this review, the properties and preparation methods of g-C3N4 are systematically introduced, and various modification approaches, including morphology control, elemental doping, heterojunction construction, and modification with nanomaterials, are discussed. Moreover, photocatalytic applications in energy and environmental sustainability are summarized, such as hydrogen generation, CO2 reduction, and degradation of contaminants in recent years. Finally, concluding remarks and perspectives on the challenges, and suggestions for exploiting g-C3N4-based photocatalysts are presented. This review will deepen the understanding of the state of the art of g-C3N4, including the fabrication, modification, and application in energy and environmental sustainability.
Subject(s)
Light , CatalysisABSTRACT
Exploring a scalable strategy to fabricate a multifunctional separator is of great significance to overcome the challenges of lithium polysulfides (LiPSs) and dendritic growth in lithium-sulfur batteries (LSBs). Herein, a binder-free Janus separator is constructed by interfacial engineering. At the cathode interface, an ultra-thin covalent triazine piperazine film containing tailorable micropores and adsorption sites is decorated on polyacrylonitrile (PAN) membrane by in situ interfacial polymerization, building a triple barrier for LiPSs. The combination of steric hindrance and chemical adsorption reduces LiPS's migration by 81.85%. Meanwhile, at the anode interface, a fast-ionic conductor Li6.4 La3 Zr1.4 Ta0.6 O12 (LLZTO) is created on the surface of PAN nanofiber by magnetron sputtering to suppress dendrite growth. Even though there is no binder between the ceramic layer and the fibrous separator, sputtering creates an inter-embedded structure that ensures no depowering after cycling. Furthermore, the PAN-based separator displays a high temperature tolerance of 180 °C. Consequently, the cell delivers a high capacity of 1287.9 mAh g-1 at 0.5 C and stable cycling performance with an ultra-low capacity decay rate of 0.059% per cycle over 500 cycles. This work provides a scalable strategy for functionalizing separators to tackle the challenges in LSBs, which is binder-free, stripping-free, and essentially thickening-free.
ABSTRACT
In this work, porous electrospun polylactic acid (PLA) fibers with high specific surface area and excellent biodegradability were examined as the support of titanium dioxide (TiO2) nanoparticles (NPs). The deposition of TiO2 NPs on porous electrospun PLA fibrous substrates was accomplished through the hydrolysis of titanium tetra isopropoxide (TTIP) under ultrasonic irradiation, and the effects of the TTIP concentrations on structure and property of composite fibers was also investigated. The prepared TiO2-deposited PLA composite fibers were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), High-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET) and thermogravimetric analyzer (TGA). The results indicated that the anatase TiO2 NPs with an average size of about several tens of nanometers to 200 nm were successfully loaded onto surface of porous PLA fibrous substrates. Meanwhile, the TiO2 NPs liked a "double-edged sword," overfull deposition of TiO2 NPs had negative effect on the properties of composite fibers. Under the optimized condition, the TiO2 NPs deposited dispersedly on the surface of PLA fibers without severe agglomeration and this structure performed with a high specific surface area of 64.8 m2/g, which was 5 times as large as pure PLA nanofibers (12.9 m2/g). In addition, the prepared TiO2-loaded composite fibers showed satisfactory removal efficiency on MB, the MB concentration decreased about 75%, which was remarkably higher than that of pure PLA fibers. Compared with powdery TiO2, TiO2-loaded composite fibers showed considerable photocatalytic activity, as well as easier operation, confirming this hybrid composite fibers was suitable for the easier operated application of TiO2.
