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- 2018
- Carbon nanotubes
- Magnetic focused
- Field emission cathodes
- Travelling wave tubes
- Heat Trap
- outgassing
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- Nanomaterials and Technology
- University of British Columbia
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Damage degree prediction method of CFRP structure based on fiber Bragg grating and epsilon-support vector regression
摘要： The assessment of structural damage is of great significance for ensuring the service safety of carbon fiber reinforced plastics (CFRP) structures. In this paper, the damage degree prediction method of CFRP structure based on fiber Bragg grating and epsilon-support vector regression was studied. The structural dynamic response signals were detected by fiber Bragg grating sensors. Then, the Fourier transform was used to extract the dynamic characteristics of the structure as the damage feature, and the damage feature dimensionality was reduced by using the RReliefF algorithm. On this basis, the damage degree prediction model of CFRP structure based on epsilon-support vector regression was established. Finally, the method proposed in this paper was experimentally verified. The results showed that the epsilon-support vector regression model can accurately predict the damage degree of unknown samples, and the absolute relative error of 27 experiments was less than 10% for 30 testing experiments. This paper provided a feasible method for predicting the damage degree of CFRP structures.
关键词： Frequency response,Carbon fiber reinforced plastics,Epsilon-support vector regression,RReliefF,Damage degree prediction
更新于2025-09-23 15:23:52
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Vertically-grown few-layer MoS2 nanosheets on hierarchical carbon nanocages for pseudocapacitive lithium storage with ultrahigh-rate capability and long-term recyclability
摘要： Molybdenum disulfide (MoS2) are intensively studied anode materials for lithium-ion batteries (LIBs) owing to the high theoretical capacity, but still confront the severe challenges of unsatisfied rate capability and cycle life to date. Herein, few-layer MoS2 nanosheets are vertically grown on the hierarchical carbon nanocages (hCNC) via a facile hydrothermal method, which introduce pseudocapacitive lithium storage owing to the highly-exposed MoS2 basal planes, enhanced conductivity and facilitated electrolyte access arising from the well hybridization with hCNC. As a result, the optimized MoS2/hCNC exhibits the reversible capacity of 1670 mAh g-1 at 0.1 A g-1 after 50 cycles, 621 mAh g-1 at 5.0 A g-1 after 500 cycles, and 196 mAh g-1 at 50 A g-1 after 2,500 cycles, staying at the top level of the MoS2-based anode materials. The specific power and specific energy can reach to 16.1 kW kg-1 electrode and 252.8 Wh kg-1 electrode after 3,000 cycles, respectively, showing the great potential in high-power and long-life LIBs. This finding suggests a promising strategy for exploring advanced anode materials with high reversible capacity, high-rate capability and long-term recyclability.
关键词： pseudocapacitive lithium storage,vertical few-layer MoS2,hierarchical carbon nanocages,long-term recyclability,ultrahigh-rate capability
更新于2025-09-23 15:23:52
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Detection of divalent copper with improved accuracy by dual suppression of electrochemiluminescent recovery
摘要： This work is to construct an electrochemiluminescent (ECL) sensor with improved accuracy for the detection of Cu2+. The improved accuracy is achieved by utilizing a reaction system to realize Cu2+ dose-dependent dual suppression of ECL recovery from gold nanoparticle-graphitic carbon nitride nanosheet nanohybrid (Au-CNNS) film. The ECL sensor shows sensitive response to Cu2+ in the concentration range of 5 nM to 500 nM with an enlarged slope, and high specificity attributed to the high affinity of CNNS-Cu2+ complex and the high catalytic activity of Cu(NH3)6 2+ to decompose H2O2 in the reaction system. The proposed ECL sensor with improved accuracy may prove valuable in future biomedical applications.
关键词： dual suppression,electrochemiluminescent sensor,copper,graphitic carbon nitride nanosheets
更新于2025-09-23 15:23:52
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Effect of Hydration Procedure of Fumed Silica Precursor on the Formation of Luminescent Carbon Centers in SiO <sub/>2</sub> :C Nanocomposites
摘要： The effect of hydration procedure of fumed silica precursor on photoluminescent properties of carbonized silica (SiO2:C) nanocomposite after chemo/thermal treatments is studied. Main structural effect is the formation of chemical bonding of phenyl groups to silica surface via multiple C─Si─O bonding bridges. Synthesized samples demonstrate very broad photoluminescence (PL) bands in near ultraviolet and visible ranges with maximum intensity dependent on temperature of thermal annealing. Two main trends in luminescence properties are: 1) hydration-induced blue shift of PL in comparison with PL of unhydrated series; 2) red shift of PL bands with increasing synthesis temperature regardless hydration procedure. Temperature dependent evolution of light emission bands is discussed in terms of surface carbon nanoclusters formation and aggregation processes. It is assumed that blue shift of PL bands in the hydrated series is associated with the decreased surface mobility of carbon atoms and clusters as a result of increased chemical bonding with silica surface that slows down carbon thermally stimulated clusterization/aggregation processes.
