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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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Photocatalytic degradation of Microcystin-LR by visible light active and magnetic, ZnFe2O4-Ag/rGO nanocomposite and toxicity assessment of the intermediates
摘要： In this work, we aimed to study photocatalytic degradation of Microcystin-LR (MC-LR), a cyanotoxin known to cause acute as well as chronic toxicity and even mortality. The nanocomposite (NC) based on zinc ferrite (ZnFe2O4) was modified with graphene oxide (GO) and Ag nanoparticles (NPs) to enhance its photocatalytic properties under visible light. The so-formed ZnFe2O4-Ag/rGO NC exhibited superior performance in visible light allowing complete degradation of MC-LR within 120 mins of treatment with pseudo rate constant, k = 0.0515 min-1, several times greater than other photocatalysts, TiO2 (k = 0.0009 min-1), ZnFe2O4 (k = 0.0021 min-1), ZnFe2O4-Ag (k = 0.0046 min-1) and ZnFe2O4/rGO (k = 0.007 min-1) respectively. The total organic carbon analysis revealed that only 22% of MC-LR was mineralized on 120 mins of treatment time indicating presence of different intermediate by-products. The intermediates formed during photocatalytic treatment were identified using liquid chromatography–mass spectrometry (LCMS) based on which probable degradation pathways were proposed. The attack from ?OH radicals formed during the photocatalytic process resulted to hydroxylation and subsequent cleavage of diene bond. The toxicity assessment with Daphnia magna revealed that the degradation process has alleviated toxicity of the MC-LR and no toxic intermediates were formed during the treatment which is very important from eco-toxicological view point. Therefore, ZnFe2O4-Ag/rGO has a good potential in the field of environmental applications as visible light active and magnetic photocatalyst with enhanced performance.
关键词： Photocatalytic degradation,Toxicity,Daphnia magna,Microcystin,Intermediates
更新于2025-09-23 15:23:52
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Atomic layer deposition of hybrid metal oxides on carbon nanotube membranes for photodegradation of dyes
摘要： Synthetic dye pollution is a worldwide problem and quick remedies are urgently needed. Photocatalysis is a promising method to solve this problem and carbon nanotubes (CNTs) are promising components in producing high-performance composite photocatalysts. Nevertheless, the strong hydrophobicity dramatically impedes its application in aqueous environments. In this study, hydrophilic CNT-hybrid metal oxides (ZnO and TiO2) membranes were prepared by atomic layer deposition (ALD). We demonstrate that ALD is an efficient and flexible method to enhance the photocatalytic activity of CNT-based membranes, especially the membranes used in wastewater treatments. The hybrid hexagonal wurtzite ZnO and anatase TiO2 on CNTs after calcination could effectively enhance electron transfer and reduce photo-generated electron-holes recombination. The membranes exhibit preferable photocatalytic activity and stable reusability in dye degradation. This strategy of "ALD on CNTs" is expected to create other CNT-based membranes with additional functionalities and has bright prospect for wastewater treatments.
关键词： Carbon nanotubes,Photocatalytic degradation,Hybrid metal oxides,Atomic layer deposition
更新于2025-09-23 15:23:52
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Experimental data on the degradation of caffeine by photo-electro-fenton using BDD electrodes at pilot plant
摘要： Emerging contaminants (EC) are an imminent risk due to potential toxicity to aquatic ecosystems and human beings. This type of contaminants is found in low concentrations and usually present incomplete or inefficient removal by conventional treatments, which entail its permanence and constant increase. Advanced Oxidation Processes (AOP) are an alternative for the elimination of dangerous and resistant substances in wastewater. So, this research evaluates the caffeine degradation in aqueous solution by AOP, such as: Fenton, Electro-Oxidation (EO) with boron doped diamond (BDD) electrodes, Electro-Fenton (EF) and Photo-Electro-Fenton (PEF). The influences of pH, concentration of the supporting electrolyte and specific electric charge were investigated using a Taguchi's factorial design, which allowed to identify the contribution of each variable in the process. The data obtained in this work can be useful for scaling process and cost analysis because it provide the information at pilot plant scale.
