A facile solvothermal approach was used to prepare brookite-type TiO 2 nanocrystals with different phase content and structure, accomplished by adjusting the ratio of TiCl 4 to t -BuOH. The obtained biphasic brookite/...
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A facile solvothermal approach was used to prepare brookite-type TiO 2 nanocrystals with different phase content and structure, accomplished by adjusting the ratio of TiCl 4 to t -BuOH. The obtained biphasic brookite/rutile TiO 2 nanocrystals showed a high brookite weight content (72%). The photocatalytic degradation of phenol under UV-irradiation was used to determine the synergetic effect from the combination of different phases ( e.g. , brookite, anatase, and rutile). The biphasic NST-4 composed of brookite and rutile exhibited the highest degradation rates, with rate constants three times higher than commercial Degussa P-25. Detailed analysis found that, besides phase composition and content, the semi-embedded structure was essential to obtain a superior activity of biphasic TiO 2 samples.
Skin-like robust materials with prominent sensing performance have potential applications in flexible bioelectronics. However, it remains challenging to achieve mutually exclusive properties simultaneously including l...
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Skin-like robust materials with prominent sensing performance have potential applications in flexible bioelectronics. However, it remains challenging to achieve mutually exclusive properties simultaneously including low interfacial impedance, high stretchability, sensitivity, and electrical resilience. Herein, a material and structure design concept of mixed ion-electron conduction and mechanical interlocking structure is adopted to fabricate high-performance mechanical-bioelectrical dual-modal composites with large stretchability, excellent mechanoelectrical stability, low interfacial impedance, and good biocompatibility. Flower-like conductive metal-organic frameworks (cMOFs) with enhanced conductivity through the overlapped level of metal-ligand orbital are assembled, which bridge carbon nanotubes (denoted as cMOFs-b-CNTs). Then, precursor of poly(styrene-block-butadiene-block-styrene)/ionic liquid penetrates the pores and cavities in cMOFs-b-CNTs-based network fabricated via filtration process, creating a semi-embedded structure via mechanical interlocking. Thus, the mixed ion-electron conduction and semi-embedded structure endow the as-prepared composites with a low interfacial impedance (51.60/28.90 k Omega at 10/100 Hz), wide sensing range (473%), high sensitivity (2195.29), rapid response/recovery time (60/85 ms), low limit of detection (0.05%), and excellent durability (>5000 cycles to 50% strain). Demonstrations of multifunctional mechanical-bioelectrical dual-modal sensors for in vivo/vitro monitoring physiological motions, electrophysiological activities, and urinary bladder activities validate the possibility for practical uses in biomedical research areas. This concept creates opportunities for the construction of durable skin-like sensing materials.
The elaborate spatial arrangement and immobilization of highly active electrocatalysts inside porous substrates are crucial for vanadium redox flow batteries capable of high-rate charging/discharging and stable operat...
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The elaborate spatial arrangement and immobilization of highly active electrocatalysts inside porous substrates are crucial for vanadium redox flow batteries capable of high-rate charging/discharging and stable operation. Herein, a type of bismuth nanosphere/carbon felt is devised and fabricated via the carbothermic reduction of nanostructured bismuth oxides. The bismuth nanospheres with sizes of approximate to 25 nm are distributed on carbon fiber surfaces in a highly dispersed manner and its density reaches up to approximate to 500 pcs mu m(-2), providing abundant active sites. Besides, a unique bismuth nanosphere semi-embedded carbon fiber structure with strong interfacial Bi-C chemical bonding is spontaneously formed during carbothermic reactions, offering an excellent mechanical stability under flowing electrolytes. It shows that the bismuth nanosphere semi-embedded carbon felt can effectively promote V(II)/V(III) redox reactions with appreciable catalytic activity. The battery with the present electrode sustains an energy efficiency of 77.1 +/- 0.2% and an electrolyte utilization of 57.2 +/- 0.2% even when a current density up to 480 mA cm(-2)is applied, which are remarkably higher than those of batteries with the bismuth nanoparticle/carbon felt synthesized by the electrodeposition method (62.6 +/- 0.1%, 23.6 +/- 0.2%). Further, the battery with the present electrode demonstrates a stable energy efficiency retention of 98.2% after 1000 cycles.
For catalytic system consists of Pd as active component and CeO2-ZrO2/Al2O3 (CZ/A) as support, the dispersion and oxidation state of Pd species, which are crucial to the catalytic performance, are closely related to t...
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For catalytic system consists of Pd as active component and CeO2-ZrO2/Al2O3 (CZ/A) as support, the dispersion and oxidation state of Pd species, which are crucial to the catalytic performance, are closely related to the metal-support interaction. In this work, Pd species were introduced into CZ/A system at different thermal treating stages of the support, which brought about different Pd-CZ interaction. The characterization results reveal that when CZ/A support was thermal treated at 300 degrees C prior to the introduction of Pd species, a special Pd/CZ/A catalyst with Pd species semi-embedded in CZ/A was acquired, which exhibits excellent thermal stability owing to the appropriate Pd-CZ interaction. During thermal aging process, encapsulation and aggregation of Pd species are effectively inhibited for Pd/CZ/A with semiembeddedstructure. Thus, higher dispersion, more oxidative Pd2+ species and larger amount of oxygen vacancies are maintained after aging, which consequently lead to its superior three-way catalytic performance. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
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