关键词： carbonized nanocomposite material,carbonized fumed silica,phenyltrimethoxysilane,wide-band visible photoluminescence,carbon clusters
更新于2025-09-23 15:23:52
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Multi-fluorescent Cationic Carbon Dots for Solid-state Fingerprinting
摘要： Carbon nanomaterials have been widely explored in bioimaging and biosensing, but their application in forensic science and technology is rare. In this report, we show one-pot synthesis of cationic Carbon Dots (cCDs) and their application in fingerprinting analysis. The cCDs show narrow size distribution (<10 nm), decent quantum yield (c.a. 46%), and a band gap of 2.75 eV. The cCDs exhibit cationic charge and show excitation-dependent multi-fluorescence characteristics. The cCDs show no production of reactive oxygen species and thus are safe to use. Interestingly, they also possess bright liquid as well as solid-state fluorescence. We demonstrate that a well-resolved patterned fingerprint can be obtained within a short time (2-3 min) from different physical surfaces and can be studied using a simple cell phone camera enabling accurate visualization up to third-degree detailing of the fingerprint. Owing to multi-fluorescence characteristics of cCDs, a detailed investigation of the fluorescent patterns was carried out by a three-dimensional multiphoton confocal microscopy. In comparison to traditional methods, the cCDs fluorescence-based fingerprinting shows improvements towards rapid image capture and analysis. Thus, the cCDs form a promising material for rapid fingerprint detection in forensic sciences.
关键词： solid-state,confocal imaging,carbon dots,cell phone,fingerprint
更新于2025-09-23 15:23:52
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Efficient Conversion of CO <sub/>2</sub> to Methane Photocatalyzed by Conductive Black Titania
摘要： One of the major challenges encountered in CO2 utilization is the development of available and cost-efficient catalysts with sufficient activity, selectivity, and stability for the generation of useful methane. Here, conductive black titania, TiO2@x, is found to be efficient in photocatalyzing the reduction of CO2 to CH4. This unique material comprises a crystalline core–amorphous shell structure (TiO2@TiO2@x) with numerous surface oxygen vacancies, which facilitates the adsorption and chemical activation of CO2 molecules. Under full solar irradiation, the optimized 500-TiO2@x material with narrowed band gap and intermediate states below the conduction band tail exhibits a high space-time yield of CH4 of 14.3 mmol g@1 h@1, with 74 % selectivity and excellent photostability. The present findings can make a significant contribution, not only to develop the surface electron-modified black TiO2 catalyst to boost photocatalytic efficiency, but also to establish a really viable and convenient CH4 production process for CO2 conversion and renewable solar energy storage.
关键词： oxygen vacancies,photocatalysis,carbon dioxide chemistry,conductive black titania,methane generation
更新于2025-09-23 15:23:52
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Graphitic Carbon Nitride with Carbon Vacancies for Photocatalytic Degradation of Bisphenol A
摘要： Photocatalysis is intensely employed to remove refractory organic pollutants in water, but suffers from low efficiency due to rapid recombination of photogenerated electrons and holes. Here, carbon vacancies modified g-C3N4 (VC-C3N4) is prepared via a handy two-step calcination method and firstly applied in the photocatalytic removal of bisphenol A (BPA). Compared to pristine g-C3N4, the photocatalytic degradation activity of VC-C3N4 for BPA is largely enhanced, whose kinetic constant (k) of BPA degradation is 1.65 times as that of pristine g-C3N4. The enhanced photocatalytic performance of VC-C3N4 is ascribed to critical role of carbon vacancies: On the one hand, carbon vacancies serve as the reservoir of photogenerated electrons to inhibit the recombination of photogenerated holes and electrons. On the other hand, carbon vacancies as conversion centers transfer trapped photogenerated electrons to absorbed O2 for generation of abundant superoxide radical (?O2-), which takes a dominant effect in the photocatalytic degradation process.