ABSTRACT
We report a room-temperature ammonia sensor with extra high response values and ideal flexibility, including polyaniline (PANI)-coated titanium dioxide-silicon dioxide (TiO2-SiO2) or copper oxide-titanium dioxide-silicon dioxide (CuO-TiO2-SiO2) composite nanofibers. Such flexible inorganic TiO2-SiO2 and CuO-TiO2-SiO2 composite nanofibers were prepared by electrospinning, followed by calcination. Then, in situ polymerization of aniline monomers was carried out with inorganic TiO2-SiO2 and CuO-TiO2-SiO2 composite nanofibers as templates. Gas sensing tests at room temperature indicated that the obtained CuO-TiO2-SiO2/PANI composite nanofibers had much higher response values to ammonia gas (ca. 45.67-100 ppm) than most of those reported before as well as the prepared TiO2-SiO2/PANI composite nanofibers here. These excellent sensing properties may be due to the P-N, P-P heterojunctions and a structure similar to field-effect transistors formed on the interfaces between PANI, TiO2, and CuO, which is p-type, n-type, and p-type semiconductor, respectively. In addition, the prepared free-standing CuO-TiO2-SiO2/PANI composite nanofiber membrane was easy to handle and possessed ideal flexibility, which is promising for potential applications in wearable sensors in the future.
ABSTRACT
The environmental damage caused by cadmium (Cd) pollution is of increasing concern in China. While the overall plant response to Cd has been investigated in some depth, the contribution (if any) of protein phosphorylation to the detoxification of Cd and the expression of tolerance is uncertain. Here, the molecular basis of the plant response has been explored in hydroponically raised rice seedlings exposed to 10 µΜ and 100 µΜ Cd2+ stress. An analysis of the seedlings' quantitative phosphoproteome identified 2454 phosphosites, associated with 1244 proteins. A total of 482 of these proteins became differentially phosphorylated as a result of exposure to Cd stress; the number of proteins affected in this way was six times greater in the 100 µΜ Cd2+ treatment than in the 10 µΜ treatment. A functional analysis of the differentially phosphorylated proteins implied that a significant number was involved in signaling, in stress tolerance and in the neutralization of reactive oxygen species, while there was also a marked representation of transcription factors.
Subject(s)
Cadmium/toxicity , Oryza/physiology , Phosphoproteins/metabolism , Plant Proteins/metabolism , Seedlings/metabolism , Stress, Physiological , Amino Acid Motifs , Environmental Pollution/adverse effects , Gene Expression Regulation, Plant , Intracellular Space , Oryza/drug effects , Phenotype , Phosphoproteins/chemistry , Phosphoproteins/genetics , Plant Proteins/chemistry , Plant Proteins/genetics , Protein Binding , Protein Interaction Mapping , Protein Interaction Maps , Protein Transport , Proteome , Proteomics/methods , Seedlings/drug effects , Seedlings/geneticsABSTRACT
Camphor sulfonic acid (CSA)-doped polyamide 6/polyaniline (PA6/PANI) composite nanofibers were fabricated using in situ polymerization of aniline under different CSA concentrations (0.02, 0.04, 0.06, 0.08 and 0.10 M) with electrospun PA6 nanofibers as templates. The structural, morphological and ammonia sensing properties of the prepared composite nanofibers were studied using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), four-point probe techniques, X-ray diffraction (XRD) and a home-made gas sensing test system. All the results indicated that the CSA concentration had a great influence on the sensing properties of CSA-doped PA6/PANI composite nanofibers. The composite nanofibers doped with 0.02 M CSA showed the best ammonia sensing properties, with a significant sensitivity toward ammonia (NH3) at room temperature, superior to that of the composite nanofibers doped with 0.04-0.10 mol/L CSA. It was found that for high concentrations of CSA, the number of PANI-H+ reacted with NH3 would not make up a high proportion of all PANI-H+ within certain limits. As a result, within a certain range even though higher CSA-doped PA6/PANI nanofibers had better conductivity, their ammonia sensing performance would degrade.
