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Lithium dendrites are easily generated for excessively-solved lithium ions (Li+) inside the lithium metal batteries, which will lead serious safety issues. In this experiment, carbon spheres (CS) are successfully anchored on TiO2 (CS@TiO2) in the hydrothermal polymerization, which is filtrated on the commercial PE separator (CS@TiO2@PE). The negative charge in CS can suppress random diffusion of anions through electrostatic interactions. Density functional theory (DFT) calculations show that CS contributes to the desolvation of Li+, thereby increasing the migration rate of Li+. Furthermore, TiO2 exhibits high affinity to liquid electrolytes and acts as a physical barrier to lithium dendrite formation. CS@TiO2 is a combination of the advantages of CS and TiO2. As results, the Li+ transference number of the CS@TiO2@PE separator can be promoted to 0.63. The Li||Li cell with the CS@TiO2@PE separator exhibits a stable cycle performance for more than 600 h and lower polarization voltage (17 mV) at 1 mA cm-2. The coulombic efficiency (CE) of the Li||Cu cells employe the CS@TiO2@PE separator is 81.63% over 130 cycles. The discharge capacity of LiFePO4||Li cells based on the CS@TiO2@PE separator is 1.73 mAh (capacity retention = 91.53% after 260 cycles). Thus, the CS@TiO2 layer inhibits lithium dendrite formation.
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Photoreforming is a clean photocatalytic technology for simultaneous plastic waste degradation and hydrogen fuel production, but there are still limited active and stable catalysts for this process. This work introduces the brookite polymorph of TiO2 as an active photocatalyst for photoreforming with an activity higher than anatase and rutile polymorphs for both hydrogen production and plastic degradation. Commercial brookite successfully converts polyethylene terephthalate (PET) plastic to acetic acid under light. The high activity of brookite is attributed to good charge separation, slow decay and moderate electron trap energy, which lead to a higher generation of hydrogen and hydroxyl radicals and accordingly enhanced photo-oxidation of PET plastic. These results introduce brookite as a stable and active catalyst for the photoconversion of water contaminated with microplastics to value-added organic compounds and hydrogen.
Assuntos
Ácido Acético , Plásticos , Titânio/química , HidrogênioRESUMO
The power conversion efficiency (PCE) of a dye-sensitized solar cell (DSSC) device depends on its semiconductor characteristics. Titanium dioxide (TiO2) nanoparticles are a semiconductor material commonly used in the DSSC device whose characteristics depend on the synthesis process. There are many routes to synthesize TiO2, however, they typically involve hazardous approaches, which may cause risk to the environment. Green synthesis is an environmentally friendly alternative method using ecological solvents that eliminates toxic waste and reduces energy consumption. In this work, tropical almond (Terminalia catappa L.) was used as a natural capping agent in the green synthesis to control the growth of TiO2. In addition, graphene oxide (GO) was used as a dopant to increase the performance of DSSC device. The results are convincing, in which the addition of 0.0017 % GO doping in tropical almond extract mediated green synthesis of TiO2 improved the PCE from 0.85 % to 1.72 %. These results suggest that GO-modified TiO2 nanoparticles green synthesized using tropical almond extract have great potential in the fabrication of DSSC devices with good PCE, low cost, and low environmental impact.
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The inclusion of particles in a polymeric substrate to achieve certain properties is a well-known practice. In the case of textile substrates, this practice may deeply affect the structure of the produced yarns, as even a filament with no textile applications can be obtained. In this manuscript, titanium dioxide (TiO2) particles were incorporated into polyester (PET) chips and the influence of these fillers on the properties of yarn and fabric, and the ultraviolet protection factor (UPF) was assessed. For this purpose, rutile and anatase crystalline forms of TiO2, as well as the size of the particles, were evaluated. Moreover, parameters such as mechanical properties, orientation of the macromolecules and thermal behavior were analyzed to ensure that the textile grade is maintained throughout the production process. The results showed that the inclusion of micro- and nanoparticles of TiO2 decreases the molecular weight and tenacity of PET. Also, although orientation and crystallinity varied during the textile process, the resulting heatset fabrics did not present important differences in those parameters. Finally, the attainment of textile-grade PET-TiO2 fabrics with UPF indexes of 50+ with both rutile and anatase and micro- and nano-sized TiO2 forms was demonstrated.
