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- 2019
- charge – discharge energy efficiency
- Lithium-ion battery
- degradation diagnosis
- photovoltaic surplus energy
- working electric vehicle
- Electrical Engineering and Automation
- Ritsumeikan University
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Self-assembled BiOCl/Ti3C2T composites with efficient photo-induced charge separation activity for photocatalytic degradation of p-nitrophenol
摘要： Cocatalysts play an important role in increasing the photogenerated electron-hole separation rate of catalytic materials. Here, we selected a novel 2D material Ti3C2Tx (Tx = –OH, –O) as a cocatalyst and synthesized BiOCl/Ti3C2Tx (named as BT-n n = 0, 0.5, 1.0, 2.0, 4.0) composite materials by electrostatic self-assembly. We carefully characterized the structure, morphology and photoelectric performance of the composites, finding that we successfully synthesized 2D/2D BiOCl/Ti3C2Tx materials. The photocatalytic performance of the composites was evaluated by degradation of p-nitrophenol as a pollutant under simulated illumination. Among the composites obtained, BT-2.0 showed the best photocatalytic performance; specifically, its removal rate reached 97.86% and its degradation rate was about 3.3 times that of BT-0. Free radicals in the photocatalytic process were tested by electron paramagnetic resonance, which showed that superoxide radicals and holes are the most active free radicals in the system due to the higher photogenerated electron separation efficiency of BT-2.0. Therefore, constructing a heterojunction with Ti3C2Tx as a cocatalyst can improve the photocatalytic activity of BiOCl, which may provide new insights into the selection of novel co-catalytic materials in the field of photocatalysis.
关键词： p-nitrophenol,photocatalytic degradation,MXene,superoxide radicals,BiOCl
更新于2025-09-23 15:21:01
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Explosive thermal exfoliation of intercalated graphitic carbon nitride for enhanced photocatalytic degradation properties
摘要： Dicyandiamide derived graphitic carbon nitride (g-C3N4) was chemically intercalated by concentrated H2SO4 firstly, followed by a rapid heating treatment. Molecules between the stacking layers of g-C3N4 produced an explosive effect upon rapid heating to thermally exfoliate g-C3N4 into porous structures. The appearance color of g-C3N4 changed from light yellow to grey after heating treatment indicating the enhanced light absorption properties, which were identified by the UV-vis absorption test. In addition, photoluminescence intensities of porous g-C3N4 were obviously suppressed compared to those of bulk g-C3N4 samples, indicating the prevention of the recombination process of photogenerated electron-hole pairs. As a result of these simultaneous modifications in texture, optical and electronic properties, the photodegradation kinetics of crystal violet on the catalyst surface can be improved by 4.75 times.
关键词： heating treatment,g-C3N4,photocatalytic degradation,exfoliation
更新于2025-09-23 15:21:01
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Online Degradation Detection/Prediction Method for Current Transfer Ratio of Photo-Coupler Installed in Digitally-Controlled Switching Mode Power Supply
摘要： The software-implemented degradation detection/prediction of the current transfer ratio (CTR) of a photo-coupler installed in a digitally-controlled switching mode power supply was studied. The photo-coupler is one of the key devices in an isolated power supply circuit, which transmits a voltage/current signal to a controller though the isolation gap. If the CTR of the photo-coupler degrades to halfway between the normal value and the threshold of the hardware protection circuit, overvoltage/current may be supplied continuously to the load circuit and possibly cause a severe failure. By comparing the theoretical pulse width modulation (PWM) duty, which is calculated from the input/output voltage and the pre-measured power supply circuit e?ciency, and the applied PWM duty, which is calculated via feedback control, CTR degradation is detectable online. In this paper, we describe the concept of this method and verify it using both simulation and prototyping circuits.
