- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2018
- imgae sensor
- internet of things
- drone
- visible light ID
- Signal-to-Noise Ratio (SNR)
- Infinite Gain Multiple Feedback (IGMF)
- Visible Light Communications (VLC)
- LED
- Trans-Impedance Amplifier (TIA)
- Optoelectronic Information Science and Engineering
- Tohoku University
- University of Northumbria
- University of Huddersfield
-
Control of Spatially Homogeneous Distribution of Heteroatoms to Produce Red TiO2 Photocatalyst for Visible-Light Photocatalytic Water Splitting
摘要： The strong band-to-band absorption of photocatalysts spanning the whole visible light region (400-700 nm) is critically important for solar-driven photocatalysis. Although it is actively and widely used as photocatalyst for various reactions in the past four decades, TiO2 has a very poor ability to capture the whole-spectrum visible light. Here, by controlling the spatially homogeneous distribution of boron and nitrogen heteroatoms in anatase TiO2 microspheres with a predominance of high-energy {001} facets, a strong visible light absorption spectrum with a sharp edge beyond 680 nm is achieved. The red TiO2 with the homogeneous doping of boron and nitrogen obtained shows no increase in defects like Ti3+ that are commonly observed in doped TiO2. More importantly, it has the ability to induce photocatalytic water oxidation to produce oxygen under the irradiation of visible light beyond 550 nm and also photocatalytic reducing water to produce hydrogen under visible light. These results demonstrate the great promise of using the red TiO2 for visible light photocatalytic water splitting and also provide an attractive strategy for realizing the wide-spectrum visible light absorption of wide-bandgap oxide photocatalysts.
关键词： Titanium Dioxide,Photocatalysis,Water Splitting,Homogeneous Doping,Visible Light
更新于2025-09-23 15:21:21
-
Road Segmentation Based on Hybrid Convolutional Network for High-Resolution Visible Remote Sensing Image
摘要： Road segmentation plays an important role in many applications, such as intelligent transportation system and urban planning. Various road segmentation methods have been proposed for visible remote sensing images, especially the popular convolutional neural network-based methods. However, high-accuracy road segmentation from high-resolution visible remote sensing images is still a challenging problem due to complex background and multiscale roads in these images. To handle this problem, a hybrid convolutional network (HCN), fusing multiple subnetworks, is proposed in this letter. The HCN contains a fully convolutional network, a modi?ed U-Net, and a VGG subnetwork; these subnetworks obtain a coarse-grained, a medium-grained, and a ?ne-grained road segmentation map. Moreover, the HCN uses a shallow convolutional subnetwork to fuse these multigrained segmentation maps for ?nal road segmentation. Bene?tting from multigrained segmentation, our HCN shows impressing results in processing both multiscale roads and complex background. Four testing indicators, including pixel accuracy, mean accuracy, mean region intersection over union (IU), and frequency weighted IU, are computed to evaluate the proposed HCN on two testing data sets. Compared with ?ve state-of-the-art road segmentation methods, our HCN has higher segmentation accuracy than them.
关键词： high-resolution visible remote sensing image,Convolutional neural network (CNN),road segmentation
更新于2025-09-23 15:21:21
-
The fabrication of floating Fe/N co-doped titania/diatomite granule catalyst with enhanced photocatalytic efficiency under visible light irradiation
摘要： Powdery photocatalyst has long been studied, yet its several disadvantages such as light-harvesting and recyclability in suspension system are the bottlenecks for practical application. The recent report on floating photocatalyst provided an alternative method to solve the above problem. In this work, TiO2 nanoparticles were co-doped by iron and nitrogen, and then dispersed onto natural porous mineral diatomite via sol-gel method. The composite powder was granulated to produce floating granule catalyst (Fe/N co-doped TiO2/diatomite hybrid granule), denoted as FN-TDHG. Its various physicochemical properties such as light absorbance, crystallinity, surface condition as well as morphology were systematically analyzed. The synergy between Fe and N dopants, as well as diatomite and TiO2 were studied. The photoactivity of FN-TDHG was investigated via the degradation towards tetracycline (TC) solution under visible light irradiation, and then the optimal co-doping amount and granule dosage were determined. The optimal granule catalyst presented its removal rate of TC as 96.5% within 150 min. Moreover, floating FN-TDHG could simply be filtrated from the surface of water matrix, and presented good reusability after 5 repetitions. This photocatalytic granule is hopefully considered suitable to be applied in environmental remediation.
