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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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MoS <sub/>2</sub> Nanoflowers as a Gateway for Solar-Driven CO <sub/>2</sub> Photoreduction
摘要： The layering of transition metal dichalcogenides (TMD) has revealed unprecedented engineering opportunities for optoelectronics, field emitter and photocatalysis applications. Precise and controlled intrinsic material property combinations is the crucial demand needed for visible light photocatalysis optimization, which we demonstrate in this work with MoS2 nanoflowers containing abundant edge plane flakes for CO2 photoreduction optimization. This is the first time controlled imperfections and flake thickness through facile CVD synthesis was demonstrated on the nanoflowers, revealing the tuning ability of flake edge morphology, nanoflower size, stacked-sheet thickness, optical band gap energy (Eg) and catalytic function. These influences facilitated Eg tuning from 1.38 to 1.83 eV and the manifestation of the 3R phase prompting improvement to the catalytic behavior. The ‘sweet spot’ of higher catalytic activity during photoreduction experiments was found in those with plentiful nanoflower density and thick edge-site abundance. Ample edge-sites with dangling bonds, and crystal impurities assisted in lowering the Eg to achieve reduced recombination for improved photocatalytic reactions, including those found on what would have been a typical chemically inert basal plane. The production rates of CO improved two-fold after a calculated post-treatment reduction step. This reliable CVD technique for nanoflower synthesis paves the way for enhanced understating of synthetic parameters for defect-laden 2D TMD nanoflower structures. We also note that photocatalysis should consider Mars applications, as deep space humans exploration will be require harvesting of the CO2 rich atmosphere to generate fuel from sustainable resources, such as the sun.
关键词： molybdenum disulfide,band gap tuning,visible light catalyst,transition metal dichalcogenide
更新于2025-09-10 09:29:36
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Photochemical generation of radicals from alkyl electrophiles using a nucleophilic organic catalyst
摘要： Chemists extensively use free radical reactivity for applications in organic synthesis, materials science, and life science. Traditionally, generating radicals requires strategies that exploit the bond dissociation energy or the redox properties of the precursors. Here, we disclose a photochemical catalytic approach that harnesses different physical properties of the substrate to form carbon radicals. We use a nucleophilic dithiocarbamate anion catalyst, adorned with a well-tailored chromophoric unit, to activate alkyl electrophiles via an SN2 pathway. The resulting photon-absorbing intermediate affords radicals upon homolytic cleavage induced by visible light. This catalytic SN2-based strategy, which exploits a fundamental mechanistic process of ionic chemistry, grants access to open-shell intermediates from a variety of substrates that would be incompatible with or inert to classical radical-generating strategies. We also describe how the method’s mild reaction conditions and high functional group tolerance could be advantageous for developing C–C bond-forming reactions, for streamlining the preparation of a marketed drug, for the late-stage elaboration of biorelevant compounds and for enantioselective radical catalysis.
关键词： radicals,SN2 pathway,alkyl electrophiles,photochemical,C–C bond-forming reactions,visible light,enantioselective radical catalysis,nucleophilic organic catalyst
更新于2025-09-10 09:29:36
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Indoor visible light positioning combined with ellipse-based ACO-OFDM
摘要： Visible light communications have recently gained increasing attention as it is appealing for a wide range of applications such as indoor positioning. However, the light-emitting diode-based indoor positioning systems suffer from multipath distortion inside a room, leading to high positioning error. In order to mitigate the effect of multipath distortion of the optical channel, an indoor visible light positioning algorithm combined with ellipse-based asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) is proposed in this study, wherein the real-valued output of orthogonal frequency division multiplexing is modulated onto an ellipse, and only the imaginary value from the complex point on the ellipse is transmitted. Moreover, a received-signal-strength technique is used to determine the location of the receiver, and the Trust- region technique is employed to realise the 3D positioning. Simulation results demonstrate that this proposed algorithm can achieve high positioning accuracy, and the impact of different system parameters on the positioning accuracy is further investigated compared with the systems based on ACO-OFDM.
