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- 2018
- imgae sensor
- internet of things
- drone
- visible light ID
- Signal-to-Noise Ratio (SNR)
- Infinite Gain Multiple Feedback (IGMF)
- Visible Light Communications (VLC)
- LED
- Trans-Impedance Amplifier (TIA)
- Optoelectronic Information Science and Engineering
- Tohoku University
- University of Northumbria
- University of Huddersfield
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Visible-light photocatalytic fuel cell with Z-scheme g-C3N4/Fe0/TiO2 anode and WO3 cathode efficiently degrades berberine chloride and stably generates electricity
摘要： A visible-light Z-scheme g-C3N4/Fe0/TiO2 anodic catalyst was tested with cathodic WO3 in photocatalytic Fuel Cell (PFC) that efficiently degrades berberine chloride and simultaneously generate electricity at pH 2,5,7 and 13. The Stainless-steel mesh electrodes loaded with prepared catalyst were irradiated by visible-light in single chamber PFC. The highest removal of berberine Chloride, cell voltage, and power density were 91%, 0.8 V, and 16.4 W/m2 at a current density of 2.02 mA/cm2, respectively after 90 min irradiation in 0.05 M Na2SO4 electrolyte, with 10 ? external resistance. The impacts of pH and initial concentration of BEC on photocatalytic degradation and cell voltage were evaluated. The cell current density is enhanced while the photocatalyst activity increased. The constructed PFC maintained high-performance after 5 uses. Its use in degrading wide spectrum refractory pollutants and generate electricity is expected for the proved catalyst design, paired electrodes and high PFC performance for practical wastewater treatment.
关键词： Electricity generation,WO3,Visible-light,g-C3N4/Fe0/TiO2,Photocatalytic Fuel Cell,Berberine Chloride,Z-scheme
更新于2025-09-10 09:29:36
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Enhanced visible light photocatalytic activity of zno nanoparticles modified by cyclized polyacrynitrile
摘要： The ZnO/cyclized polyacrylonitrile (CPAN) composites were prepared by impregnation and heat treatment process. The morphology, crystal internal structure of ZnO/CPAN nanocomposites were characterized by UV-vis-diffuse reflectance spectroscope (DRS), X-ray diffraction, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The visible light photocatalytic activity of ZnO/CPAN was evaluated by degradation of methyl orange under xenon lamp irradiation. The DRS results indicate that the absorption of ZnO/CPAN nanocomposites in the visible region was significantly higher than that of pure ZnO nanoparticles. The TEM results show that the surface of ZnO nanoparticles is occupied by the CPAN in small amount. The results of photocatalytic experiment show that the photocatalytic activity of ZnO nanoparticles can be improved significantly by the modification of CPAN. The possible photocatalytic mechanism was also discussed.
关键词： visible light,photocatalytic activity,nanocomposite,ZnO/CPAN
更新于2025-09-10 09:29:36
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Function-integrated Ru catalyst for photochemical CO2 reduction
摘要： Visible-light driven catalytic reduction of CO2 is at the heart of artificial photosynthesis. Here, we demonstrate the first example of a Ru complex that can function both as a photosensitizer and catalyst for CO2 reduction. The catalyst exhibited excellent activity for CO evolution with a high turnover number (TON, 353 for 24 h), reaction rate (TOF, 14.7 h?1), and product selectivity (97%) under visible-light irradiation. We also succeeded in selective product formation (CO or HCOOH) by changing the basicity of the reaction media. This finding will open new avenues for visible-light driven photoredox catalysis using Ru-based function-integrated photocatalysts.
关键词： Ru complex,visible-light,artificial photosynthesis,CO2 reduction,photocatalysis
更新于2025-09-10 09:29:36
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Preparation of activated carbon nanotube foams loaded with Ag-doped TiO2 for highly efficient photocatalytic degradation under UV and visible light
摘要： Titanium oxide (TiO2) has been widely investigated as a photocatalytic material for degradation of organic pollutant in waste water. However, nanosized granular TiO2 nanoparticles are hard to be recycled and re-utilized in water and many cause secondary pollution of water. Hence, we constructed a foam-like photocatalyst, which was composed of carbonaceous support: activated carbon nanotube foams and Ag-doped TiO2 nanoparticles through a method of a template synthesis and carbonization strategy. The as-prepared photocatalyst evidenced to be hierarchical macroporous and mesoporous and exhibited remarkable photocatalytic performance toward the degradation of unsymmetrical dimethylhydrazine under UV and visible light. The structure characterization and photocatalytic performance investigation confirmed that the enhanced photoresponse was attributed to the high efficiency of charge separation and the surface plasmon resonance effect of metallic Ag. The adsorption synergetic effect of the hierarchical porous structure also played an important role in photodegradation. The as-prepared photocatalyst showed great potential in the treatment of waste water containing organic pollutant.