关键词： Fe/N co-doped,Diatomite,Floating,Visible light,Tetracycline
更新于2025-09-23 15:21:21
-
Assembly of graphene on Ag3PO4/AgI for effective degradation of carbamazepine under Visible-light irradiation: Mechanism and degradation pathways
摘要： A highly efficient visible-light-driven photocatalyst Ag3PO4/AgI-Graphene (Ag3PO4/AgI-G) was synthesized through a chemical coprecipitation procedure. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were performed to study the physicochemical structural of the photocatalysts. The photocatalytic activity of the samples was examined by the carbamazepine (CBZ) degradation under artificial visible light and natural sunlight irradiation. Experimental results indicated that the introduction of low mass content of graphene enhanced the photocatalytic performance of Ag3PO4/AgI, and the photocatalytic degradation efficiency of CBZ over Ag3PO4/AgI-3%G (mass ratio of graphene : Ag3PO4/AgI = 3:100) reached 93.06% within 21 min, which was much higher than that over pure Ag3PO4 (26.92%) and Ag3PO4/AgI (74.38%). UV-vis diffuse reflectance spectra, photoluminescence (PL) spectra, transient photocurrent responses and electrochemical impedance spectra (EIS) of the samples were conducted to verify the high photocatalytic performance of the Ag3PO4/AgI-3%G. In addition, possible photocatalytic degradation pathways of CBZ were proposed based on the analysis of transformation products during the reaction. The reactive species trapping experiments and Electron spin resonance (ESR) analysis demonstrated that h+ and ·O2- were the main active oxidant species responsible for CBZ photodegradation. The photocatalytic degradation mechanism of CBZ over Ag3PO4/AgI-3%G under visible light irradiation was schematically proposed. This study not only provides a new technique for the synthesis of Ag3PO4-based photocatalysts with high photocatalytic activity, but also demonstrates that the Ag3PO4/AgI-3%G composite could be a promising photocatalyst for the treatment of waters containing CBZ.
关键词： Photocatalytic degradation,Carbamazepine,Z-scheme,Graphene,Ag3PO4/AgI,Visible light
更新于2025-09-23 15:21:21
-
Visible light active titanates photosensitized by Ti(IV) surface complexes
摘要： For the first time, photosensitization of selected alkaline titanates with surface charge transfer complexes has been proven. Activation of BaTiO3, SrTiO3 and CaTiO3 to visible as well as ultraviolet light has been achieved by impregnation with catechol, salicylic acid and 2,3-naphthalenediol. Simple modification of titanates with organic compounds forming inner-sphere CT complexes with Ti atoms located at the surface of semiconductors resulted in coloration of the materials. Even though acceptor electronic states of titanates are characterized by a higher energy compared with titania (even up to 0.75 eV higher for CaTiO3), complexes formed at titanates’ surface absorb in similar or even broader optical range of visible light. Beside changes in the absorption properties, used modifications also strongly influenced their photoelectrochemical and photocatalytic properties. In contrast to similarly modified titanium dioxide, modified titanates show significantly improved photocatalytic activity not only under visible light but also within ultraviolet range of radiation. Remarkably increased efficiency of photocurrent generation within the UV range of radiation may suggest that apart from observed electron transfer from HOMO of the complex to conduction band (CB) of the semiconductor also indirect photosensitization mechanism through the electron transfer from the excited complexes to the CB of titanates may take place.
关键词： photosensitization,visible light activity,surface complexes,titanates,charge transfer
更新于2025-09-23 15:21:21
-
Validation of spectrophotometric determination of chlorogenic acid in fermentation broth and fruits
摘要： A fast and accurate ultraviolet-visible (UV-vis) spectrophotometric method was established to determine the presence of chlorogenic acid (CGA) according to potassium ferricyanide-Fe (III) detection system. The reaction temperature and pH level greatly influenced the CGA absorption spectrum. Maximum UV-vis absorption wavelength occurred at 790 nm under the optimum conditions (at 25 ℃ and pH 7.0). The results of UV-vis were further assessed by comparing the results with those of high-performance liquid chromatography (HPLC). The proposed method showed a wide linear sensing range of 10.0-800.0 μg mL-1 (R2 = 0.9996) and a high degree of precision (%R.S.D. < 1.50) and recovery (%R.S.D. > 3.39). Results of CGA and HPLC methods correlated well with each other. The proposed accurate, rapid, sensitive, low-cost, and high-throughput method was successfully used to quantify CGA in fermentation broth and fruits (Mango). Therefore, it may be applied for measuring CGA in biological samples.