关键词： indoor positioning,ellipse-based modulation,Trust-region technique,ACO-OFDM,visible light communications,multipath distortion,RSS technique
更新于2025-09-10 09:29:36
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Enhanced inter-lighting interference cancellation using power control to improve the performance of indoor visible light communication systems
摘要： In this study, the authors propose an enhanced inter-lighting interference cancellation (E-ILIC) in order to distinguish the received signals, combating the equal powers at the receiver side and hence improve the average bit error rate (BER) performance of a multiple-input-single-output visible light communication (VLC) system. VLC is a promising technology for indoor environments, it makes use of the light emitting diode (LED) lamps already installed to transmit information through the visible light. When several LEDs transmit simultaneously different data to increase the transmission capacity, it leads to co-channel interference that degrades the BER performance. For this reason, they investigate E-ILIC that is a combination of ILIC with closed loop power control to receive the signals with different power level. It employs power allocation at the transmitter when the received power ratio does not comply with a specific threshold. Furthermore, it reduces significantly the interference between adjacent LED lamps, obtaining useful information at the receiver side. Through computer simulations, E-ILIC achieves the best average BER performance in any user position when the assignment of the power weights is correctly performed on the LEDs.
关键词： MISO,bit error rate,co-channel interference,CCI,BER,visible light communication,inter-lighting interference cancellation,multiple-input-single-output,ILIC,VLC,power control
更新于2025-09-10 09:29:36
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Synthesis of nano-Bi <sub/>2</sub> MoO <sub/>6</sub> /calcined mussel shell composite with enhanced visible light photocatalytic activity
摘要： In this study, a new nano-Bi2MoO6/calcined mussel shell composite photocatalyst was successfully prepared via a facile solvothermal method. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and UV-vis diffuse reflection spectroscopy (DRS) were employed to investigate the morphology, crystal structure, optical properties. It was shown that the nanometer-scaled Bi2MoO6 crystals was assembled with calcined mussel powder, and forming a similar spheroid structure. The obtained samples were displayed higher photocatalytic activities than pure Bi2MoO6 for the degradation of MB under visible-light irradiation. Among them, the Bi2MoO6/ calcined mussel shell mass ratio of 0.7 exhibited the highest activity, and the MB degradation efficiency reached up to 62.46% within 60 min. As a photocatalytic reactor, its recycling performance showed a good stability and reusability. This new composite photocatalyst material holds great promise in the engineering field for the environmental remediation.
关键词： nano-Bi2MoO6,photocatalytic activity,environmental remediation,calcined mussel shell,visible light
更新于2025-09-10 09:29:36
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Rock-salt CdZnO as a transparent conductive oxide
摘要： Transparent conducting oxides (TCOs) are widely used in applications from solar cells to light emitting diodes. Here, we show that the metal organic chemical vapor deposition (MOCVD)-grown, rock-salt CdZnO ternary, has excellent potential as a TCO. To assess this compound, we use a combination of infrared reflectance and ultraviolet-visible absorption spectroscopies, together with Hall effect, to determine its optical and electrical transport characteristics. It is found that the incorporation of Zn produces an increment of the electron concentration and mobility, yielding lower resistivities than those of CdO, with a minimum of 1:96 (cid:2) 10(cid:3)4 X (cid:4) cm for a Zn content of 10%. Moreover, due to a combination of increasing bandgap energy and band filling, the absorption band-edge energy increases from 2.58 eV in CdO up to 2.89 eV for 15% Zn, yielding a largely enhanced transparency in the visible. The low required growth temperatures, together with the scalability of CVD deposition, provide an excellent ground for the integration of this TCO ternary alloy on foreign devices.
关键词： Hall effect,ultraviolet-visible absorption,MOCVD,infrared reflectance,CdZnO,Transparent conducting oxides
更新于2025-09-10 09:29:36
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[IEEE 2018 15th Workshop on Positioning, Navigation and Communications (WPNC) - Bremen, Germany (2018.10.25-2018.10.26)] 2018 15th Workshop on Positioning, Navigation and Communications (WPNC) - Design and Accuracy Evaluation of a RSS-Based Visible Light Positioning Implementation
摘要： In this work the design of a transmitter and receiver for indoor visible light positioning is elaborated. The dedicated design is then deployed to conduct measurements to obtain the estimated distance between transmitter and receiver. The results show that the error on the distance estimation between transmitter and receiver is below 3 cm for a realistic setting and good overall performance is achieved. Some additional measurements are done near a re?ecting surface to estimate the in?uence of the none-line of sight component on the received optical power.