关键词： digitally-controlled power supply,current transfer ratio,failure prediction,degradation,photo-coupler,CTR
更新于2025-09-23 15:21:01
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Visible light photocatalytic degradation of tetracycline with porous Ag/graphite carbon nitride plasmonic composite: Degradation pathways and mechanism
摘要： Ag/g-C3N4 plasmonic photocatalysts with porous structure ( Ag/PCN ) were successfully synthesized via a thermal exfoliation strategy and photo-reduction method. Owing to the combined merits of porous structure and surface plasmon resonance effect of silver nanoparticles, the Ag/PCN catalysts exhibited excellent photocatalytic performance for the degradation of antibiotic agents. With the optimal Ag loading, the Ag/PCN-2 catalyst exhibited the optimal catalytic activity for TC degradation under visible light, which shows about 11.8 times enhancement in the photocatalytic removal efficiency as compared to pure g-C3N4, respectively. This phenomenon can be attributed to the increased specific surface area, broadened visible light absorption and improved charge separation. The radical quenching results confirmed that h+ and ·O2- radicals were the major active species during removal of TC. The degradation of TC is increased with the increment of Ag/PCN-2 catalysts, and the optimum catalyst was found to be 1.67 g/L. The hindering effect of selected of anions ( Cl-, CO3-, H2PO4- ) was found to follow the order H2PO4- > CO3- > Cl-. Ag/PCN-2 sample also possessed high stability after six cycles of reuses. Furthermore, the possible degradation pathways of TC and photocatalytic mechanism over Ag/PCN-2 were proposed in detail.
关键词： g-C3N4,Antibiotic,Degradation pathway,Photocatalysis,Porous structure,Ag
更新于2025-09-23 15:21:01
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Fabrication of highly durable polysiloxane-Zinc Oxide (ZnO) coated Polyethylene Terephthalate (PET) fabric with improved ultraviolet resistance, hydrophobicity, and thermal resistance
摘要： Developing a universal strategy to improve the properties of PET fibers, such as UV resistance, hydrophobicity, and thermal resistance, is highly desirable in expanding the application of PET fibers. Herein, a highly durable and robust ZnO layer was deposited onto polyethylene terephthalate (PET) fabric via radiation-induced graft polymerization (RIGP) of γ-methacryloxypropyl trimethoxysilane (MAPS) and the subsequent sol-gel in situ mineralization with zinc acetate to produce wurtzite nanocrystalline ZnO. The as-obtained material, denoted as PET-g-PMAPS/ZnO. The interfacial layer consisted of Zn-O-Si and Si-O-Si covalent bonds not only leads to an improvement in adhesion between ZnO nanoparticles and its support, but it also overcomes the poor film-forming ability of inorganic particles. Most importantly, photocatalytic self-degradation of its organic support caused by the high photocatalytic activity of ZnO can be eliminated because of high bond energy of the organic-inorganic hybrid structure. PET-g-PMAPS/ZnO exhibited excellent thermal resistance, UV resistance and durability. Superhydrophobicity was achieved by simply annealing the PET-g-PMAPS/ZnO fabric at 200 °C in ambient air, and the coated fabric still retains its superhydrophobicity after 40 laundering cycles test and even stored for a few weeks. This study presents an effective method to overcome the bottle-necks in growing inorganic nanocrystals on polymeric supports surface.
关键词： ZnO,UV resistance,self-degradation,polyethylene terephthalate fabric,radiation-induced graft polymerization
更新于2025-09-23 15:21:01
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Ag/AgCl/Ag2MoO4 composites for visible-light-driven photocatalysis
摘要： Ag2MoO4 shows low photocatalytic activity under visible light. It would be interesting to develop Ag2MoO4-based composite/heterojunction photocatalysts working efficiently under visible light. Herein, novel Ag/AgCl/Ag2MoO4 composites were obtained via photoreduction of AgCl/Ag2MoO4 composites prepared by sequential precipitation. The composition, morphologies, and optical properties of the samples were studied via various characterization techniques. Photocatalytic degradation of rhodamine B (RhB), methylene blue (MB), methyl orange (MO), norfloxacin (NOF), and tetracycline hydrochloride (TC) solutions was conducted under visible-light irradiation. An optimal Ag/AgCl/Ag2MoO4 catalyst showed much higher photocatalytic activity than Ag2MoO4, and it also showed reasonably fine recyclability. Through radical-capturing experiments, photogenerated holes (h+) were determined to be the main active species whereas hydroxyl radicals (?OH) were found to play a secondary role in photocatalysis. Possible photocatalytic mechanisms were proposed.