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Laser-induced graphene (LIG) is a promising material for various applications due to its unique properties and facile fabrication. However, the electrochemical performance of LIG is significantly lower than that of pure graphene, limiting its practical use. Theoretically, integrating other conductive materials with LIG can enhance its performance. In this study, we investigated the effects of incorporating gold nanoparticles (AuNPs) and titanium dioxide (TiO2) into LIG on its electrochemical properties using ReaxFF molecular dynamics (MD) simulations and experimental validation. We found that both AuNPs and TiO2 improved the work function and surface potential of LIG, resulting in a remarkable increase in output voltage by up to 970.5% and output power density by 630% compared to that of pristine LIG. We demonstrated the practical utility of these performance-enhanced LIG by developing motion monitoring devices, self-powered sensing systems, and robotic hand platforms. Our work provides new insights into the design and optimization of LIG-based devices for wearable electronics and smart robotics, contributing to the advancement of sustainable technologies.
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Objective To prepare titanium dioxide (TiO2 ) nanoparticles with good near-infrared light and study the loading and release of doxorubicin. Methods The Sm doped TiO2 nanoparticles (Sm-TiO2 ) were synthesized using a modified solvothermal reaction and then observed with transmission electron microscope. The fluorescence spectrum, doxorubicin loading capacity and release profile were also determined. Results The obtained Sm-TiO2 nanoparticles with the length from 100-200 nm were fusiform and well dispersed. The emission wavelength was 640-670 nm. The drug loading capacity in water was 11. 5% . DOX in vitro was pH sensitive to release. Conclusion Sm-TiO2 nanoparticles have good near-infrared light, high drug loading capacity and controllable drug release are obtained and should be studied further more as a novel carrier.
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Statement of problem. Proliferation of Candida albicans is primarily within the plaque on the fitting surface of the denture rather than on the inflamed mucosa. Consequently, the treatment of the denture is equally important as treatment of the tissue. Cleansing and disinfection should be efficiently carried-out as the organisms can penetrate into the voids of the acrylic resin and grow in them, from which they can continue to infect and reinfect bearing tissues. Purpose. The purpose of this study was to evaluate the applicability of photocatalytic reaction to eliminate Candida albicans from acrylic resin denture base, and to investigate the antifungal effect with various UVA illumination time. Materials and Methods. The specimens were cured by the conventional method following the manufacturer's instruction using thermal polymerized denture base resin (Vertex RS; Dentimex, Netherlands). TiO2 photocatalyst sol(LT), which is able to be coated at normal temperature, was made from the Ti-alkoxide progenitor. The XRD patterns, TEM images and nitrogen absorption ability of the TiO2 photocatalyst sol(LT) were compared with the commercial TiO2 photocatalyst P-25. The experimental specimens were coated with the mixture of the TiO2 photocatalyst sol(LT) and binder material (silane) using dip-coater, and uncoated resin plates were used as the control group. Crystallinity of TiO2 of the specimen was tested by the XRD. Size, shape and chemical compositions were also analyzed using the FE-SEM/EDS. The angle and methylene blue degradation efficiency were measured for evaluating the photocatalytic activity of the TiO2 film. Finally, the antifungal activity of the specimen was tested. Candida albicans KCTC 7629(1 ml, initial concentration 105cells/ml) were applied to the experiment and control group specimens and subsequently two UVA light source with 10W, 353 nm peak emission were illuminated to the specimens from 15cm above. The extracted 2 microliter of sample was plated on nutrient agar plate (BactoTM Brain Heart Infusion; BD, USA) with 10 minute intervals for 120 minute, respectively. It was incubated for 24 hours at 37 degree C and the colony forming units (CFUs) were then counted. Results. Compared the characteristics of LT photocatalyst with commercial P-25 photocatalyst, LT were shown higher activity than P-25. The LT coated experimental specimen surface had anatase crystal form, less than 20 nm of particle size and wide specific surface area. To evaluate the photocatalytic activity of specimens, methylene blue degradation reaction were used and about 5% of degradation rate were measured after 2 hours. The average contact angle was less than 20.indicating that the LT photocatalyst had hydrophilicity. In the antifungal activity test for Candida albicans, 0% survival rate were measured within 30 minute after irradiation of UVA light. Conclusion. From the results reported above, it is concluded that the UVA-LT photocatalytic reaction have an antifungal effect on the denture surface Candida albicans, and so that could be applicable to the clinical use as a cleaning method.