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Photoswitchable Membranes Based on Peptide‐Modified Nanoporous Anodic Alumina: Toward Smart Membranes for On‐Demand Molecular Transport 下载免费PDF全文
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Mohamed M. Ibrahim Amine Mezni Mohammed Alsawat Tushar Kumeria Manash R. Das Shaykha Alzahly Ali Aldalbahi Karolina Gornicka Jacek Ryl Mohammed A. Amin Tariq Altalhi 《国际能源研究杂志》2019,43(10):5367-5383
In this work, PdO/TiO2 and Eu2O3/TiO2 nanocomposites (NCs) were synthesized using a new facile, template‐free, and one‐step solvothermal approach and characterized by several instrumentation techniques. X‐ray photoelectron spectroscopy studies revealed the presence of oxidized form of the Pd and Eu nanoparticles within the NC materials (PdO and Eu2O3). The two catalysts exhibited remarkable activity for the hydrogen evaluation reaction (HER) in a strong alkaline solution (4.0 M NaOH) with PdO/TiO2 catalyst being the best, which recorded an exchange current density (jo) of 0.26 mA cm?2 and a Tafel slope (βc) of 125 mV dec?1. Such parameters are not far from those recorded for a commercial Pt/C catalyst (0.71 mA cm?2 and 120 mV dec?1) performed here under the same operating conditions. Eu2O3/TiO2 catalyst recorded jo and βc values of 0.05 mA cm?2 and 135 mV dec?1. The Tafel slopes 125 and 135 mV dec?1 calculated on the PdO/TiO2 and Eu2O3/TiO2 catalysts suggest a HER kinetics controlled by the Volmer step. PdO/TiO2 catalyzed the HER with a high turnover frequency of 2.3 H2/s at 0.2 V versus the reversible hydrogen electrode, while Eu2O3/TiO2 catalyst only measured a turnover frequency value of 1.25 H2/s at the same overpotential. The two catalysts exhibited excellent stability and durability after 10 000 cycles and 72 hours of controlled potential electrolysis at a high cathodic overpotential, reflecting their practical applicability. Scanning electron microscope and X‐ray photoelectron spectroscopy examinations revealed that the morphology and chemistry of both catalysts were not altered as a result of the performed long‐term stability and durability tests. 相似文献
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Luminescent Silicon Diatom Replicas: Self‐Reporting and Degradable Drug Carriers with Biologically Derived Shape for Sustained Delivery of Therapeutics 下载免费PDF全文
Shaheer Maher Mohammed Alsawat Tushar Kumeria Dina Fathalla Gihan Fetih Abel Santos Fawzia Habib Dusan Losic 《Advanced functional materials》2015,25(32):5107-5116
Current development of drug microcarriers is mainly based on spherical shapes, which are not biologically favorable geometries for complex interactions with biological systems. Scalable synthesis of drug carriers with nonspherical and anisotropic shapes featuring sustained drug‐releasing performances, biocompatibility, degradability, and sensing capabilities is challenging. These challenges are addressed in this work by employing Nature's optimized designs obtained from low‐cost diatomaceous earth mineral derived from single‐cell algae diatoms. Silica diatoms with unique shapes and 3D microcapsule morphology are converted into silicon diatom replicas with identical structure by a magnesiothermic reduction process. The results reveal that prepared silicon diatoms have a set of unique properties including favorable microcapsule structure with high surface area and micro/mesoporosity providing high drug loading, fast biodegradability, and intrinsic luminescence, which make them highly suitable for low‐cost production of advanced drug microcarriers. Their sustained drug release >30 days combined with self‐reporting function based on silicon luminescence properties using nonluminescent and luminescent drugs for intravitreal drug therapy is successfully demonstrated. These silicon diatoms offer promising potential toward scalable production of low‐cost and advanced microcarriers for broad medical therapies, including theranostics and microrobotic guided drug delivery devices. 相似文献
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Membranes: Photoswitchable Membranes Based on Peptide‐Modified Nanoporous Anodic Alumina: Toward Smart Membranes for On‐Demand Molecular Transport (Adv. Mater. 19/2015) 下载免费PDF全文
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Mezni Amine Ibrahim Mohamed M. Ben Saber Nesrine Alsawat Mohammed Kumeria Tushar Altalhi Tariq 《Journal of Inorganic and Organometallic Polymers and Materials》2021,31(11):4372-4379
Journal of Inorganic and Organometallic Polymers and Materials - In the present study, a modified solvothermal reaction of (hematite) with titanium(IV) butoxide and gold(III) chloride produced... 相似文献
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Microcarriers: Luminescent Silicon Diatom Replicas: Self‐Reporting and Degradable Drug Carriers with Biologically Derived Shape for Sustained Delivery of Therapeutics (Adv. Funct. Mater. 32/2015) 下载免费PDF全文
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Mohamed M. Ibrahim Amine Mezni Mohammed Alsawat Tushar Kumeria Arwa Alrooqi Abdallah A. Shaltout Sameh I. Ahmed Rabah Boukherroub Mohammed A. Amin Tariq Altalhi 《国际能源研究杂志》2020,44(8):6725-6744
A newly synthesized zinc(II) complex, namely tert-butyl N-(2 mercaptoethyl)carbamatozinc(II) complex [Zn(Boc-S)2] (Boc = tert-butyl N-[2-mercaptoethyl]carbamate), has been used as an organozinc precursor for the production of crystalline ZnO and ZnO/TiO2 nanoparticles. The synthesized complex and the obtained nanomaterials were fully characterized using various spectroscopic and surface analysis techniques. Their surface morphology, chemical purity and stoichiometry have been investigated by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) as well as X-ray fluorescence. The synthesized Zn(II) molecular complex, ZnO and ZnO/TiO2 nanomaterials have been tested in alkaline aqueous solution (1.0 MNaOH) for the hydrogen evolution reaction (HER) using various electrochemical techniques. The results revealed high HER catalytic performance of ZnO and ZnO/TiO2 cathode materials, with the latter exhibiting higher catalytic activity recording an exchange current density (jo) of 0.3 mA cm−2. This current value, which approaches that of Pt wire (0.5 mA cm−2), cross-sectional area ~0.008 cm2, is about 11 and 100 times greater than those measured for ZnO alone (0.028 mA cm−2) and TiO2 alone (0.0032 mA cm−2), respectively. Moderate catalytic activity was recorded for the complex catalyst, namely GC-Zn(Boc-S)2 with jo value of (0.01 mA cm−2). Tafel slope values of 130 and 122 mV dec−1 were calculated for ZnO and ZnO/TiO2, respectively. Such Tafel slope values, which are close to that of the Pt wire (120 mV dec−1), referred to a Volmer-controlled HER kinetics. Other important electrochemical parameters describing the kinetics of the HER, such as roughness factor (Rf) and turnover frequency (TOF) were also estimated and discussed. The high numerical values of the various HER kinetic parameters recorded for the ZnO/TiO2 catalyst, in addition to its high stability and durability (stable for up to 10 000 continuous cathodic polarization cycles), besides maintaining its morphology and chemical composition after stability test (confirmed from SEM/EDX and XRD examinations), located it in a privileged position among the most efficient HER electrocatalysts reported in the literature. 相似文献
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