- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 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
-
Acid-treated Fe-doped TiO2 as a high performance photocatalyst used for degradation of phenol under visible light irradiation
摘要： The photocatalytic activity of Fe-doped TiO2 nanoparticles is significantly increased by an acid-treatment process. The photocatalyst nanoparticles were prepared using sol–gel method with 0.5 mol% ratio of Fe:Ti in acidic pH of 3. The nanoparticles were structurally characterized by means of X-ray diffraction (XRD), high-resolution transmission electron microscope (HRTEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance spectroscopy (DRS). It was observed that the photocatalytic activity suffered from an iron oxide contaminating layer deposited on the surface of the nanoparticles. This contamination layer was removed using an HCl acid-treatment process. The photocatalytic activity using 500 mg/L of Fe0.5-TiO2 in a 10 mg/L of phenol solution increased significantly from 33% to 57% (about 73% increase in the performance), within 90 min of reaction time under visible light irradiation. This significant improvement was achieved by removing the iron oxide contamination layer from the surface of the nanoparticles and adjusting pH to mild acidic and basic pHs.
关键词： Kinetics,Iron doping,Phenol degradation,Visible light,Photocatalyst
更新于2025-11-14 15:25:21
-
Impact of doped metals on urea-derived g-C3N4 for photocatalytic degradation of antibiotics: Structure, photoactivity and degradation mechanisms
摘要： Metal doping is an appealing modification strategy of graphitic carbon nitride (g-C3N4) to improve its photocatalytic activity. The interactions of g-C3N4 precursors with metals, however, has often been underappreciated, which can induce great impacts on g-C3N4 formation and properties. Herein, the impacts of metals (Na, K, Ca, Mg) on the morphology, structure, and photoactivity of urea-derived g-C3N4 were investigated. Our TEM and XPS results confirmed that the interactions of doped metals with urea precursors lead to the incorporation of O atoms from urea molecules into the framework of g-C3N4. Due to the synergistic effects of the metals and structural O atoms, doped g-C3N4 performed an elevated photodegradation of antibiotics under the visible light irradiation, which was attributed to the enhanced light-harvesting and reduced charge recombination. In addition, the doped metals presented uneven regulation on the band structures and morphology of g-C3N4. As a result, both superoxide and hydroxyl radicals were generated by g-CN-Na and g-CN-K, whereas, only superoxide radicals were involved in g-CN, g-CN-Ca and g-CN-Mg. Consequently, diversified photodegradation mechanisms for enrofloxacin (ENR) were observed that the g-CN, g-CN-Ca and g-CN-Mg reaction systems mainly attacked the piperazine moiety of ENR while g-CN-Na and g-CN-K provided additional photodegradation pathway by attacking quinolone core of ENR. The present work could provide new insights into further understanding of doping chemistry with g-C3N4.
关键词： Metal doping,Photocatalytic degradation of antibiotics,g-C3N4,Visible light photocatalysis
更新于2025-11-14 15:24:45
-
Handling Electromagnetic Radiation beyond Terahertz using Chromophores to Transition from Visible Light to Petahertz Technology
摘要： An increase of the operating frequencies of electromagnetic waves leads from the well-established terahertz technology to the visual and reaches petahertz radiation. It is shown that electromagnetic radiation close to petahertz is attractive for technology where knowledge about radio waves can be applied. The dimensions of such radiation are still classically macroscopic; however, molecular components such as resonators were used where quantum mechanics rules have to be considered. Constructions of coupled resonators for energy transfer are as well demonstrated as molecular components for optical metamaterials.
关键词： Dyes,FRET,Energy transfer,Reflectance,Petahertz,Visible light,Resonators,Metamaterials,Terahertz,Electromagnetic radiation
更新于2025-09-23 15:23:52
-
Metal Sulfide Photocatalysis: Visible-Light-Induced Organic Transformations
摘要： Transition-metal sulfides belong to an important subgroup of semiconductor photocatalysts that could promote a variety of valuable redox reactions under mild conditions. One notable merit of metal sulfides is their relatively smaller bandgaps than metal oxides, which in turn make sure that many of them can directly utilize visible light. Historically, the deployment of metal sulfides for visible-light-induced organic transformations took place shortly after the genesis of the research field of heterogeneous photocatalysis. In this review, we primarily focus on recent state-of-the-art advancements of metal sulfide photocatalysis aimed at visible-light-induced selective organic transformations. Interests in this specific branch of photocatalysis have been rekindled due to the new methods for materials synthesis; the pursuit of new mechanisms; or the integration of metal sulfides with metal oxides, metal nanoparticles or other emerging materials. Thus we categorize them into four sections according to the different strategies in developing novel or more efficient organic processes. Binary and ternary metal sulfides, usually associated with new materials synthesis and mechanistic insights, can be used directly for visible-light-induced organic transformations. This is the basis of other further developments and will be introduced firstly. Next, the cooperation between metal sulfides and metal oxides or metal nanoparticles can be conducive to many photocatalytic systems. These developments will be discussed in the next two ensuing sections. Furthermore, the integration of metal sulfides with recent developed emerging materials such as metal-organic frameworks (MOFs), graphene and graphitic carbon nitride (g-C3N4) would be discussed in another section to highlight the importance of merging metal sulfides with these materials. We attempt to keep an impartial panorama of these four distinctive sections even though the phases of development are quite different among sections, leaving plenty of room for the future expansion of this burgeoning area.
