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oe1(光电查) - 科学论文

152 条数据
?? 中文(中国)
  • Indoline and benzothiazole-based squaraine dye-sensitized solar cells containing bis-pendent sulfonate groups: Synthesis, characterization and solar cell performance

    摘要: Two new symmetric squaraine sensitizers (SQTHZ and SQIND) carrying benzothiazole and indoline moieties as strong electron donating groups to inject the electron into the TiO2 nanoparticles were tested as DSSC. The theoretical calculations and absorption results show that the electron density of LUMO of SQTHZ is delocalized in the whole chromophore, leading to strong electronic coupling between SQTHZ sensitizer and the conduction band of TiO2. Furthermore, the presence of long alkyl chain with pendent bis-SO3- groups would inhibit recombination and decrease the dye aggregation. Interestingly, SQTHZ displayed UV-Vis and NIR absorption at a longer wavelength compared to SQIND. This structure feature, as well as optical properties, would lead to improved efficiency of dye-sensitized solar cell with overall better photovoltaic performance (η of 3.31 %, Jsc of 7.65 mA/ cm2, Voc of 0.59, ff of 0.71 and IPCE of 47 % at 674 nm) compared to SQIND.

    关键词: Photoelectrochemical properties,DFT,Dye-sensitized solar cell,Symmetric squaraine dyes

    更新于2025-11-19 16:46:39

  • Rationally Designed Fe2O3/GO/WO3 Z-Scheme Photocatalyst for Enhanced Solar light Photocatalytic Water Remediation

    摘要: A novel ternary Fe2O3/GO/WO3 all-solid-state Z-Scheme photocatalyst was rationally designed. Structural, morphological, optical and electronic properties of the synthesized nanocomposite were investigated by XRD, SEM, TEM, UV-vis Diffuse Reflectance and Raman spectroscopy. The results revealed the successful synthesis of the nanocomposite materials. Uniquely, double absorption edges at 2.0 and 2.3 eV for Fe2O3/WO3 and triple absorption edges at 1.5, 1.8 and 2.1 eV for Fe2O3/GO/WO3 were investigated for the first time. Lower absorption band edges dominated for both Fe2O3/WO3 and Fe2O3/GO/WO3, while higher absorption edges dominated for pure nanomaterials. The enhanced interaction among GO, Fe2O3 and WO3 matrix explained the reduction in the CB energy leading to efficient electron separation and transformation and consequently improving the photocatalytic activity. The visible light photocatalytic performance of Fe2O3/GO/WO3 nanocomposites were evaluated for degradation of methylene blue (MB) and crystal violet (CV) dyes as model water pollutants. The photocatalytic activity for degradation of both dyes was found to be greatly enhanced in the presence of ternary Fe2O3/GO/WO3 nanocomposite as compared to nanocomposite systems of Fe2O3/WO3, WO3/GO and Fe2O3/GO or pure Fe2O3 and WO3 nanomaterials. The enhancement in the photocatalytic performance of ternary Fe2O3/GO/WO3 nanocomposite was proven to be due to the all-solid-state Z-Scheme in which the photogenerated electrons in the CB of photosystem I (WO3) transferred through GO mediator and recombined with the photogenerated holes in the VB of Fe2O3 (photosystem II). So that, the electron-hole pair recombination can be suppressed in both systems. Moreover, the photocatalytic activity of the best Fe2O3/GO/WO3 nanocomposite (FGW 30) has been tested for the degradation of phenol. The results show that 95.4 % of phenol was degraded in 120 minutes. Thus, this study provides an efficient green Z-Scheme photocatalyst for water remediation utilizing solar light.

    关键词: solar light photocatalysis,organic dyes degradation,all-solid-state Z-Scheme,Ternary Fe2O3/GO/WO3,phenol mineralization

    更新于2025-11-14 15:26:12

  • Synthesis of luminescent polymers in the UV light region from dimethacrylate monomer using novel quinoline dyes

    摘要: This study aims at thermal and morphological features, as well as the degree of conversion these luminescent polymers obtained using a dimethacrylate monomer, and quinoline dyes as photoinitiator. The photoinitiators provide a ?uorescent propriety to the ?nal polymer. Thermal properties such as thermal stability, steps of mass loss, and glass transition are obtained by thermogravimetry-differential thermal analysis and derivative thermogravimetric and differential scanning calorimetry. Using the mid-infrared spectroscopy, it is possible to calculate the degree of conversion/rate of polymerization; the data indicate that the quinoline derivatives could be used as photoinitiators in lower concentration (0.1%) resulting in solid rigid polymers with higher conversion (74.24, 71.81, 66.36, and 61.09%). The morphological characteristics of polymers are analyzed by scanning electronic microscopy. Finally, solid ultraviolet–visible (UV–vis) analysis shows a bathochromic shift, due to the stabilization of the molecules in the solid state, compared to liquid UV–vis analysis. ? 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47461.