关键词： RSS-Based,Visible Light Positioning,Indoor Positioning,Visible Light Communication,Accuracy Evaluation
更新于2025-09-09 09:28:46
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[Topics in Organometallic Chemistry] || Green Cross-Coupling Using Visible Light for C–O and C–N Bond Formation
摘要： The development of green and sustainable approaches in organic synthesis can provide an environmentally friendly method in the industrial manufacture. Recently, visible-light-mediated photocatalysis has achieved great progress and been a powerful tool to the construction of new chemical bonds in the green synthetic community. This chapter provides an updated summary of visible-light-mediated cross-coupling for C–O and C–N bond formations. Compared with the traditional synthetic methods, the visible-light catalysis provides a new way for the useful compounds synthesis (O-containing and N-containing molecules).
关键词： Visible light,C–O bond,Photoredox catalysis,C–H functionalization,Cross-coupling,C–N bond
更新于2025-09-09 09:28:46
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AIP Conference Proceedings [Author(s) PROCEEDINGS OF THE 3RD INTERNATIONAL SYMPOSIUM ON CURRENT PROGRESS IN MATHEMATICS AND SCIENCES 2017 (ISCPMS2017) - Bali, Indonesia (26–27 July 2017)] - Synthesize, characterization and photosonocatalytic activity of LaMnO3/ZnO nanocomposites for wastewater treatment
摘要： ZnO modified LaMnO3 nanocomposites were prepared using the sol-gel method. The prepared nanocomposite was synthesized in 4 variation of ZnO (1:0.1, 1:0.3, 1:0.5 and 1:1). The LaMnO3/ZnO nanocomposites were characterized using X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The LaMnO3/ZnO shows the orthorhombic structure of LaMnO3 nanoparticles and hexagonal wurtzite of ZnO nanoparticles. The photosonocatalytic activity of LaMnO3/ZnO was tested using methylene blue under the combination of UV or visible light and ultrasonic irradiation. The photosonocatalytic efficiencies performed that the present of ZnO could increase the degradation of MB. LaMnO3/ZnO nanocomposite with molar ratio 1:0.5 show the highest photosonocatalytc activity both under UV or visible and ultrasonic irradiation. Furthermore, the photosonocatalytic activity with combination of UV or visible light and ultrasound irradiation led to more complete degradation compared to use light or ultrasonic irradiation alone. The radical oxidative of the sample was examined by the addition of some scavengers and the results show that hole as the most active species to degrade MB under UV or visible and ultrasonic irradiation.
关键词： UV,visible,ultrasound,LaMnO3,ZnO,Perovskite
更新于2025-09-09 09:28:46
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[IEEE 2018 International Conference on Indoor Positioning and Indoor Navigation (IPIN) - Nantes, France (2018.9.24-2018.9.27)] 2018 International Conference on Indoor Positioning and Indoor Navigation (IPIN) - Real-Time Localization and Tracking Using Visible Light Communication
摘要： In this paper an optical indoor positioning system is proposed, which utilizes modulated LED lights as anchor points, deployed in known positions. The sensor, deployed on the tracked object (e.g. autonomous vehicle), is an ordinary camera facing upwards. The system is able to estimate the position and orientation of the moving object in real-time, based on the camera’s image stream, containing images of the anchor points. The paper contains comprehensive analysis on the possible error sources and their effect on the positioning accuracy. Real measurement tests show that the accuracy of the system is in the low centimeter range even if the tracked camera moves with a speed of 1 m/s.
关键词： indoor positioning,heuristic data fusion,Visible Light Communication,fisheye camera,real-time tracking
更新于2025-09-09 09:28:46