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Binary composites WO3/g-C3N4 in porous morphology: Facile construction, characterization, and reinforced visible light photocatalytic activity
摘要： Various WO3/g-C3N4 binary composites were constructed by a facile one-step calcination procedure and then systematically analyzed for chemophysical properties. Interestingly, these resultant composites showed porous morphology in combination with some tubular structures, where both components were closely contacted to generate heterojunction structures. Accordingly, these composites possessed reinforced visible-light absorption capability and enlarged specific surface areas in texture. These microstructural, morphological, and electronic merits ensured the strengthened photocatalytic performance toward degradation of rhodamine B (RhB) and methylene blue (MB) under visible light irradiation. In addition, on base of reactive species entrapping experiments and analytical results, a probable photocatalysis mechanism was speculated as a “Z-scheme” manner instead of conventional Type II path.
关键词： WO3,Photocatalytic degradation,Mechanism,Porous morphology,Binary composites,g-C3N4
更新于2025-11-14 17:04:02
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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
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A micro-structural corrosion mechanism on the thermal degradation of BaMgAl10O17: Eu2+ phosphor
摘要： The thermal degradation is a vital issue that restricting luminous efficiency and service life of BaMgAl10O17: Eu2+phosphor for chromogenic and illuminating fields. The effects of heat-treatment temperature on the luminescence properties and micro-structure of BAM were researched to accurately elucidate the thermal degradation mechanism. Some pieces of evidence for micro-structural corrosion were detected according to the results of PL, TL, XPS and IR. With the heat-treatment temperature increasing, a decrease of blue-emitting intensity and new red-emitting peaks revealed thermal degradation and activator oxidation. The XPS results showed the surface chemical composition changes and the micro-structure adjustment. The defects elimination detected by TL could be responsible for this micro-structural corrosion. IR results further confirmed the changes on bond forms. These were direct evidence and specific forms for the micro-structural corrosion due to the thermal degradation. Based on the relationship between micro-structural corrosion and luminescence properties, a micro-structural corrosion mechanism was given for the thermal degradation of BAM phosphor. The thermal degradation was caused in parallel by the micro-structure corrosion and the activated ion (Eu2+) oxidation.
关键词： Micro-structural corrosion,Thermal degradation mechanism,BaMgAl10O17:Eu2+,Heat-treatment
更新于2025-09-23 15:22:29
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Degradation of methylparaben using BiOI-hydrogel composites activated peroxymonosulfate under visible light irradiation
摘要： A novel hydrogel photocatalyst (p(HEA-APTM)-BiOI) was synthesized by irradiation polymerization and chemical precipitation method, while employed as peroxymonosulfate (PMS) activator to enhance methylparaben (MP) degradation. The structure, morphology and physicochemical properties of the prepared p(HEA-APTM)-BiOI were characterized by XRD, XPS, SEM, TEM, FTIR and BET. The experimental results revealed that the MP catalytic degradation by p(HEA-APTM)-BiOI activated PMS can achieve the best performance under the visible light irradiation. In addition, the parameters including the molar radio of [PMS]/[MP], initial pH, Cl- and HCO3- were also investigated in detail. It was worth noting that p(HEA-APTM)-BiOI also effectively eliminated MP in the absence of visible light. Based on the quenching experiment, 1O2, h+ and ?O2- were determined as the dominant active species contributing to the catalytic oxidation process in the p(HEA-APTM)-BiOI/PMS/Vis system, and the possible degradation mechanism was also elaborated. Eventually, the possible pathways of MP degradation were deduced from several intermediates identified by HPLC-MS.
