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Highly efficient method for oxidation of dissolved hydrogen sulfide in water, utilizing a combination of UVC light and dissolved oxygen
摘要： Hydrogen sul?de is a hazardous contaminant that may appear in well-water and in sewage streams. Here we present a very e?cient way for the removal of H2S from well-water, based on combining UVC light and oxygen. The method was tested with H2S-enriched tap water as well as with natural well water, both of which containing up to 20 mg/L of H2S. A conversion of up to 90% was obtained within a residence time of no more than a few minutes. The quantum e?ciency, de?ned as the ratio between the number of removed H2S molecules to the number of impinging photons, was found to be as high as 70%, depending on conditions. The main product was found to be sulfate, without the appearance of elemental sulfur, i.e. with no major change in turbidity. The absence of sulfur in the outlet stream in of large importance when treating H2S-containing well-water, since it omits the need for posttreatment removal of particles. Results are explained by the excitation of HS- species, following by formation of polysul?de anions that readily react with any formed elemental sulfur, eventually yielding sulfate ions.
关键词： AOP,Water treatment,Sulfate,Hydrogen sul?de,Oxidation
更新于2025-09-23 15:23:52
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Synthesis and annealing process of ultra-large SnS nanosheets for FTO/SnS/CdS/Pt photocathode
摘要： SnS has been widely used in photoelectric devices due to its special band gap of 1.2–1.5 eV. Here, we reported on the fabrication of SnS nanosheets and the effect of synthesis condition together with heat treatment on its physical properties. The obtained band gap of the SnS nanosheets is in the rage of 1.37–1.41 eV. It was found that the photo-current density of a thin film comprised of SnS nanosheets could be enhanced significantly by annealing treatment. The maximum photo-current density of the stack structure of FTO/SnS/CdS/Pt was high as 389.5 μA cm-2, rendering its potential application in high efficiency solar hydrogen production.
关键词： SnS nanosheets,Water splitting,Photoelectrochemical properties
更新于2025-09-23 15:23:52
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Modulated anodization synthesis of Sn-doped iron oxide with enhanced solar water splitting performance
摘要： Modulated anodization synthesis is introduced here for the fabrication of porous Sn-doped iron oxide. Continuous square-wave modulation consisting of highly positive (+50 to +80 V range) and slightly negative potentials (-2 to -10 V range) at 100 Hz allowed the etching anodization of the metallic Fe foil and incorporation of Sn-dopant from the fluoride anion-containing electrolyte, respectively. Compared with the undoped iron oxide, the surface-enriched Sn-dopant (in the form of Sn4+) alleviates the trapping and recombination of surface holes, while enhancing the hole transfer at the surface states. As such, the overpotential for photoelectrochemical (PEC) water oxidation was reduced by 110 mV and photocurrent density doubled. The incorporation of Co-Pi co-catalyst further improved the hole transfer efficiency, resulting in further reduction in overpotential by another 330 mV with respect to the bare Sn-doped iron oxide and significant improvement in photocurrent density at potentials below +1.23 V vs. reversible hydrogen electrode. Lastly, the iron oxide electrodes exhibit highly stable PEC water oxidation with no degradation in activity throughout the 10 h assessment under simulated solar irradiation and Faradaic efficiency of 90%. We envisage that the modulated anodization technique can be conveniently incorporated for a wide range of other dopants in search of efficient solar water splitting electrodes.
关键词： Doping,Hematite,Hydrogen,Photoelectrochemical water splitting,Charge transport
更新于2025-09-23 15:23:52
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Grid Interactive Single Stage Solar Powered Water Pumping System Utilizing Improved Control Technique
摘要： This paper proposes a single stage grid interactive solar powered switched reluctance motor (SRM) driven water pumping system with an efficient control technique. The control of proposed system provides the proficient maximum power point technique (MPPT) tracking and motor drive control with bidirectional power flow between the photovoltaic (PV) array and single phase grid. It has harmonics components elimination, improved dynamic performance and a DC offset rejection capability compared to other control. A PV feed-forward term is also incorporated in developed control to enhance the dynamic performance of the system and to minimize the size of DC link capacitor with improved MPPT performance. The novel scheme of fundamental switching of SRM drive over its maximum operational time (when the grid is present) makes system efficient and reliable. An improved perturb and observe (P&O) based maximum power point tracking (MPPT) algorithm is used in this system to minimize the undesirable losses in a PV array specially under varying insolation levels. The proposed control is tested on a developed prototype and its suitability is authenticated through simulated and test results under various conditions.