ABSTRACT
The treatment of catechol via biocatalysis and adsorption with a commercial laccase immobilized on polyacrylonitrile/montmorillonite/graphene oxide (PAN/MMT/GO) composite nanofibers was evaluated with a homemade nanofibrous membrane reactor. The properties in this process of the immobilized laccase on PAN, PAN/MMT as well as PAN/MMT/GO with different weight ratios of MMT and GO were investigated. These membranes were successfully applied for removal of catechol from an aqueous solution. Scanning electron microscope images revealed different morphologies of the enzyme aggregates on different supports. After incorporation of MMT or MMT/GO, the optimum pH showed an alkaline shift to 4, compared to 3.5 for laccase immobilized on pure PAN nanofibers. The optimum temperature was at 55 °C for all the immobilized enzymes. Besides, the addition of GO improved the operational stability and storage stability. A 39% ± 2.23% chemical oxygen demand (COD) removal from the catechol aqueous solution was achieved. Experimental results suggested that laccase, PAN, adsorbent nanoparticles (MMT/GO) can be combined together for catechol treatment in industrial applications.
Subject(s)
Acrylic Resins/chemistry , Biocatalysis , Catechols/chemistry , Enzymes, Immobilized/metabolism , Laccase/metabolism , Membranes, Artificial , Nanofibers/chemistry , Adsorption , Bentonite/chemistry , Enzyme Activation , Enzyme Stability , Enzymes, Immobilized/chemistry , Graphite/chemistry , Hydrogen-Ion Concentration , Laccase/chemistry , Nanofibers/ultrastructure , TemperatureABSTRACT
The TiO2-montmorillonite (TiO2-MMT) complex was prepared by blending TiO2 sol and MMT with certain ratio, and its properties as an enzyme immobilization support were investigated. The pristine MMT and TiO2-MMT calcined at 800 °C (TiO2-MMT800) were used for comparison to better understand the immobilization mechanism. The structures of the pristine MMT, TiO2-MMT, and TiO2-MMT800 were examined by HR-TEM, XRD and BET. SEM was employed to study different morphologies before and after laccase immobilization. Activity and kinetic parameters of the immobilized laccase were also determined. It was found that the TiO2 nanoparticles were successfully introduced into the MMT layer structure, and this intercalation enlarged the "d value" of two adjacent MMT layers and increased the surface area, while the calcination process led to a complete collapse of the MMT layers. SEM results showed that the clays were well coated with adsorbed enzymes. The study of laccase activity revealed that the optimum pH and temperature were pH = 3 and 60 °C, respectively. In addition, the storage stability for the immobilized laccase was satisfactory. The kinetic properties indicated that laccase immobilized on TiO2-MMT complexes had a good affinity to the substrate. It has been proved that TiO2-MMT complex is a good candidate for enzyme immobilization.
Subject(s)
Bentonite/chemistry , Enzymes, Immobilized/metabolism , Laccase/metabolism , Titanium/chemistry , Enzyme Stability , Hydrogen-Ion Concentration , Kinetics , Nanoparticles/chemistry , Nanoparticles/ultrastructure , Temperature , Time FactorsABSTRACT
Breast cancer (BC) is a representative malignant tumor that affects women across the world, and it is the main cause of cancer-related deaths in women. Although a large number of treatment methods have been developed for BC in recent years, the results are sometimes unsatisfying. In recent years, treatments of BC have been expanded with immunotherapy. In our article, we list some tumor markers related to immunotherapy for BC. Moreover, we introduce the existing relatively mature immunotherapy and the markers' pathogenesis are involved. The combination of immunotherapy and other therapies for BC are introduced in detail, including the combination of immunotherapy and chemotherapy, the combined use of immunosuppressants and chemotherapy drugs, immunotherapy and molecular targeted therapy. We summarize the clinical effects of these methods. In addition, this paper also makes a preliminary exploration of the combination of immunotherapy, radiotherapy, and nanotechnology for BC.