关键词： Ultraviolet-visible spectrum,Chlorogenic acid,biological samples,high-throughput,HPLC
更新于2025-09-23 15:21:21
-
Constructing 1D CdS nanorod composites with high photocatalytic hydrogen production by introducing the Ni-based cocatalysts
摘要： Various 1D CdS nanorod composites (e.g. NiO/CdS, NiS/CdS and Ni(OH)2/CdS) were constructed by anchoring Ni-based cocatalysts on the surface of CdS nanorods. Photocatalytic reforming of lactic acid in aqueous medium for hydrogen generation using CdS composites was investigated, and Ni(OH)2/CdS sample displayed the best activity. Evidently, Ni(OH)2 cocatalyst can offer a suitable potential position to boost the transfer of photo-generated electrons and much more active sites. Furthermore, the result of LSV curves discloses that the higher photocatalytic activity is due to the smaller onset overpotential, which can accelerate the reduction of protons into H2. This work provides a full comprehension of the mechanism that Ni species cocatalysts improve photocatalytic activity.
关键词： cocatalyst,hydrogen production,CdS nanorods,visible light,Ni-based
更新于2025-09-23 15:21:21
-
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
-
3D graphene aerogels/Sb2WO6 hybrid with enhanced photocatalytic activity under UV- and visible-light irradiation
摘要： A novel ultraviolet (UV)- and visible-light-active 3D graphene aerogels (3DGA)/Sb2WO6 hybrid photocatalyst was prepared by electrostatic self-assembly (ESSA) method. The photocatalytic activity of the 3DGA/Sb2WO6 hybrid was studied by monitoring the change in the concentration of methyl orange (MO) under UV-light and visible-light irradiation. The results demonstrated that the as-prepared hybrid exhibited significantly enhanced efficiency for the photodegradation of MO in comparison with pure Sb2WO6. This was ascribed to the efficient separation of the photogenerated electrons (e–) and holes (h+) with the aid of 3DGA as well as the generated reactive superoxide radical anions (O2(cid:129)–). Moreover, the 3DGA/Sb2WO6 hybrid exhibited high recyclability, because the highly hydrophobic 3DGA in the hybrid was very advantageous to the separation of the hybrid photocatalyst from the MO solutions.
关键词： 3D graphene aerogels,Sb2WO6,Electrostatic self-assembly,Hybrid photocatalyst,Visible-light irradiation
更新于2025-09-23 15:21:21
-
Perfect metamaterial absorber with high fractional bandwidth for solar energy harvesting
摘要： A new perfect metamaterial absorber (PMA) with high fractional bandwidth (FBW) is examined and verified for solar energy harvesting. Solar cells based on perfect metamaterial give a chance to increase the efficiency of the system by intensifying the solar electromagnetic wave that incident on the device. The designed structure is mostly offered in the visible frequency range so as to exploit the solar’s energy efficiently. Parametric investigations with regard to the measurements of the design structure are fulfilled to characterize the absorber. The finite-difference time-domain (FDTD) method-based CST simulator was used to keep the pattern parameters and absorbance analysis. The metamaterial shows almost 99.96% and 99.60% perfect absorption at 523.84 THz and 674.12 THz resonance frequencies. Moreover, absorption’s FBW is studied, and 39.22% FBW is found. The results confirm that the designed PMA can attain very high absorption peak at two modes such as transverse electric (TE) and transverse magnetic (TM) mode. Other than the numerical outcomes demonstrated that the suggested configuration was also polarization angle insensitive. In addition, the change of absorbance of the structure has provided a new kind of sensor applications in these frequency ranges. Therefore, the suggested metamaterial absorber offers perfect absorption for visible frequency ranges and can be used for renewable solar energy harvesting applications.
关键词： solar energy harvesting,polarization angle insensitive,perfect metamaterial absorber,visible frequency range,high fractional bandwidth
更新于2025-09-23 15:21:21