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Water Purification in Dark Conditions Using Photocatalytic Light-leakage Type Plastic Optical Fiber
摘要： In this study, we fabricated a device that can be used for water puri?cation in dark areas by combining a light-leakage type plastic optical ?ber with a photocatalyst. The light-leakage type ?ber was prepared by adding a scattering agent to the ?ber core, and the titanium dioxide photocatalyst was composited by a two-layer coating method. Photocatalytic decomposition of methylene blue was performed by introducing light into the ?ber without direct light irradiation.
关键词： Photocatalyst,Plastic optical ?ber,Water puri?cation
更新于2025-09-23 15:21:01
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Continuous Synthesis of Double-Walled Carbon Nanotubes with Water-Assisted Floating Catalyst Chemical Vapor Deposition
摘要： Double-walled carbon nanotubes (DWCNTs) were synthesized and continuously collected using a water-assisted ?oating catalyst chemical vapor deposition (FCCVD) method. Di?ering from the conventional water-assisted synthesis in which water vapor is one part of the carrier gas mixture, we included de-ionized water in the catalyst system, which achieved a more uniform and controlled distribution for e?cient DWCNT production. Using a water-assisted FCCVD process with optimized conditions, a transition from multi- to double-walled CNTs was observed with a decrease in diameters from 19–23 nm to 10–15 nm in tandem with an elevated Raman IG/ID ratio up to 10.23, and corroborated from the decomposition peak shifts in thermogravimetric data. To characterize the mechanical and electrical improvements, the FCCVD-CNT/bismaleimide (BMI) composites with di?erent water concentrations were manufactured, revealing high electrical conductivity of 1720 S/cm along the bundle alignment (collection) direction, and the nano-indentation tests showed an axial reduced modulus at 65 GPa. A consistent value of the anisotropic ratio at ~3 was observed comparing the longitudinal and transverse properties. The continuous capability of the presented method while maintaining high quality is expected to result in an improved DWCNT mass production process and potentially enhance the structural and electrical applications of CNT nanocomposites.
关键词： water-assisted FCCVD,anisotropic ratio,double-walled carbon nanotube (DWCNT) synthesis,electrical conductivity,nano-indentation
更新于2025-09-23 15:21:01
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Controlled Synthesis of Mesoporous Single-Crystalline TiO2 Nanoparticles for Efficient Photocatalytic H2 Evolution
摘要： Mesoporous single-crystals have emerged as a unique family of functional materials, exhibiting excellent performance in various applications, owing to their well-defined accessible mesoporosity and highly single-crystalline structures. Precise tailoring structures of mesoporous single-crystals at the nanoscale remains an unsolved scientific and technical challenge. Herein, we report a facile and general approach for the synthesis of mesoporous single-crystalline TiO2 nanoparticles (designated as MSC-TNs) with distinctive traits including tunable morphologies, controllable particle sizes, well dispersity, high hydrophilicity, well-defined mesoporosity and single-crystal nature. Specifically, the amount of water employed in the precursor solution was seen to give fine control over the particle sizes and morphologies of MSC-TNs. MSC-TNs with different sizes show excellent photocatalytic activity in production of hydrogen from water. Under the illumination of 300 W Xe lamp, MSC-TNs were shown to provide good photodegradation performance with Rhodamine 6G, as well as H2 production when loaded 1 wt % Pt. In a CH3OH solution H2 was evolved with a rate of 8.98 mmol h-1 g-1, which is significantly higher than with commercial P25 nanoparticles (4.02 mmol h-1 g-1).
关键词： Water Purification,Photodegradation,Photocatalysis,TiO2,Mesoporous
更新于2025-09-23 15:21:01
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Study of solar irradiance and performance analysis of submerged monocrystalline and polycrystalline solar cells
摘要： Underwater photovoltaic (PV) systems supported with modern-day technology can lead to possible solutions for the lack of long-term power sources in marine electronics, navy corps, and many other remotely operated underwater power systems. Currently, most of these systems are powered by conventional batteries, which are bulky, costly, and require periodic maintenance and replacement. Harnessing the underwater Solar energy by using Solar PV cells is simple, reliable, and leads to tremendous advantageous as water itself provides cooling, cleaning, and avoid challenges due to land constraints. The present work encompasses an experimental study on Solar radiation in water and its changes with varying water conditions. Accordingly, the performance of monocrystalline and polycrystalline silicon solar cells with different submerged water conditions and water depths up to 20 cm has been studied. Most importantly, these studies have been carried out with different types of water conditions, consisting of salinity, bacteria, algae, and other water impurities. These investigation results manifest that the percentage decrease of maximum power output in monocrystalline and polycrystalline Solar cells is 65.85% and 62.55%, respectively, in the case of ocean water conditions, whereas in deionized (DI) water conditions, it is 63.06% and 60.72% up to 20 cm. Such results conclude that valuable amount of Solar energy is can be explored underwater. These experimental studies pave the way to explore further to utilize Solar PV cells efficiently in underwater conditions.