ABSTRACT
Polysaccharides are naturally occurring polymers with exceptional biodegradable and biocompatible qualities that are used as hemostatic agents. In this study, photoinduced CC bond network and dynamic bond network binding was used to give polysaccharide-based hydrogels the requisite mechanical strength and tissue adhesion. The designed hydrogel was composed of modified carboxymethyl chitosan (CMCS-MA) and oxidized dextran (OD), and introduced hydrogen bond network through tannic acid (TA) doping. Halloysite nanotubes (HNTs) were also added, and the effects of various doping amount on the performance of the hydrogel were examined, in order to enhance the hemostatic property of hydrogel. Experiments on vitro degradation and swelling demonstrated the strong structural stability of hydrogels. The hydrogel has improved tissue adhesion strength, with a maximum adhesion strength of 157.9 kPa, and demonstrated improved compressive strength, with a maximum compressive strength of 80.9 kPa. Meanwhile, the hydrogel had a low hemolysis rate and had no inhibition on cell proliferation. The created hydrogel exhibited a significant aggregation effect on platelets and a reduced blood clotting index (BCI). Importantly, the hydrogel can quickly adhere to seal the wound and has good hemostatic effect in vivo. Our work successfully prepared a polysaccharide-based bio-adhesive hydrogel dressing with stable structure, appropriate mechanical strength, and good hemostatic properties.
Subject(s)
Hemostatics , Inorganic Chemicals , Humans , Adhesives/pharmacology , Tissue Adhesions , Hydrogels/pharmacology , Hemostasis , Hemostatics/pharmacology , Hemostatics/chemistry , Polysaccharides/pharmacology , Inorganic Chemicals/pharmacologyABSTRACT
Titanium dioxide-polyaniline/polyamide 6 (TiO(2)-PANI/PA6) composite nanofibers were prepared by in situ polymerization of aniline in the presence of PA6 nanofibers and a sputtering-deposition process with a high purity titanium sputtering target. TiO(2)-PANI/PA6 composite nanofibers and PANI/PA6 composite nanofibers were fabricated for ammonia gas sensing. The ammonia sensing behaviors of the sensors were examined at room temperature. All the results indicated that the ammonia sensing property of TiO(2)-PANI/PA6 composite nanofibers was superior to that of PANI/PA6 composite nanofibers. TiO(2)-PANI/PA6 composite nanofibers had good selectivity to ammonia. It was also found that the content of TiO(2) had a great influence on both the morphology and the sensing property of TiO(2)-PANI/PA6 composite nanofibers.
Subject(s)
Ammonia/isolation & purification , Nanofibers/chemistry , Titanium/chemistry , Aniline Compounds , Caprolactam/analogs & derivatives , Caprolactam/chemistry , Gases/chemistry , Polymerization , Polymers/chemistryABSTRACT
High-energy density lithium sulfur battery containing highly active materials is more prone to safety hazards. Besides, the infamous shuttle effect of lithium polysulfides (LiPSs) and listless redox kinetic limit its practical applications. Here, a "one-for-all" design concept for separator enabled by interfacial engineering is proposed to relieve the bottlenecks. For one thing, porous bacterial cellulose (PBC) membrane with high thermostability (no shrinking at 200 °C) and puncture resistance was employed to ensure the battery's safety. For another, a difunctional Ti3C2Tx-SnS2 modified layer could capture LiPSs through lewis-acid interaction and promoted the redox kinetics by catalytically active sites. The symmetric cell with anchoring-electrocatalysis Ti3C2Tx-SnS2-PBC separator infiltrated with the electrolyte delivered an ionic conductivity of 2.171 mS/cm at a high temperature of 180 °C. And a capacity retention is improved by 71.2% compared with PP separator. This work furnishes a facial engineering strategy for manufacturing a multifunctional separator for lithium sulfur batteries.