关键词： ?O2- species,bisphenol A,carbon vacancies,g-C3N4,photocatalytic degradation
更新于2025-09-23 15:23:52
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Simultaneous Cr(VI) removal and bisphenol A degradation in a solar-driven photocatalytic fuel cell with dopamine modified carbon felt cathode
摘要： In this work, a carbon felt cathode modified by dopamine (DPA/CF) was explored to enhance the cathodic reduction of Cr(VI) in a two chambers photoelectrochemical system, which was driven by solar light irradiation using BiVO4 photoanode. In the anode chamber, the bisphenol A (BPA) decomposition can be significantly improved by increasing pH to 8. The electron-hole pairs photogenerated on the surface of BiVO4 were efficiently separated by the application of the DPA/CF cathode. At the optimal conditions, 86% of low-concentration BPA was removed within 60 min. In the cathodic chamber, 80% of Cr(VI) was removed at pH of 4. Based on the XPS and electrochemical analyses, it was proposed that the positively-charged groups on the DPA/CF cathode led to the multilayer adsorption of Cr(VI) anions, which enhanced the reduction of Cr(VI) with the electrons generated on the BiVO4. On the other hand, the CeO groups on the DPA/CF electrode also played an important role as electron transfer mediator for Cr(VI) reduction. The prepared DPA/CF cathode associated with BiVO4 photoanode could be a potential application for efficient removal of Cr(VI) and organic pollutants under solar light irritation.
关键词： BiVO4 photoanode,Carbon felt cathode,Dopamine,Cr(VI),Solar photocatalysis,BPA
更新于2025-09-23 15:23:52
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Carbon Nanotube-Supported Cu <sub/>3</sub> P as High-Efficiency and Low-Cost Cocatalysts for Exceptional Semiconductor-Free Photocatalytic H <sub/>2</sub> Evolution
摘要： Developing an inexpensive and high-efficiency hydrogen-production cocatalyst to replace the noble metal Pt remains a big challenge in the fields of sustainable photocatalytic hydrogen evolution. Herein, we report the exploration of a high-efficient binary noble metal free Cu3P-CNT H2-evolution cocatalyst by direct high-temperature phosphatizing of Cu(OH)2-CNT. Impressively, combining the advantages of noble metal free Cu3P and carbon nanotube (CNT), the binary Cu3P-CNT cocatalysts show high-efficient photocatalytic H2 evolution in Eosin Y(EY)-contained semiconductor-free photocatalytic systems. The maximum visible-light H2-generation rate for promising EY-Cu3P-CNT systems was 17.22 mmolg-1h-1. The highest apparent quantum efficiency (AQE) could reach 10.23% at 500 nm. More importantly, we found that the separation of photogenerated electrons and holes in the Eosin Y, the efficiency of electron transfer from EY to the active edge sites of Cu3P, and the electrocatalytic H2-evolution activity of Cu3P, could be simultaneously boosted via readily adding the conductive CNT, thus achieving the significantly improved photocatalytic H2 evolution. This work provides a simple and facile strategy to design highly efficient semiconductor-free photocatalytic proton-reduction systems using high-activity transition metal phosphides (TMPs) and inexpensive carbon nanomaterials.
关键词： Photocatalytic Hydrogen Evolution,noble metal-free Cu3P Co-catalysts,Solar Fuel,Carbon nanotube (CNT),Dye sensitization
更新于2025-09-23 15:23:52
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Highly efficient solar steam generation via mass-produced carbon nanosheet frameworks
摘要： Carbon nanosheet frameworks are synthesized on the gram scale by exploiting the reaction between Mg powder and CS2 vapor. This fluffy carbon nanomaterial coated on fabric shows high performance in solar steam generation. The carbon film has high optical absorption of ~98% in visible and infrared spectrum. When under 1 sun solar-simulated light irradiance (1000 W m-2), the surface temperatures of dry and water-saturated carbon films reach 104 and 45 oC, respectively, indicating good heat localization. As a result, the carbon film under 1 sun illumination shows a high solar-to-vapor efficiency of 93%, which is higher than that of most photothermal conversion materials reported previously. The as-prepared carbon material may pave the way for harvesting solar energy to produce clean water at low cost.
关键词： solar steam generation,Mg thermoreduction,photothermal conversion,carbon nanosheet,vapor-solid reaction
更新于2025-09-23 15:23:52