关键词： Ag-doped TiO2,Photocatalytic degradation,Activated carbon nanotube foams,Unsymmetrical dimethylhydrazine,UV and visible light
更新于2025-09-10 09:29:36
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Architecture of Biperovskite-Based LaCrO <sub/>3</sub> /PbTiO <sub/>3</sub> p–n Heterojunction with a Strong Interface for Enhanced Charge Anti-recombination Process and Visible Light-Induced Photocatalytic Reactions
摘要： Erection of a resourceful p?n heterojunction is a state-of-the-art tactic to flourish the charge anti-recombination process at the heterojunction interface and boost the photocatalytic activities under visible light irradiation. In the present work, we have engineered a new series of PbTiO3/LaCrO3 (PT/LC) p?n heterojunction through a facile two-step combustion process. The structural, interface, and optical analysis distinctly revealed a strong intact between p-type LaCrO3 and n-type PbTiO3, elucidating their electronic channelization and substantial reduction of electron?hole recombination at the PbTiO3/LaCrO3 interface, which extend the lifetime and population of photogenerated charges in the p?n heterojunction material. The asymmetry photocurrent in the opposite directions and an inverted characteristic V-shape Mott?Schottky plot of the optimal PT/LC (7/3) material demonstrated the construction of a p?n heterojunction. The optimal p?n heterojunction possesses excellent photo-stability, and it revealed the highest photocatalytic activity toward degradation of phenol, that is, 86% and hydrogen generation, that is, 343.57 μmol in 2 h. The enhanced photocatalytic activities of the p?n heterojunction materials in comparison to pristine ones are due to the higher separation charge carriers across the p?n heterojunction interface, which was deeply elucidated by carrying out electrochemical impedance spectroscopy, time-resolved photoluminescence spectroscopy, and photoluminescence analyses. These materials pave a new way to design the interface intact photocatalyst with an ultrafast approach for migration of photoexcited electrons across the p?n heterojunction and enhance the photocatalytic activities.
关键词： p?n heterojunction,PbTiO3/LaCrO3,visible light irradiation,photocatalytic activities,charge anti-recombination
更新于2025-09-10 09:29:36
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Dual Catalytic Switchable Divergent Synthesis: An Asymmetric Visible-light Photocatalytic Approach to Fluorine-containing γ-Keto Acid Frameworks
摘要： Herein, we describe a novel and efficient method for constructing a series of fluorine-containing γ-keto acid derivatives through combining visible-light photoredox catalysis and chiral Lewis acid catalysis. With this dual catalytic strategy, a variety of chiral γ-keto amides containing a gem-difluoroalkyl group and a series of fluorine-containing α,β-unsaturated-γ-keto esters were successfully constructed with high stereoselectivities, respectively. A series of experiments showed that the chemoselectivity of this process was highly dependent on the fluorine reagents besides the Lewis acid catalysts. This approach facilitates rapid access to γ-keto acid derivatives, an important class of precursors for pharmaceuticals, plasticizers, and various other additives.
关键词： γ-keto acid derivatives,chiral Lewis acid catalysis,visible-light photocatalysis,asymmetric difluoroalkylation
更新于2025-09-10 09:29:36
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Effective protect of oxygen vacancies in carbon layer coated black TiO2-x/CNNS hetero-junction photocatalyst
摘要： Carbon layer coated black TiO2-x/g-C3N4 nanosheets (C@TiO2-x/CNNS) heterojunction photocatalysts were successfully prepared via a polydopamine dopamine carbonization route for the first time. It was found that the hydrogen evolution rate of C@TiO2-x/CNNS was 417.2 μmol h-1 g-1 under visible light irradiation, which was much higher than that of other prepared photocatalysts in solar water splitting process at the same conditions, and obvious decrease in catalytic activity can be observed after three recycles. The formation of carbon layer on the surface of TiO2-x can effectively protect Ti3+ and oxygen vacancies (Ovs) from oxidation by air and dissolved O2, afterwards much more Ti3+/Ovs are exsited, which can serve as charge carrier traps to inhibit the recombination of light-excited electrons-holes. Therefore, C@TiO2-x/CNNS showed a highly conductivity, rapidly effective electron-hole separation and lower transmission resistance comprehensive consideration of the advantages of carbon layer and hetero-junction, which are of great benefit to the improvement of photocatalytic performance. Hence, a new catalytic tactic namely layer-protection effect was founded and this strategy for boosting hydrogen evolution and protection Ti3+/Ovs may give us some hints on the design of photocatalytic systems.