关键词： MPPT,Bidirectional Power Flow,Water Pump,Switched Reluctance Motor,VSC,PV Array,Power Quality
更新于2025-09-23 15:23:52
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Achieving high-resolution thermal imagery in low-contrast lake surface waters by aerial remote sensing and image registration
摘要： A two-platform measurement system for realizing airborne thermography of the Lake Surface Water Temperature (LSWT) with ~0.8 m pixel resolution (sub-pixel satellite scale) is presented. It consists of a tethered Balloon Launched Imaging and Monitoring Platform (BLIMP) that records LSWT images and an autonomously operating catamaran (called ZiviCat) that measures in situ surface/near surface temperatures within the image area, thus permitting simultaneous ground-truthing of the BLIMP data. The BLIMP was equipped with an uncooled InfraRed (IR) camera. The ZiviCat was designed to measure along predefined trajectories on a lake. Since LSWT spatial variability in each image is expected to be low, a poor estimation of the common spatial and temporal noise of the IR camera (nonuniformity and shutter-based drift, respectively) leads to errors in the thermal maps obtained. Nonuniformity was corrected by applying a pixelwise two-point linear correction method based on laboratory experiments. A Probability Density Function (PDF) matching in regions of overlap between sequential images was used for the drift correction. A feature matching-based algorithm, combining blob and region detectors, was implemented to create composite thermal images, and a mean value of the overlapped images at each location was considered as a representative value of that pixel in the final map. The results indicate that a high overlapping field of view (~95%) is essential for image fusion and noise reduction over such low-contrast scenes. The in situ temperatures measured by the ZiviCat were then used for the radiometric calibration. This resulted in the generation of LSWT maps at sub-pixel satellite scale resolution that revealed spatial LSWT variability, organized in narrow streaks hundreds of meters long and coherent patches of different size, with unprecedented detail.
关键词： Lake surface water temperature,Uncooled infrared camera,Image registration,Lake Geneva,Thermal imagery,Aerial remote sensing
更新于2025-09-23 15:23:52
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Atomic layer deposition of cobalt(II) oxide thin films from Co(BTSA) <sub/>2</sub> (THF) and H <sub/>2</sub> O
摘要： In this work, we have studied the applicability of Co(BTSA)2(THF) [BTSA = bis(trimethylsilyl)amido] (THF = tetrahydrofuran) in atomic layer deposition (ALD) of cobalt oxide thin films. When adducted with THF, the resulting Co(BTSA)2(THF) showed good volatility and could be evaporated at 55 °C, which enabled film deposition in the temperature range of 75–250 °C. Water was used as the coreactant, which led to the formation of Co(II) oxide films. The saturative growth mode characteristic to ALD was confirmed with respect to both precursors at deposition temperatures of 100 and 200 °C. According to grazing incidence x-ray diffraction measurements, the films contain both cubic rock salt and hexagonal wurtzite phases of CoO. X-ray photoelectron spectroscopy measurements confirmed that the primary oxidation state of cobalt in the films is +2. The film composition was analyzed using time-of-flight elastic recoil detection analysis, which revealed the main impurities in the films to be H and Si. The Si impurities originate from the BTSA ligand and increased with increasing deposition temperature, which indicates that Co(BTSA)2(THF) is best suited for low-temperature deposition. To gain insight into the surface chemistry of the deposition process, an in situ reaction mechanism study was conducted using quadrupole mass spectroscopy and quartz crystal microbalance techniques. Based on the in situ experiments, it can be concluded that film growth occurs via a ligand exchange mechanism.
关键词： atomic layer deposition,reaction mechanism,thin films,Co(BTSA)2(THF),cobalt oxide,water
更新于2025-09-23 15:23:52
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A promising family of fluorescent water-soluble aza-BODIPY dyes for in vivo molecular imaging
摘要： A new family of water-soluble and bioconjugatable aza-BODIPY fluorophores was designed and synthesized using a boron-functionalization strategy. These dissymmetric bis-ammonium aza-BODIPY dyes present optimal properties for a fluorescent probe, i.e. they are highly water-soluble, very stable in physiological medium, they do not aggregate in PBS, possess high quantum yield and finally they can be easily bioconjugated to antibodies. Preliminary in vitro and in vivo studies were performed for one of these fluorophores to image PD-L1 (Programmed Death-Ligand 1), highlighting the high potential of these new probes for future in vivo optical imaging studies.