关键词： monocrystalline Solar cell,underwater Solar radiation,photovoltaic (PV) technology,PDMS (polydimethylsiloxane),water salinity,polycrystalline Solar cell
更新于2025-09-23 15:21:01
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Application of Generalized Regression Neural Network in Predicting the Performance of Solar Photovoltaic Thermal Water Collector
摘要： Solar photovoltaic thermal water collector (SPV/T-WC) is a hybrid device which converts power from the solar energy in to thermal and electrical simultaneously. The performance of such SPV/T-WC mainly depends on its electrical and thermal power output. Besides the performance of SPV/T-WC, is more sensitive to the transient nature of electrical and thermal power output. Thus a demand for predicting the performance variations in the SPV/T-WC is demand by users. Only limited performance prediction based research works are attempted in the performance prediction of the SPV/T-WC either numerically or by using cognitive models. In this study, two generalized regression neural network (GRNN) models are proposed to predict the transient performance variations in the SPV/T-WC. The two individual objectives of the ?rst and second model include the prediction of overall power output and the overall ef?ciency delivered by an SPV/T-WC system. Both the GRNN models proposed in this study consist of two inputs and single output. In order to train this GRNN model, real time experiments are conducted with stand-alone SPV/T-WC for four continuous days. Then based on such experimental data sets, GRNN models are trained, tested, and validated. The results predicted by the both GRNN models are in good agreement with the real time experimental results. The overall accuracy of the proposed GRNN models in predicting the performance is 95.36% and 96.22% respectively.
关键词： Solar,Water,Collector,Thermal,accuracy,Photovoltaic,GRNN,Prediction
更新于2025-09-23 15:21:01
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Blue LED light-driven photoelectrocatalytic removal of naproxen from water: Kinetics and primary by-products
摘要： Here, we demonstrate the viability of a ZnO/TiO2/Ag2Se thin-film composite synthesized on FTO to degrade the drug naproxen in aqueous solutions by visible-light photoelectrocatalysis (PEC). The experiments were made with 100 mL of solutions containing 5 mg L-1 drug and 50 mM Na2SO4 at natural pH, using a cell equipped with a Pt wire as cathode and the composite as photoanode exposed to a 36 W blue LED lamp. Total degradation was achieved after 210 min of electrolysis at anodic potential of +1.0 V/Ag|AgCl. This resulted from the oxidative action of hydroxyl radicals formed via direct anodic water discharge and through mediated water oxidation by photogenerated holes. The degradation rate decreased at higher naproxen concentration, but the treatment efficiency became higher due the deceleration of the parasitic reactions involving hydroxyl radicals. In chloride medium, the photoanode showed a large ability to produce active chlorine, which contributed to the oxidation of the target molecule. LC-QToF-MS analysis of treated solutions revealed the generation of four primary naphthalenic by-products, from which the initial degradation route of naproxen is proposed.
关键词： Photoelectrocatalysis,Water treatment,Oxidation by-products,Blue LED light,Pharmaceutical residue
更新于2025-09-23 15:21:01
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Improving the performance and economic analysis of photovoltaic panel using copper tubular-rectangular ducted heat exchanger
摘要： This research empirically and theoretically assessed the performance of a solar photovoltaic (PV) panel in five different cooling configurations under the weather conditions of Sanandaj, Iran in September 2018. The findings indicated that, compared to the simple PV mode, the increased mean electrical efficiencies over the whole experiment were 0.27%, 0.5%, 0.72%, 0.6, and 0.88% for the PV/w-XP, PV/w-XD, PV/w-2XDP, PV/a ,and PV/b-2XDP modes, respectively. Further, the highest electrical power for the PV/w-XP, PV/w-XD, PV/w-2XDP, PV/a, and PV/b-2XDP modes increased by 6.8, 12.17, 16.83, 13.17, and 18.92%, respectively compared to the simple PV mode. The monthly electrical output energy the PV/S, PV/w-XP, PV/w-XD, PV/w-2XDP, PV/a, and PV/b-2XDP modes were 28.24 kWh/A, 29.16 kWh/A, 30.34 kWh/A, 31.81 kWh/A, 31.15 kWh/A, and 32.9 kWh/A, respectively. Then, an economic analysis was carried out for the system with two adjustment coefficients. The results showed that although the payback period with an interest rate and an adjustment coefficient of 10% was 2.72 years longer in the PV/b-2XDP than in the PV/S, the annual worth over 20 years was State USD 3.32 (SANA USD 1.07) higher in the PV/b-2XDP mode than in the PV/S mode by considering merely the electrical section. Hence, considering the outlet hot water and air, PV/b-2XDP is more economical to use.