关键词： black TiO2,visible light H2 evolution,g-C3N4 nanosheet,carbon layer protect oxygen vacancy
更新于2025-09-10 09:29:36
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Spectroscopic Microtomography in the Visible Wavelength Range
摘要： We demonstrate spectroscopic microtomography in the visible wavelength range (450–700 nm) using digital holographic tomography, a wavelength-scanning source, and a variable-optical-path-length strategy. This multidimensional imaging system can directly measure the absorption-coefficient and refractive-index spectra of a three-dimensional specimen. We apply the system developed to characterize three types of polystyrene beads (undyed, blue dyed, and red dyed) as well as oxygenated and deoxygenated single red blood cells.
关键词： visible wavelength range,absorption-coefficient,digital holographic tomography,refractive-index spectra,spectroscopic microtomography
更新于2025-09-10 09:29:36
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Wavelength-Tunable Band-Edge Photoluminescence of Nonstoichiometric Ag–In–S Nanoparticles via Ga <sup>3+</sup> Doping
摘要： The nonstoichiometry of I?III?VI semiconductor nanoparticles, especially the ratio of group I to group III elements, has been utilized to control their physicochemical properties. We report the solution-phase synthesis of non-stoichiometric Ag?In?S and Ag?In?Ga?S nanoparticles and results of the investigation of their photoluminescence (PL) properties in relation to their chemical compositions. While stoichiometric AgInS2 nanoparticles simply exhibited only a broad PL band originating from defect sites in the particles, a narrow band edge PL peak newly appeared with a decrease in the Ag fraction in the nonstoichiometric Ag?In?S nanoparticles. The relative PL intensity of this band edge emission with respect to the defect-site emission was optimal at a Ag/(Ag + In) value of ca. 0.4. The peak wavelength of the band edge emission was tunable from 610 to 500 nm by increased doping with Ga3+ into Ag?In?S nanoparticles due to an increase of the energy gap. Furthermore, surface coating of Ga3+-doped Ag?In?S nanoparticles, that is, Ag?In?Ga?S nanoparticles, with a GaSx shell drastically and selectively suppressed the broad defect-site PL peak and, at the same time, led to an increase in the PL quantum yield (QY) of the band edge emission peak. The optimal PL QY was 28% for Ag?In?Ga?S@GaSx core?shell particles, with green band-edge emission at 530 nm and a full width at half-maximum of 181 meV (41 nm). The observed wavelength tunability of the band-edge PL peak will facilitate possible use of these toxic-element-free I?III?VI-based nanoparticles in a wide area of applications.
关键词： band-edge photoluminescence,multinary semiconductor,quantum dots,nonstoichiometry,I?III?VI2 semiconductor,visible photoluminescence,wavelength tunability,semiconductor nanocrystals
更新于2025-09-10 09:29:36
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Adaptive Thresholding Scheme for Demodulation of Rolling-Shutter Images Obtained in CMOS Image Sensor Based Visible Light Communications
摘要： Light-emitting-diode transmitter and complementary-metal–oxide–semiconductor (CMOS) image sensor receiver based visible light communication is a promising scheme for an optical wireless communication. During the demodulation of the rolling shutter pattern obtained from the CMOS image sensor Rx, due to the high signal fluctuation introduced by the uneven light exposure, special thresholding schemes are needed to correctly identify the data logic. In this work, we propose and demonstrate a modified adaptive scheme (MQA) for the demodulation of the rolling shutter pattern. Experimental bit-error-ratio (BER) measurements using different thresholding schemes at different illuminance are analyzed. The results show that the proposed MQA scheme can provide much lower BER, with similar process latencies when compared with other schemes.
关键词： visible light communication (VLC),Light emitting diode (LED),CMOS image sensor.
更新于2025-09-10 09:29:36