关键词： Chemical engineering,Taguchi design,BDD electrodes,Advanced oxidation process,Caffeine degradation
更新于2025-09-23 15:23:52
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Different Mathematical Spectrophotometric Methods for Determination of Lesinurad in the Presence of its Oxidative Degradation Product
摘要： Lesinurad is a novel selective uric acid reabsorption inhibitor which has been recently approved for the treatment of the chronic gout. Four simple mathematical spectrophotometric methods have been developed for the quantitative and selective determination of lesinurad in the presence of its oxidative degradation product. Complete oxidative degradation of lesinurad to its degradation product has been done. The developed methods namely, ratio difference spectrophotometric, first derivative of the ratio spectra, mean centering of the ratio spectra and continuous wavelet transform spectrophotometric methods. These methods have been developed and optimized to resolve the existed overlapping between the zero order UV absorption spectra of lesinurad and its oxidative degradation product. The described spectrophotometric methods have achieved selective determination of lesinurad without any interference from the oxidative degradation product. Also, they have been validated and applied for quantitative analysis of the studied drug in its new pharmaceutical preparation.
关键词： Lesinurad,oxidative degradation,spectrophotometric methods
更新于2025-09-23 15:23:52
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Constructing a novel Zn2SnO4/C/AgBr nanocomposite with extended spectral response and improved photocatalytic performance
摘要： High-ef?cient photocatalyst based on Zn2SnO4/C/AgBr multi-component heterostructure was prepared via a two-step hydrothermal synthesis method followed by chemical deposition process. Morphological studies showed that ultra-?ne AgBr nanoparticles with the size of 3e5 nm were in situ grown on the surface of the carbon layers attached to Zn2SnO4 nanocrystals. UVevis characterization demonstrated that the co-modi?cation of carbon and AgBr contributed to the dramatically improved light absorption ability of Zn2SnO4/C/AgBr nanocomposites. In the multi-component heterostructured photocatalyst, carbon functioning as a charge mediator plays a pivotal role in separating photogenerated electron-hole pairs ef?ciently. Zn2SnO4/C/AgBr photocatalysts exhibited a signi?cant enhancement of visible-light photocatalytic performance toward the photodegradation of rhodamine B (RhB), resulting from the synergistic effect of the intensi?ed visible-light absorption capacity and ef?cient photogenerated electron-hole pairs transfer. In addition, a proposed schematic mechanism for the signi?cant enhancement of photocatalytic performance is as well put forward on the basis of the experimental results.
关键词： Photocatalytic degradation,Visible-light,Heterostructure,Zn2SnO4/C/AgBr
更新于2025-09-23 15:23:52
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AFM-assisted investigation of conformal coatings in electronics
摘要： Purpose – This paper aims to presents a new method of investigation of local properties of conformal coatings utilized in microelectronics. Design/methodology/approach – It is based on atomic force microscopy (AFM) technique supplemented with the ability of local electrical measurements, which apart from topography acquisition allows recording of local impedance spectra, impedance imaging and dc current mapping. Potentialities of the proposed AFM-assisted approach have been demonstrated on commercially available epoxy-coated electronic printed boards in as-received state and after six-year service. Findings – The technique proved to be capable of identi?cation, spatial localization and characterization of conformal coating defects. Practical implications – The proposed approach can be utilized for assessment of protective ?lm state in such demanding ?elds as electronics or electrotechnics where the classical techniques of anticorrosion coatings investigation cannot be employed due to small element dimensions and relatively low coating thickness. Originality/value – The approach adopted by the author is novel in the ?eld of organic coatings investigation.
关键词： Degradation,Corrosion,Electronics,Microscopy,Coatings and linings
更新于2025-09-23 15:23:52
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A triple alkoxo bridged dinuclear cobalt(III) complex mimicking phosphatase and showing ability to degrade organic dye contaminants by photocatalysis
摘要： A dinuclear cobalt(III) complex, [(N3)L1CoIIIL2CoIIIL1] (1), has been synthesized and characterized {H2L1 = 2-((1-hydroxybutan-2-ylimino)methyl)-4-bromophenol and HL2 = 2-amino-1-butanol}. Single crystal X-ray diffraction analysis confirmed its structure. Extended supra-molecular architectures were generated in the complex through weak noncovalent interactions. The energetic features of significant supramolecular interactions have been investigated using DFT calculation and further corroborated with NCI plot index computational tool. The complex has been found to mimic the role of phosphatase enzyme efficiently by transforming 4-nitrophenylphosphate to 4-nitrophenolate at room temperature. The reaction follows Michaelis–Menten enzymatic reaction kinetics with turnover numbers of ~1.4 s-1 in aqueous DMF (98% DMF, v/v) medium. The complex also acts as an efficient photocatalyst for degradation of organic pollutants. Methylene blue (MB), a widely used dye in various industries, was selected as a model pollutant in aqueous media to evaluate the photocatalytic effectiveness of the complex.