关键词： Metal Sulfide,Selective Oxidation,Photocatalysis,Visible Light,Selective Reduction
更新于2025-09-23 15:23:52
-
The Use of Magnetic Orientation as a Pinning Modality for Investigation of Photon-Magnon Interactions in Magnetic Nanoparticle Systems
摘要： In this work, an experimental setup to study the dependence of a visible-light transmission through a magnetic granular film on the magnetic field direction was presented. The results measured the transmission (T) of the visible light, with the wavelengths (λ) were in the range from 560 to 695 nm, by the magnetic nanogranular films Cox-(Al2O3)100-x system, with Co compositions are x = 10 ÷ 45 at.%, as a function of the magnetic field direction were reported. These investigations were carried out under an external magnetic field of H = 400 Oe, which directs to the normal of the sample surface by an angle varied in the range of θ = 0° ÷ 45°, to magnetize the magnetization direction of all the Co particles following this direction. Consequently, the angle θ between the magnetization direction with the incident-light direction, which sets as the optical axis of the system and always keeps fixedly to the normal of the sample surface, is established. The experimental results showed the different dependencies of T on the angle θ, the magnetic field H, the Co composition x, and the wavelength λ. These dependencies attributed to a behavior that relates to so-called photon-magnon interaction.
关键词： Ferromagnetic Nanoparticle (FMNP),Visible-Light Transmission,Magnetic Nanogranular Film (MNGF),Plasmonic Spin,Photon-Magnon Interaction
更新于2025-09-23 15:23:52
-
[IEEE 2018 International Conference on Advanced Technologies for Communications (ATC) - Ho Chi Minh City, Vietnam (2018.10.18-2018.10.20)] 2018 International Conference on Advanced Technologies for Communications (ATC) - Keynote talk #2: Visible light communications for 5G-and-beyond wireless telecommunications networks
摘要： Artificial general lighting sources are currently evolving through the traditional fluorescent and incandescent sources to the modern energy saving light bulbs and now white light emitting diodes (LEDs). This trend has been spurred on through global awareness of the necessity for reducing the size of our carbon footprint. The introduction of solid state LED lighting has attracted the attention of communications engineer's worldwide, enabling the achievement of the dual functionality of room illumination whilst simultaneously transmitting wireless data via visible light communication (VLC), or Light Fidelity (LiFi), in optical spectrum regime. Although the existing wireless networks are primely dominated by radio-based technology, the emerging VLC will play increasingly important role in future wireless telecommunications landscape. It is anticipated that both spectrum regimes, radio and optical, will eventually contribute equally for the next network generation, especially in nanocell and picocell network structures. This talk will outline the growth of optical wireless communications including VLC, and present the challenges and roadmap of the technology for the future generation of wireless networks.
关键词： Visible Light Communications,Networks,LED,LiFi
更新于2025-09-23 15:23:52
-
Activated carbons with adsorbed cations as photocatalysts for pollutants degradation in aqueous medium
摘要： Oxidized activated carbon (AC) based on commercial coconut-shell carbon Aquacarb 607C has been prepared. This AC has micro-mesoporous structure and contains surface carboxyl and phenol/enol groups. Cu- and Co-containing ACs have been synthesized via ion-exchange in acid medium. According to potentiometric titration and XPS data, cation-exchanged forms of AC contain about 0.5% of metal ions. Such cation-containing ACs possess narrowed band gap compared oxidized AC as it is observed for doped oxides. Oxidized and cation-containing ACs have been tested as catalysts in photodegradation of dyes and phenol under UV- and visible irradiation. Initial oxidized AC is photoactive toward rhodamine B and methyl orange under UV illumination but inactive under visible light. For the first time it is shown that cation-exchanged forms of AC have enhanced activity towards rhodamine B, methyl orange and phenol in both UV and visible region. Therefore, the principal possibility of improving the photocatalytic properties of AC by introducing a minimal amount of copper and cobalt cations is shown.