关键词： Methylparaben,peroxymonosulfate,degradation mechanism,visible light,BiOI-hydrogel
更新于2025-09-23 15:21:21
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Accelerated photocatalytic degradation of organic pollutants over carbonate-rich lanthanum-substituted zinc spinel ferrite assembled reduced graphene oxide by ultraviolet (UV)-activated persulfate
摘要： Carbonate-rich lanthanum-substituted zinc spinel ferrite assembled reduced graphene oxide nanohybrids (LaZF@rGO) were simply synthesized using a simple hydrothermal-induced precipitation process. The synthesized photocatalytic material, LaZF@rGO, showed excellent photocatalytic performance in the decolorization and mineralization of rhodamine B under ultraviolet (UV) irradiation with the aid of peroxydisulfate. The photocatalytic activity of the optimized carbonate-rich lanthanum-substituted zinc spinel ferrite assembled reduced graphene oxide nanohybrids was approximately two times higher than that of zinc spinel ferrite assembled reduced graphene oxide, suggesting the critical role of lanthanum in assisting the peroxydisulfate degradation of rhodamine B. The prepared photocatalyst was successfully utilized in the removal of a wide spectrum of selected organic contaminants such as charged dyes and pharmaceutical and personal care products under UV irradiation. The obtained “green” photocatalyst has a great potential for practical applications, since it can be regenerated and reused at least four times with negligible loss of photocatalytic activity and with insignificant leaching of potentially hazardous toxic elements (e.g., lanthanum and zinc) to the environment.
关键词： Lanthanum-substituted zinc spinel ferrite,Degradation mechanism,Photocatalysis,Persulfate activation
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Degradation Mechanism Identified for the Fullerene and Non-fullerene based Organic Solar Cells under Ambient Condition
摘要： Solution-processed organic solar cells (OSCs) have becoming a promising photovoltaic technology for a low-cost electricity generation. However, poor stability of OSCs is still a severe problem need to be understood and solved for future application. In this work, we conducted an air stability study for both fullerene and non-fullerene based OSCs. As a result, the degradation mechanism was found different for these two types of OSCs. The Urbach energy determined the EQE measurement indicates that the air-degradation in fullerene based OSCs is mainly ascribed to its increased energetic disorder. Differently, the photoluminescence (PL) measurement implied that the air-degradation in non-fullerene based OSCs mainly results from the degraded charge dissociation and energy transfer ability. Therefore, different stability improving strategy will be needed for fullerene and non-fullerene based OSCs in future.
关键词： non-fullerene,air stability,degradation mechanism,fullerene,organic solar cells
更新于2025-09-23 15:19:57
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Microwave discharge electrodeless mercury lamp (Hg-MDEL): an energetic, mechanistic and kinetic approach to the degradation of Prozac?
摘要： A photochemical reactor composed of an Hg-MDEL was applied in photodegradation studies of fluoxetine (Prozac?). The reactor exhibited to be an efficient hydroxyl radical generation system, since constant of formation of OH? formation is optimized through the adjustment of this parameter. An increase in the initial hydroxycoumarin (4HC) and 7-hydroxycoumarin (7HC) solutions resulted in the kinetics constant value, the mean kinetic constant was k = 10.64 ± 1.25 min -1 and R 2 = 0.943 ± 0.131. The Prozac? photodegradation studies showed that the application of the pseudo-first-order applied for degradation of Prozac?, the study of variation of the microwave power allowed a concentration of Prozac from 33 to 134 μmol L-1 resulted in a 21% decrease in the kinetic significant increase in the rate of degradation of the Prozac?, indicating that the hydroxyl radical the OH? quantification studies conducted with coumarin (COU), 4- kOH = 3.14 ± 0.18 min-1. When the Hg-MDEL reactor was 100% for its highest concentration (134 μmol L-1) at the time of 0.75 min. As for the solution of Prozac? 101 μmol L-1, the energy consumption was 6 kWh g-1, achieving a removal of 99%. formation of hydroxyl radicals, a high degradation rate of organic compounds (Prozac?, COU influence exerted by the transformation products. In general, the total removal of Prozac? was kinetics should be limited to the time of up to 0.50 min for the respective system, due to the Finally, the photochemical system presented in this work demonstrates a high efficiency in the and 7HC) and low energy consumption.