关键词： Ag2MoO4,AgCl,degradation,photocatalysis,dyes
更新于2025-09-23 15:21:01
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Photocatalytic degradation of phenol wastewater over Z-scheme g-C3N4/CNT/BiVO4 heterostructure photocatalyst under solar light irradiation
摘要： A series of carbon nanotubes (CNT) modified g-C3N4/BiVO4 photocatalysts were synthesized via wet-impregnation method and evaluated via degradation of phenol under solar light irradiation. The physicochemical properties of the as-developed photocatalyst were characterized using FTIR, XRD, FESEM, XPS, SAP and DR-UV Vis. The formation of g-C3N4/CNT/BiVO4 photocatalysts resulted in remarkable enhancement in the performance in which almost six times higher degradation rate in comparison to the pristine g-C3N4 and obeyed the pseudo-first-order kinetics and Temkin adsorption model. Congruously, the synergistic interaction between 2 wt. % of CNT and 5 vol. % of H2O2 as an oxidizing agent was capable of removing 80.6 % of phenol within 120 minutes. The profound photodegradation performance monitored was attributed to the better crystallinity structure obtained as shown in XRD and XPS analysis. Furthermore, the intimate contact between the CNT, g-C3N4 and BiVO4 in the heterostructure sample as shown in FESEM micrograph images does help in allowing a smooth electron-hole pair separation and migration, resulting in more available ?OH and ?O2ˉ radicals for photocatalytic degradation activities. The possible Z-scheme reaction mechanism has been proposed and active species trapping experiments have been carried out to find the role of active radical species responsible for the phenol degradation. Additionally, the g-C3N4/CNT/BiVO4 photocatalysts retained excellent stability even after several cycles. Congruently, a mathematical representation for understanding the interaction between CNT loading and H2O2 for photodegradation of phenol using response surface methodology (RSM) was successfully generated.
关键词： phenol degradation,bismuth vanadate,carbon nanotube,wastewater,graphitic carbon nitride,photocatalyst
更新于2025-09-23 15:21:01
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Photovoltaic Degradation Rate Affected by Different Weather Conditions: A Case Study Based on PV Systems in the UK and Australia
摘要： This article presents the analysis of degradation rate over 10 years (2008 to 2017) for six different photovoltaic (PV) sites located in the United Kingdom (mainly affected by cold weather conditions) and Australia (PV affected by hot weather conditions). The analysis of the degradation rate was carried out using the year-on-year (YOY) degradation technique. It was found that the degradation rate in the UK systems varies from ?1.05% and ?1.16%/year. Whereas a higher degradation ranging from ?1.35% to ?1.46%/year is observed for the PV systems installed in Australia. Additionally, it was found that in the Australian PV systems multiple faulty PV bypass diodes are present due to the rapid change in the ambient temperature and uneven solar irradiance levels influencing the PV modules. However, in cold weather conditions (such as in the Northern UK) none of the bypass diodes were damaged over the considered PV exposure period. Furthermore, the number of PV hot spots have also been observed, where it was found that in the UK-based PV systems the number of hot spotted PV modules are less than those found in the Australian systems. Finally, the analysis of the monthly performance ratio (PR) was calculated. It was found that the mean monthly PR is equal to 88.81% and 86.35% for PV systems installed in the UK and Australia, respectively.