Subject(s)
Cellulose , Lithium , Cellulose/chemistry , Electric Power Supplies , Lithium/chemistry , Porosity , SulfurABSTRACT
Enzyme membrane systems (EMS) have generated considerable interest because of their advantages of accelerating reactions, eliminating product inhibition, and enhancing conversion rates. However, there are deficiencies in the efficient fabrication of affinity carrier membranes and dynamic catalytic separation properties. Herein, a strong and highly flexible spunlaced viscose/bacterial cellulose (BC) composite membrane in situ embedded with graphene oxide (GO) was developed by combining a scalable bio-synthesis method with atom transfer radical polymerization technology. Notably, the layer-by-layer growth of BC on composite film and the addition of GO resulted in an entangled network with strong hydrogen bonding, endowing the resulting membrane with superior mechanical properties and flexibility, while facilitating a gradient structure and porous transport channels. Subsequently, a novel and highly efficient EMS was constructed by using abundant molecular brushes on composite membrane as immobilized enzyme carrier. The resulting EMS exhibited a high throughput (2.17 L/min*m2) and an interception rate (98.64%) in dynamic catalytic sulfonamide antibiotic wastewater activated with syringaldehyde mediator. Meanwhile, the removal rates of sulphapyridine and sulfamethazine were 97.20% and 94.78% under 0.14 MPa and 15 min, respectively. This efficient and scalable manufacturing strategy is of great significance and may pave a novel pathway for antibiotics wastewater treatment and recycling.
Subject(s)
Anti-Bacterial Agents , Cellulose , Anti-Bacterial Agents/pharmacology , Bacteria , Cellulose/chemistry , Graphite , Porosity , Sulfanilamide , SulfonamidesABSTRACT
Self-disinfecting textile materials employing combined photodynamic/photothermal effects enable the prevention of microbial infections, a property that has great potential in healthcare applications. However, smart textiles with stimulus responses to ambient temperature are marvelous materials for enhancing their photothermal applications with additional functions. It is still challenging to realize vivid and contrasting color changes as temperature indicators. Herein, through the in situ growth of PCN-224 metal-organic frameworks (MOFs), the electrospraying of a Ti3C2 MXene colloid, and the screen printing of a thermochromic dye, a smart photothermochromic self-disinfecting textile has been fabricated. An antibacterial inactivation study revealed 99.9999% inactivation toward gram-negative (Escherichia coli ATCC 8099) and gram-positive (Staphylococcus aureus ATCC 6538) bacteria in 30 min. A mechanism study revealed that light-driven singlet oxygen and heat are the main reasons for bacterial inactivation. Interestingly, the fabrics presented photothermal effects not only under a handheld 780 nm NIR laser but also under visible Xe lamp (λ ≥ 420 nm) illumination. The color of the fabrics (S-CF@PCN0.08) changed completely from dark green to dark red when the temperature exceeded 45 °C under Xe lamp illumination. Furthermore, the photothermochromic effect occurred in just 1 s under a 780 nm laser. Taken together, this smart photothermochromic self-disinfecting textile permits a new way to feedback the timely signal of temperature by color change and provides novel insights into the development of self-disinfecting textiles.
Subject(s)
Anti-Bacterial Agents/chemistry , Coloring Agents/chemistry , Disinfection/methods , Metal-Organic Frameworks/chemistry , Textiles/microbiology , Titanium/chemistry , Anti-Bacterial Agents/pharmacology , Bacterial Infections/prevention & control , Coloring Agents/pharmacology , Escherichia coli/drug effects , Escherichia coli/radiation effects , Hot Temperature , Humans , Light , Metal-Organic Frameworks/pharmacology , Staphylococcus aureus/drug effects , Staphylococcus aureus/radiation effects , Temperature , Titanium/pharmacologyABSTRACT
With the rapid development in wearable electronics, self-powered devices have recently attracted tremendous attention to overcome the restriction of conventional power sources. In this regard, a simple, scalable, and one-pot electrospinning fabrication technique was utilized to construct an all-fiber-structured triboelectric nanogenerator (TENG). Ethyl cellulose was co-electrospun with polyamide 6 to serve as the triboelectric positive material, and a kind of strongly electronegative conductive material of MXene sheet was innovatively incorporated into poly(vinylidene fluoride) nanofiber to act as a triboelectric negative material. The assembled all-fiber TENG exhibited excellent durability and stability, as well as excellent output performance, which reached a peak power density of 290 mW/m2 at a load resistance of 100 MΩ. More importantly, the TENG was capable of harvesting energy to power various light-emitting diodes (LEDs) and monitoring human movements as a self-powered sensor, providing a promising application prospect in wearable electronics.