关键词： Water tubular and channel heat exchanger,Photovoltaic panel,Payback period,Thermoelectric
更新于2025-09-23 15:21:01
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[Institution of Engineering and Technology 8th Renewable Power Generation Conference (RPG 2019) - Shanghai, China (24-25 Oct. 2019)] 8th Renewable Power Generation Conference (RPG 2019) - The Method of Grid Disturbance Test for Very Large Capacity Photovoltaic Inverter Based on Hardware-In-Loop Simulation Platform
摘要： A three-dimensional (3-D) finite-difference time-domain (FDTD) algorithm is used in order to simulate ground penetrating radar (GPR) for landmine detection. Two bowtie GPR transducers are chosen for the simulations and two widely employed antipersonnel (AP) landmines, namely PMA-1 and PMN are used. The validity of the modeled antennas and landmines is tested through a comparison between numerical and laboratory measurements. The modeled AP landmines are buried in a realistically simulated soil. The geometrical characteristics of soil’s inhomogeneity are modeled using fractal correlated noise, which gives rise to Gaussian semivariograms often encountered in the field. Fractals are also employed in order to simulate the roughness of the soil’s surface. A frequency-dependent complex electrical permittivity model is used for the dielectric properties of the soil, which relates both the velocity and the attenuation of the electromagnetic waves with the soil’s bulk density, sand particles density, clay fraction, sand fraction, and volumetric water fraction. Debye functions are employed to simulate this complex electrical permittivity. Background features like vegetation and water puddles are also included in the models and it is shown that they can affect the performance of GPR at frequencies used for landmine detection (0.5–3 GHz). It is envisaged that this modeling framework would be useful as a testbed for developing novel GPR signal processing and interpretations procedures and some preliminary results from using it in such a way are presented.
关键词： rough surface,GPR,water puddles,modeling,FDTD,antipersonnel (AP) landmines,roots,dispersive,fractals,Antennas,bowtie,GprMax,grass,vegetation
更新于2025-09-23 15:21:01
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Hidden Isolated OH at the Charged Hydrophobic Interface Revealed by Two-Dimensional Heterodyne-Detected VSFG Spectroscopy
摘要： Water around hydrophobic groups mediates hydrophobic interactions that play key roles in many chemical and biological processes. Thus, the molecular-level elucidation of the properties of water in the vicinity of hydrophobic groups is important. We report on the structure and dynamics of water at two oppositely charged hydrophobic ion/water interfaces, the tetraphenylborate-ion (TPB?)/water and tetraphenylarsonium-ion (TPA+)/water interfaces, which are clarified by two-dimensional heterodyne-detected vibrational sum-frequency generation (2D HD-VSFG) spectroscopy. The obtained 2D HD-VSFG spectra of the anionic TPB? interface reveal the existence of distinct π-hydrogen bonded OH groups in addition to the usual hydrogen-bonded OH groups, which are hidden in the steady-state spectrum. In contrast, 2D HD-VSFG spectra of the cationic TPA+ interface only show the presence of usual hydrogen-bonded OH groups. The present study demonstrates that the sign of the interfacial charge governs the structure and dynamics of water molecules that face the hydrophobic region.
关键词： hydrophobic interfaces,sum-frequency generation,ultrafast spectroscopy,interfacial water,vibrational dynamics
更新于2025-09-23 15:21:01
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Ultrasound assisted deposition of highly stable self-assembled Bi2MoO6 nanoplates with selective crystal facet engineering as photoanode
摘要： The use of crystal facets of photocatalysts is well known as a promising strategy for the design of new photocatalysts with interesting physicochemical features for energy production applications. In this work, Bi2MoO6 thin films were synthesized by two methods, electrodeposition and sonoelectrodeposition. Preferential growth orientation depended on synthesis method. Results suggested that sonoelectrodeposition led to dominate the crystal facet {1 0 0} growth with self-assembled nanoplate morphologies while growth orientation in the {0 1 0} facet was dominant in electrodeposition in the absence of ultrasonic waves. As a highlight result, the {1 0 0} facet shows a smaller band gap, higher photocatalytic water splitting than the {0 1 0} facet. Efficient separation of charge pairs and long life time of photogenerated electrons was observed to be intrinsic features of the {1 0 0} facets. The higher charge transfer was confirmed by a higher photocurrent from linear sweep voltammetry and a smaller Nyquist radius arc. Ultrasound plays a key role in growth orientation and led to a production of homogeneous films with nanoplates which self-assembled together to form a flower-like structure. While in the absence of ultrasound the film has coral-like structure. Highly stable sonoelectrodeposited films exhibited incident photon-to-electron conversion efficiency (IPCE) of 22.4% at the specific wavelength of 500 nm. The sonoelectrodeposition method could act as a promising method for forming new films with specific crystal facet selection and developing as highly efficient photoanodes for PEC water splitting.
关键词： Crystal facet engineering,Coral-like,Water splitting,Bismuth molybdate,Self-assembled nanoplates,Sonoelectrodeposition
更新于2025-09-23 15:21:01