关键词： molecular Imaging,Fluorescent probes,boron functionalization,aza-BODIPY,Water-soluble fluorophores
更新于2025-09-23 15:23:52
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Magnetite-Supported Gold Nanostars for the Uptake and SERS Detection of Tetracycline
摘要： Magnetite nanoparticles (MNPs) decorated with gold nanostars (AuNSs) have been prepared by using a seed growth method without the addition of surfactants or colloidal stabilizers. The hybrid nanomaterials were investigated as adsorbents for the uptake of tetracycline (TC) from aqueous solutions and subsequent detection using surface-enhanced Raman scattering (SERS). Several parameters were investigated in order to optimize the performance of these hybrid platforms on the uptake and SERS detection of TC, including variable pH values and the effect of contact time on the removal of TC. The spatial distribution of TC and AuNS on the hybrid composites was accomplished by coupling SERS analysis with Raman imaging studies, allowing also for the determination of the detection limit for TC when dissolved in ultrapure water (10 nM) and in more complex aqueous matrices (1 μM). Attempts were also made to investigate the adsorption modes of the TC molecules at the surface of the metal NPs by taking into account the enhancement of the Raman bands in these different matrices.
关键词： SERS,antibiotics,magnetite nanoparticles,Au nanostars,water pollutants
更新于2025-09-23 15:23:52
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Unprecedented Multicolor Photoluminescence from Hyperbranched Poly(amino ester)s
摘要： A novel kind of water-soluble fluorescent hyperbranched poly(amino ester) (PAE) is prepared through a one-pot polycondensation reaction of citric acid (CA) and N-methyldiethanolamine (NMDEA). The PAE exhibits enhanced and red-shift fluorescence with increasing solution concentration, showing distinct aggregation-induced emission character. Interestingly, the resulting PAE exhibits tunable photoluminescence from blue, cyan, and green to red irradiated by altering the excitation wavelengths. Such unique emission of non-conjugated PAE is attributed to the clustering of ester and tertiary amine groups derived from PAE self-assembly aggregates. Moreover, the fluorescence of PAE is very sensitive to Fe3+ ions. The facile preparation and unique optical features make PAE potentially useful in numerous applications such as multicolor cellular imaging, Fe3+ ions probe, and light-emitting diodes.
关键词： aggregation-induced emission,poly(amino ester)s,water-soluble polymers,hyperbranched,fluorescence
更新于2025-09-23 15:23:52
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Elucidation of the structural and charge separation properties of titanium-doped hematite films deposited by electrospray method for photoelectrochemical water oxidation
摘要： Elemental doping is considered to be an effective strategy to improve the photoelectrochemical (PEC) activity of hematite (a-Fe2O3) as a photoanode for water splitting, but the precise function(s) of the dopant remains unclear. In this study, we report on the structural and charge separation properties of titanium-doped hematite (Ti doped Fe2O3) films prepared by a simple electrospray technique for PEC water oxidation. The effect of Ti doping on the structure, morphology, light absorption, and electrical and photoelectrochemical properties was investigated on a-Fe2O3 films. SEM images revealed a reduction in particle sizes for 2% Ti doped a-Fe2O3, while an increase in particle size was observed for higher Ti content. XRD confirmed the presence of a-Fe2O3 without any impurity or other phases. From XPS spectra, the incorporation of Ti was confirmed in the form of Ti4+ as predominant species while no impurities from the substrate were detected. When the Ti doped Fe2O3 (2% Ti) film was used as a photoanode in a PEC cell, it delivered the best performance with a maximum photocurrent density of 1.09 mA cm-2 (at 1.8 V vs. RHE and under standard 1 sun illumination conditions (AM 1.5 G, 100 mW cm-2)), which is 2 times higher than that of the un-doped a-Fe2O3 (0.51 mA cm-2). The photoelectrode also showed a superior incident photon to current efficiency (IPCE) as compared to an un-doped a-Fe2O3. This enhancement in performance was attributed to the better charge separation and transport properties of a-Fe2O3 due to Ti doping, as revealed by an electrochemical impedance spectroscopy (EIS) analysis.
关键词： Electrospray deposition,PEC,a-Fe2O3,Ti doping,Water splitting
更新于2025-09-23 15:23:52