ABSTRACT
Toward the goal of preventing microbial infections in hospitals or other healthcare institutions, here we developed a self-disinfecting textile with synergistic photodynamic/photothermal antibacterial property. Porphyrinic Metal-organic frameworks (PCN-224) and Ag nanoparticles (NPs) were in situ grown on knitted cotton textile (KCT) successively to achieve rapid photodynamic antibacterial and durable bacteriostatic effect. Light-driven singlet oxygen (1O2) generated from PCN-224 and heat generated from Ag could function synergistically to realize rapid bacterial inactivation. Interestingly, 1O2 could promote Ag NPs to be degraded to release more Ag+ ions, achieving durable bacteriostatic effect. Antibacterial assay demonstrated 6 and 4.49 log unit inactivation toward two typical bacterial strains (E. coli and S. aureus) under Xe arc lamp in 30 min, respectively. Even after ten washes, the textile still maintained 6 log unit bacterial inactivation. Mechanism study proved light-driven 1O2 and heat are main factors causing bacterial inactivation, they could work synergistically to enhance bacterial inactivation efficiency. Photothermal study revealed that the textile could reach to 69 â under visible light and 79.1 â under 780-nm light-laser, which showed much potential in photothermal material applications. Taken together, our findings demonstrated a synergistic self-disinfecting cotton textile that exhibited constructive significance for preventing microbial infections and transmissions.
Subject(s)
Metal Nanoparticles , Staphylococcus aureus , Anti-Bacterial Agents/pharmacology , Escherichia coli , Silver , TextilesABSTRACT
Mineral malnutrition as a prevalent public health issue can be alleviated by increasing the intake of dietary minerals from major staple crops, such as rice. Identification of the gene responsible for mineral contents in rice would help breed cultivars enriched with minerals through marker-assisted selection. Two segregating populations of backcross inbred lines (BIL) were employed to map quantitative trait loci (QTLs) for macronutrient contents in brown and milled rice, BC1F5, and BC2F4:5 derived from an interspecific cross of Xieqingzao B (Oryza sativa) and Dongxiang wild rice (O. rufipogon). Phenotyping the populations was conducted in multiple locations and years, and up to 169 DNA markers were used for the genotyping. A total of 17 QTLs for P, K, Na, Ca, and Mg contents in brown and milled rice distributed on eight regions were identified in the BC1F5 population, which is explained to range from 5.98% to 56.80% of phenotypic variances. Two regions controlling qCa1.1 and qCa4.1 were validated, and seven new QTLs for Ca and Mg contents were identified in the BC2F4:5 population. 18 of 24 QTLs were clustered across seven chromosomal regions, indicating that different mineral accumulation might be involved in common regulatory pathways. Of 24 QTLs identified in two populations, 16 having favorable alleles were derived from O. rufipogon and 10 were novel. These results will not only help understand the molecular mechanism of macronutrient accumulation in rice but also provide candidate QTLs for further gene cloning and grain nutrient improvement through QTL pyramiding.