关键词： Cation-exchanged forms,Decolourisation and mineralization,UV and visible irradiation,Activated carbon,Photocatalytic degradation
更新于2025-09-23 15:23:52
-
Physical, Thermal and Spectroscopic Studies on Biofield Treated p-Dichlorobenzene
摘要： Para-dichlorobenzene (p-DCB) is widely used as a chemical intermediate in manufacturing of dyes, pharmaceuticals, polymers and other organic synthesis. The aim of present study was to evaluate the impact of biofield treatment on physical, thermal, and spectroscopic properties of p-dichlorobenzene. The p-dichlorobenzene sample was divided into two groups that served as treated and control. The treated group received Mr. Trivedi’s biofield treatment. Subsequently the control and treated samples were evaluated using X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and UV-Vis spectroscopy. XRD result showed an increase in crystallite size (4.93%) along with alteration in peak intensity of treated sample as compared to control. Furthermore, DSC analysis results showed that the latent heat of fusion of treated p-dichlorobenzene was considerably reduced by 8.66% as compared to control. The reduction in melting point of treated sample (54.99°C) was also observed as compared to control (57.01°C) p-dichlorobenzene. Moreover, TGA/DTG studies showed that Tmax (temperature, at which sample lost maximum of its weight) was increased by 6.26% and weight loss per degree celsius (°C) was decreased by 12.77% in biofield treated p-dichlorobenzene as compared to control sample. It indicates that thermal stability of treated p-dichlorobenzene sample might increase as compared to control sample. However, no change was found in UV-Vis spectroscopic character of treated p-dichlorobenzene as compared to control. These findings suggest that biofield treatment has significantly altered the physical and thermal properties of p-dichlorobenzene, which could make it more useful as a chemical intermediate.
关键词： Differential scanning calorimetry,Para-dichlorobenzene,Thermogravimetric analysis,and UV-Visible spectroscopy,Biofield treatment,X-ray diffraction study
更新于2025-09-23 15:23:52
-
Graphene oxide-based zirconium oxide nanocomposite for enhanced visible light-driven photocatalytic activity
摘要： In the present investigation, an efficient visible light-active, graphene oxide-based zirconium oxide nanocomposite (GO–ZrO2) has been synthesized by co-precipitation method. The synthesized photocatalyst was characterized by XRD, FTIR, FE-SEM, EDS, TEM, TGA, PL, UV-DRS and BET surface area analysis. The characterization results illustrate the homogeneous dispersion of ZrO2 nanoparticles in the GO–ZrO2 nanocomposite with excellent harmony between GO and ZrO2 nanoparticles. The photocatalytic efficiency of the synthesized GO–ZrO2 nanocomposite was evaluated by photodegradation of hazardous, water-soluble rhodamine B and methylene blue dyes under visible light irradiation. The 90% photocatalytic degradation of rhodamine B dye (with initial conc. 30 mg/L) was observed in 105 min of visible light irradiation, while 99.23% of methylene blue (with initial conc. 100 mg/L) dyes degradation was observed in just 60 min using 25 mg/100 ml dose of GO–ZrO2 nanocomposite as a photocatalyst. The mechanistic investigation using scavengers suggest that the superoxide (O2·?) is the most reactive species involved in the photodegradation of organic dyes. The synthesized photocatalyst GO–ZrO2 nanocomposite also exhibits excellent thermal stability and reusability.
关键词： Methylene blue,Rhodamine B,Photocatalytic activity,Zirconium oxide,Graphene oxide,Visible light,Co-precipitation method
更新于2025-09-23 15:23:52
-
Covalent organic framework as an efficient, metal-free, heterogeneous photocatalyst for organic transformations under visible light
摘要： Visible-light active, heterogeneous, and organic photocatalysts exhibit a more sustainable and environmentally friendly alternative to classical metal-based catalysts. Two-dimensional covalent organic frameworks (2D-COFs) with permanent porosity, columnar π-arrays and excellent stability, that can become an excellent platform for heterogeneous photocatalysis of organic transformations. Here we report a predesigned imine-based COF with electron donor and acceptor structure. And new framework possesses large surface area, high crystallinity, outstanding stability and broad absorption range in the visible-light region as well as good photoelectric response characteristics. Importantly, it was found to be a highly effective heterogeneous photocatalyst for reductive dehalogenation of phenacyl bromide derivatives and α-alkylation of aldehydes under irradiation of visible-light. In addition, the COF gave good recyclability and could be reused after a simple separation manipulation. The current present still reveals a great prospect for 2D-COFs as metal-free, heterogeneous photocatalysts for organic transformations.
关键词： visible light,photocatalysis,heterogeneous catalysis,metal-free,covalent organic frameworks
更新于2025-09-23 15:23:52