| 1. |
- Ye, Yin, et al.
(författare)
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Removal and recovery of aqueous U(VI) by heterogeneous photocatalysis: Progress and challenges
- 2022
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 450
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Forskningsöversikt (refereegranskat)abstract
- With the rapidly expanding implementations of nuclear power technology, the contamination of the aquatic environment by uranium is a rising environmental problem. Photocatalytic reduction of hexavalent uranium (U(VI)) is a plausible solution to the aqueous uranium contamination, which has generated increasing research interest in the recent decade. Therefore, a systematic assessment highlighting the important direction for future studies is in need. We herein present a critical review to address the following two aspects: (1) the progress and current understandings of photocatalytic U(VI) removal technology, including various applied catalysts, current understanding of the kinetics and mechanisms, the effects of key operation parameters, and the effects of co-existing water constituents; (2) key knowledge gaps that need future research efforts in this field.
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| 2. |
- Feng, Yi, et al.
(författare)
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Flexible UHF resistive humidity sensors based on carbon nanotubes
- 2012
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Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 12:9, s. 2844-2850
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the investigation of the resistive humidity-sensing properties of multi-walled carbon nanotubes (MWCNTs). MWCNTs functionalized by acid treatment (f-MWCNTs) exhibit rather high sensitivity in resistance toward humidity, owing to the presence of carboxylic groups on the nanotube surface. By integrating the f-MWCNTs resistor into a wireless sensor platform, flexible humidity sensors for ultra-high frequency applications are investigated. The operating frequency range of the sensor is dramatically increased from 600 MHz to 2 GHz by adjusting the resistor-electrodes' configuration. This enhancement is predominately attributed to the variation in parasitic capacitance between the resistor-electrodes.
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| 3. |
- Wang, Baoyuan, et al.
(författare)
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Fast ionic conduction in semiconductor CeO2-delta electrolyte fuel cells
- 2019
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Ingår i: NPG ASIA MATERIALS. - : Nature Publishing Group. - 1884-4049 .- 1884-4057. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Producing electrolytes with high ionic conductivity has been a critical challenge in the progressive development of solid oxide fuel cells (SOFCs) for practical applications. The conventional methodology uses the ion doping method to develop electrolyte materials, e.g., samarium-doped ceria (SDC) and yttrium-stabilized zirconia (YSZ), but challenges remain. In the present work, we introduce a logical design of non-stoichiometric CeO2-delta based on non-doped ceria with a focus on the surface properties of the particles. The CeO2-delta reached an ionic conductivity of 0.1 S/cm and was used as the electrolyte in a fuel cell, resulting in a remarkable power output of 660 mW/cm(2) at 550 degrees C. Scanning transmission electron microscopy (STEM) combined with electron energy-loss spectroscopy (EELS) clearly clarified that a surface buried layer on the order of a few nanometers was composed of Ce3+ on ceria particles to form a CeO2-delta@CeO2 core-shell heterostructure. The oxygen deficient layer on the surface provided ionic transport pathways. Simultaneously, band energy alignment is proposed to address the short circuiting issue. This work provides a simple and feasible methodology beyond common structural (bulk) doping to produce sufficient ionic conductivity. This work also demonstrates a new approach to progress from material fundamentals to an advanced low-temperature SOFC technology.
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