关键词： hydroxyl radical,direct photolysis,fluoxetine,pharmaceuticals,and kinetics,degradation mechanism
更新于2025-09-19 17:15:36
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Construction of morphology-controlled nonmetal 2D/3D homojunction towards enhancing photocatalytic activity and mechanism insight
摘要： Highlights ? A novel nonmetal 2D/3D g-C3N4 homojunction was constructed via the facile surface in-situ polymerization process. ? The nonmetal 2D/3D g-C3N4 homojunction displayed the dramatically enhanced photocatalytic performance for degrading TC-HCl. ? The improved transfer and separation efficiency of charge carriers resulted from synergetic effect of 2D-3D structural coupling and energy band controlling. ? This work develops a feasible exemplificative strategy for fabricating new morphology-controlled at the interface between structural units owing to the matching chemical and electronic structures, nevertheless it still is difficult to fabricate the morphology-controlled nonmetal homojunction. Herein, a nonmetal 2D/3D homojunction is constructed via the facile surface Constructing homojunction is more favorable to transfer and separation of charge carriers nonmetal homojunctions to improve photocatalytic activity microspheres, mainly attributing to the improved transfer and separation efficiency of charge homojunction displays the dramatically enhanced photocatalytic performance for degrading tetracycline hydrochloride (TC-HCl) compared with single 2D CN nanosheets and 3D CC carriers resulted from synergetic effect of 2D-3D structural coupling and energy band controlling. Moreover, the important degradation pathway, intermediate products and surface of 2D g-C3N4 (2D CN) nanosheets. The obtained nonmetal 2D/3D CN/CC in-situ polymerization process, where 3D g-C3N4 (3D CC) microspheres tightly anchor on the photocatalytic mechanism are investigated in detail. This work develops a feasible exemplificative strategy for fabricating new morphology-controlled nonmetal homojunction to improve photocatalytic activity.
关键词： Degradation mechanism,TC-HCl,Nonmetal homojunction,g-C3N4,Morphology-controlled
更新于2025-09-19 17:13:59
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Role of Carbon Nanotubes to Enhance the Long-Term Stability of Dye-Sensitized Solar Cells
摘要： Improving the long-term stability of Dye-sensitized solar cells (DSSCs) is a critical challenge which affects both their technical viability and future large-scale commercialization. Here, we investigate the role of multi-wall carbon nanotubes (MWCNTs) in improving the long-term stability of DSSCs by comparing the performance of two series of devices made of (i) bare nanocrystalline TiO2 and (ii) MWCNTs-TiO2 composite anode, exposed to continuous simulated sunlight, indoor and ultraviolet (UV) light irradiation. The DSSCs based on the composite anode showed approximately three times longer stability compared to the standard device. To understand the degradation mechanisms that underpin these changes in device performance, both devices were characterized using various techniques. The results indicate that the MWCNTs can act as a conductive support, reinforcing the TiO2 nanoparticles matrix and offering a directional path to the photo-injected electrons, which enhances electron lifetime and reduces the carrier recombination rate. UV stability measurements demonstrated that MWCNTs can partially absorb and act as a blocking agent for UV light, thereby preventing degradation. The Raman spectra showed that dye desorption was decreased by the addition of MWCNTs. Our results provide a fundamental understanding of photoanode degradation mechanisms under illumination and offer a simple, low-cost and large-area scalable approach to fabricate long-term stable solar energy conversion devices.
关键词： Multi-walled carbon nanotubes,Long-term stability,Dye-sensitized solar cells,hybrid composite,degradation mechanism
更新于2025-09-19 17:13:59
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Degradation Mechanism Detection in Photovoltaic Backsheets by Fully Convolutional Neural Network
摘要： Materials and devices age with time. Material aging and degradation has important implications for lifetime performance of materials and systems. While consensus exists that materials should be studied and designed for degradation, materials inspection during operation is typically performed manually by technicians. the manual inspection makes studies prone to errors and uncertainties due to human subjectivity. in this work, we focus on automating the process of degradation mechanism detection through the use of a fully convolutional deep neural network architecture (f-cnn). We demonstrate that f-cnn architecture allows for automated inspection of cracks in polymer backsheets from photovoltaic (pV) modules. the developed f-cnn architecture enabled an end-to-end semantic inspection of the pV module backsheets by applying a contracting path of convolutional blocks (encoders) followed by an expansive path of decoding blocks (decoders). first, the hierarchy of contextual features is learned from the input images by encoders. next, these features are reconstructed to the pixel-level prediction of the input by decoders. the structure of the encoder and the decoder networks are thoroughly investigated for the multi-class pixel-level degradation type prediction for pV module backsheets. the developed f-cnn framework is validated by reporting degradation type prediction accuracy for the pixel level prediction at the level of 92.8%.
关键词： photovoltaic backsheets,automated inspection,degradation mechanism,fully convolutional neural network,semantic segmentation
更新于2025-09-12 10:27:22