关键词： DFT calculation,phosphatase mimicking activity,Photocatalytic degradation of methylene blue (MB),Cobalt(III),Crystal structure
更新于2025-09-23 15:23:52
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Blind image quality assessment with hierarchy: Degradation from local structure to deep semantics
摘要： Though blind image quality assessment (BIQA) is highly desired in perceptual-oriented image processing systems, it is extremely difficult to design a reliable BIQA method. With the help of the prior knowledge, the human visual system (HVS) hierarchically perceives the quality degradation during the visual recognition. Inspired by this, we suggest different levels of distortion generate individual degradations on hierarchical features, and propose to consider the degradations on both low and high level features for quality prediction. By mimicking the orientation selectivity (OS) mechanism in the primary visual cortex, an OS based local structure is designed for low-level visual information representation. At the meantime, the deep residual network, which possesses multiple levels for feature integration, is employed to extract the deep semantics for high-level visual content representation. By fusing the local structure and the deep semantics, a hierarchical feature set is acquired. Next, the correlations between the degradations of image qualities and their corresponding hierarchical feature sets are analyzed, and a novel hierarchical feature degradation (HFD) based BIQA (HFD-BIQA) method is built. Experimental results on the legacy and wild image quality assessment databases demonstrate the prediction accuracy of the proposed HFD-BIQA method, and verify that the HFD-BIQA performs highly consistent with the subjective perception.
关键词： Local structure,Deep semantics,Hierarchical feature degradation,Blind image quality assessment
更新于2025-09-23 15:23:52
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Facile fabrication of phosphorus-doped g-C3N4 exhibiting enhanced visible light photocatalytic degradation performance toward textile dye
摘要： Phosphorus-doped graphitic carbon nitride (P-g-C3N4) was facilely fabricated by in situ thermal copolymerization of urea and triphenylphosphine source materials. The P-g-C3N4 exhibited an enhanced photocatalytic performance than pristine g-C3N4 counterpart for the degradation of rhodamine B and acid blue D-2BR textile dye under visible light irradiation. X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption-desorption isotherms, X-ray photoelectron spectra (XPS), and diffuse reflection spectroscopy (DRS) techniques were used to characterized the structure and property of P-g-C3N4 photocatalyst. The phosphorus doping enhanced visible light harvesting and surface area, but also substantially changed the electronic property of g-C3N4 material that could suppress the recombination of photogenerated charge carriers, and thus improved photocatalytic performance.
关键词： Textile dye,Porous photocatalyst,Visible light,Degradation,Phosphorus-doped g-C3N4
更新于2025-09-23 15:23:52
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KBiO3 as an Effective Visible-Light-Driven Photocatalyst: Stability Improvement by In-situ Constructing KBiO3/BiOX (X = Cl, Br, I) Heterostructure
摘要： Petal-bismuth salt semiconductors are promising as visible-light-driven photocatalysts, but their short service times due to strong oxidation limit their application. In this research, the in-situ construction of a p-n heterojunction, by growing BiOX on a KBiO3 surface, is used as a strategy to improve the performance and stability. Evaluation of the photocatalytic degradation of crystal violet and phenol shows that the KBiO3/BiOX (X = Cl, Br, I) heterostructures exhibit significant improvement in photocatalytic performance and stability compared to KBiO3. The best one, KBiO3/(5.85%)BiOI, shows 98% degradation of crystal violet within 20 min, and of phenol within 1.5 h. No significant performance decay can be detected after repeated use. The development of KBiO3/BiOX heterostructure improves the applicability of KBiO3 as an efficient visible-light-driven photocatalyst.
关键词： Stability,In-situ formation,Heterostructure,Degradation mechanism
更新于2025-09-23 15:23:52