Subject(s)
Nutrients/metabolism , Oryza/genetics , Oryza/metabolism , Quantitative Trait Loci , Species Specificity , Alleles , Calcium/metabolism , Chromosome Mapping , Chromosomes/ultrastructure , Chromosomes, Plant , Cloning, Molecular , Crosses, Genetic , DNA, Plant/genetics , Genetic Markers , Magnesium/metabolism , Phenotype , Phosphorus/metabolism , Plant Breeding , Polymorphism, Genetic , Potassium/metabolism , Sodium/metabolismABSTRACT
Cadmium is a toxic environmental pollutant that is readily absorbed by rice grains and poses serious threats to human health. The selection and breeding of rice varieties with low cadmium accumulation is one of the most economical and ecological methods to reduce cadmium exposure. In this study, two different indica rice grains under cadmium stress were subjected to mass spectrometry-based metabolomics analysis for the first time. When the cadmium concentration increased in rice grains, most carbohydrates and amino acids were down-regulated, except myoinositol that can prevent cadmium toxicity, which was up-regulated. d-Mannitol and l-cysteine were up-regulated with the increase of cadmium concentration in low-cadmium-accumulating rice. Also, organic acids were activated especially 13-(S)-hydroperoxy-9(Z),11(E),15(Z)-octadecatrienoicacid that is related to the alpha-linolenic acid metabolism and jasmonic acid production. The determination of biomarkers and characterization of metabolic pathways might be helpful for the selection of rice varieties with low cadmium accumulation.
Subject(s)
Cadmium/toxicity , Oryza/drug effects , Oryza/metabolism , Soil Pollutants/toxicity , Amino Acids/metabolism , Biomarkers/analysis , Biomarkers/metabolism , Cadmium/pharmacokinetics , Carbohydrate Metabolism/drug effects , Cyclopentanes/metabolism , Gas Chromatography-Mass Spectrometry , Linolenic Acids/metabolism , Lipid Peroxides/metabolism , Mannitol/metabolism , Mass Spectrometry , Metabolomics/methods , Oryza/chemistry , Oxylipins/metabolism , Plant Structures/chemistry , Soil Pollutants/pharmacokineticsABSTRACT
The practical application of shape-stable phase change composites (PCCs) is beneficial to thermal energy management and energy conservation due to their superior properties. A shape-stable PCC was fabricated by incorporating poly(ethylene glycol) (PEG) with biomass-based porous carbon that was produced via freeze-drying and carbonization using a low-cost and environmentally friendly fresh towel gourd. The towel gourd derived porous carbon with the characteristics of porosity, unique three-dimensional (3D) lamellar structure, and high specific surface area allowed a high encapsulation capacity (up to 94.5 wt %) for PEG. Structural morphologies, as well as the properties of latent heat storage, thermal reliability, thermal energy management, and thermal protection ability of the fabricated shape-stable PCC, were investigated. The micromorphologies revealed that PEG molecular chains were arranged in a 3D lamellar tissue structure. The shape-stable PCC demonstrated excellent thermal reliability and a high melting latent heat of â¼164.3 J/g. The analysis of infrared thermal images indicated that the shape-stable PCC exhibited remarkable strengths in thermal energy management. The result of the thermal insulation simulation experiment proved that the shape-stable PCC had superior thermal protection ability. This study provided an innovative strategy for the design and development of shape-stable PCCs for great potential in heat-insulating protective textiles, solar thermal energy storage, energy-saving buildings, and infrared stealth of military targets.
ABSTRACT
Selecting high-efficiency electrocatalysts of non-noble metals is significant for large-scale industrial applications of electrochemical water splitting. Currently, the synthesis of bimetal alloy nanoparticles is an ideal strategy to improve catalytic efficiency by optimizing adsorption energy and increasing the electrical conductivity of the catalysts. In this work, we report the successful synthesis of FeNi alloy nanoparticle embedded porous nitrogen-doped carbon fibers by a facile electrospinning and carbonizing technology. The effects of different carbonization temperatures on the structure of FeNi alloy nanoparticles in carbon fibers and the electrocatalytic properties were also investigated. The as-prepared composite of carbon fibers and FeNi alloy nanoparticles exhibited a small overpotential of 317 mV at 10 mA cm-2 and low Tafel slope of 49 mV dec-1 for oxygen evolution reaction, as well as good stability. The performance of the novel 1D composite material along with its low-cost and simple-preparation merits is suggestive of great potential for water splitting.