关键词： performance analysis,photovoltaic systems,performance ratio,degradation,hot-spots
更新于2025-09-23 15:21:01
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Comparison of acetaminophen degradation in UV-LED-based advance oxidation processes: Reaction kinetics, radicals contribution, degradation pathways and acute toxicity assessment
摘要： Ultraviolet light emitting diode (UV-LED)-based advanced oxidation processes (AOPs) including UV-LED/chloramine (UV-LED/NH2Cl), UV-LED/hydrogen peroxide (UV-LED/H2O2) and UV-LED/persulfate (UV-LED/PS), were adopted for acetaminophen (AAP) removal. Results showed that AAP could be effectively degraded by the hybrid processes compared to solely using with UV irradiation and oxidants. The AAP degradation in the three UV-LED-based AOPs were in the order of UV-LED/PS N UV-LED/H2O2 N UV-LED/NH2Cl and followed a pseudo-?rst-order kinetics. The degradation rate constant (kobs) increased with increasing oxidant dosage, whereas overdosing lowered the AAP degradation. The second-order rate constants of HO?, SO4??, and Cl? with AAP were calculated as 5.15 × 109, 7.66 × 109 and 1.08 × 1010 M?1 s?1, respectively. Under neutral conditions, the contributions of UV-LED, HO?, and Cl? to AAP degradation were 4.21%, 60.15% and 35.64% in the UV-LED/NH2Cl system, whereas the respective contributions of UV-LED, HO? and SO4?? to AAP degradation were 2.09%, 22.84% and 75.07% in UV-LED/PS system, respectively. Meanwhile, the corresponding contributions of the involved reactive species were found to be pH-dependence. The natural organic materials (NOM) inhibited the ? had different effects on AAP degradation in the ?, and NO3 AAP degradation, and the presence of Cl?, HCO3 three hybrid processes. The AAP degradation was signi?cantly inhibited in the three UV-LED-based AOPs in real water. In addition, the intermediate products were also identi?ed, and possible degradation pathways were proposed in the three UV-LED-based AOPs. The acute toxicity bioassay using bacterium Vibrio ?scheri suggested that the UV-LED/PS process was more effective than the UV-LED/H2O2 and UV-LED/NH2Cl processes in reducing the acute toxicity of the reacted AAP solution. Among the three UV-LED-based AOPs, the UV-LED/PS was found to be the most ef?cient process for AAP degradation.
关键词： Acute toxicity,Rate constants,UV-LED-based AOPs,Degradation pathways,Acetaminophen
更新于2025-09-23 15:21:01
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Characterizing the transformation of aquatic humic substances exposed to ultraviolet radiation using excitation–emission matrix fluorescence spectroscopy and PARAFAC
摘要： It is important to understand the change in aquatic humic substances (AHS) induced by light due to the upward trend in ultraviolet (UV) radiation reaching the surface of the Earth. Changes in the quantity and quality of AHS in AHS-rich wetland water exposed to UV-A or UV-B light were determined using 3-dimensional excitation–emission matrix (EEM) fluorescence spectroscopy combined with parallel factor analysis (PARAFAC) and a resin isolation method. The dissolved organic carbon and AHS-carbon concentrations decreased via photodegradation with UV-A or UV-B exposure. The decreases in both carbon concentrations were greater when exposed to UV-B than when exposed to UV-A. Three AHS-like components were detected by EEM-PARAFAC: AHS-1, AHS-2, and AHS-3. AHS-1 and AHS-3 were degraded more by UV-A and UV-B exposure, respectively. AHS-2 was degraded slightly by UV-A exposure, whereas exposure to UV-B generated AHS-2 in the presence of low-molecular-weight compounds, and then underwent photodegradation. AHS-1 exposed to UV-A and AHS-3 exposed to UV-A or UV-B photoflocculated at day 14. The humification index indicated that UV-A exposure led to the preferential photodegradation of AHS, whereas UV-B exposure not only caused AHS degradation but also the degradation or photoflocculation of other compounds with simple structures. AHS changed little in the dark, demonstrating that bacterial effects on AHS were relatively unimportant. The processes of humification and flocculation are important in removing and sequestering carbon from its active cycle. Therefore, the degradation and transformation of AHS exposed to UV can have a major impact on aquatic ecosystem processes.
关键词： photochemical degradation,ultraviolet radiation,aquatic humic substances (AHS),EEM-PARAFAC,dissolved organic matter (DOM)
更新于2025-09-23 15:21:01