    关键词: thermal analysis,quinoline dyes,photopolymerization,luminescent polymers,high conversion

    更新于2025-11-14 15:18:02

  • Near-infrared (NIR) surface-enhanced Raman spectroscopy (SERS) study of novel functional phenothiazines for potential use in dye sensitized solar cells (DSSC)

    摘要: Near-infrared (NIR) surface-enhanced Raman spectroscopy (SERS) is used to investigate the interaction between six novel phenothiazine-merocyanine dyes containing the three different functional groups rhodanine, 1,3-indanedione and cyanoacylic acid with plasmonic nanomaterials, to decide if the incorporation of plasmonic nanoparticles could enhance the efficiency of a Gr?tzel-type solar cell. The studies were carried out in the solution state using spherical and rod-shaped gold nanostructures. With KCl induced agglomerated spherical gold nanoparticles, forming SERS hot spots, the results showed low detection limits between 0.1 mmol L?1 for rhodanine containing phenothiazine dyes, because of the formation of Au–S bonds and 3 mmol L?1 for cyanoacrylic acid containing dyes, which formed H-aggregates in the watery dispersion. Results with gold nanorods showed similar trends in the SERS measurements with lower limits of detection, because of a shielding effect from the strongly-bound surfactant. Additional fluorescence studies were carried out to determine if the incorporation of nanostructures leads to fluorescence quenching. Overall we conclude that the addition of gold nanoparticles to rhodanine and 1,3-indanedione containing phenothiazine merocyanine dyes could enhance their performance in Gr?tzel-type solar cells, because of their strong interactions with plasmonic nanoparticles.

    关键词: surface-enhanced Raman spectroscopy,plasmonic nanoparticles,dye sensitized solar cells,phenothiazine-merocyanine dyes,Near-infrared

    更新于2025-11-14 15:16:37

  • Efficient removal of cationic dyes from water by a combined adsorption-photocatalysis process using platinum-doped titanate nanomaterials

    摘要: In this study, two types of titanate nanomaterials (TNMs) including titanate nanosheets (TNS) and titanate nanotubes (TNT) were hydrothermally prepared by controlling reaction times, and then the platinum (Pt)-doped TNMs were fabricated. The photocatalytic performance of as-prepared materials was compared with that of the commercially available TiO2 P25. It was revealed that changing the morphology of TiO2 particles could enhance their adsorption ability and photocatalytic activity for the removal of cationic dyes from water. In particular, all prepared materials displayed greater removal of methylene blue than of P25 through the synergy of adsorption and photocatalysis; however, such an effect was not so pronounced for anionic dyes. For cationic dyes (methylene blue and rhodamine B) and anionic dyes (methyl orange and naphthol blue–black), TNT presented higher photocatalytic activity than TNS. The TNMs, after Pt doping, significantly enhanced photocatalytic activity compared to the pristine ones. Remarkably, 0.5% by weight Pt-doped TNS achieved 100% removal of methylene blue and rhodamine B after 120 min and 140 min of UV irradiation, respectively, outperforming P25, although Pt-doped TNMs showed lower photocatalytic performance than P25 for anionic dyes.

    关键词: Photocatalysis,Cationic dyes,Titanate nanomaterials,Adsorption,Platinum doping

    更新于2025-11-14 15:13:28

  • Handling Electromagnetic Radiation beyond Terahertz using Chromophores to Transition from Visible Light to Petahertz Technology

    摘要: An increase of the operating frequencies of electromagnetic waves leads from the well-established terahertz technology to the visual and reaches petahertz radiation. It is shown that electromagnetic radiation close to petahertz is attractive for technology where knowledge about radio waves can be applied. The dimensions of such radiation are still classically macroscopic; however, molecular components such as resonators were used where quantum mechanics rules have to be considered. Constructions of coupled resonators for energy transfer are as well demonstrated as molecular components for optical metamaterials.

    关键词: Dyes,FRET,Energy transfer,Reflectance,Petahertz,Visible light,Resonators,Metamaterials,Terahertz,Electromagnetic radiation

    更新于2025-09-23 15:23:52

  • Optically switchable bistable guest–host displays in chiral-azobenzene- and dichroic-dye-doped cholesteric liquid crystals

    摘要: Optically switchable bistable guest–host displays in chiral-azobenzene- and dichroic-dye-doped cholesteric liquid crystals (CA-DD-CLCs) are demonstrated. The CA-DD-CLCs in a LC cell treated by homeotropic alignment are initially in stable unwound textures. Given that all LC molecules in unwound textures are oriented perpendicularly to the substrates, the light absorbed by the doped DDs reaches the minimum value, which is considered the transparent state of the proposed CA-DD-CLCs. The CA-DD-CLCs are switched to fingerprint (FP) textures by illumination with ultraviolet (UV) light and can be switched back to unwound textures by illumination with green light. The optical switching between unwound and FP textures is based on the photo-tunable chirality of the doped CA via photoisomerization effect. The light absorbed by the doped DDs in FP textures reaches the maximum value, which is considered the dark state of the CA-DD-CLCs. Moreover, the performances of light absorption from the doped DDs when the CA-DD-CLCs are in unwound and FP textures is independent of the polarization of the incident light. Pattern information can be optically addressed (erased) in CA-DD-CLC cells by illumination with UV (green) light through a suitable photomask. The CA-DD-CLCs can be stabilized in FP textures for several tens of minutes in the dark environment. As such, the power is consumed only for the illumination of specific lights during the switching of CA-DD-CLCs between unwound and FP textures. Moreover, a transparent active matrix organic light-emitting diode (LED) display that is superimposed on top of a CA-DD-CLC cell embedded with a transparent light-guide film with suitable LED light sources for optical switching between unwound and FP textures, is proposed for augmented reality applications.

    关键词: Cholesterics,Absorption,Guest-host display,Liquid crystals,Chiral azobenzene,Dichroic dyes

    更新于2025-09-23 15:23:52

  • Photostable coumarin containing azo dyes with multifunctional property

    摘要: A series five coumarin azo disperse dyes with thiophene bridge are synthesized using diazotized aniline derivatives which are confirmed by FT-IR, 1H NMR, 13C NMR, and CHN analysis. The dyes are applied on polyester and nylon material. The multifunctional properties (lightfastness, washing fastness, sublimation fastness, K/S, UPF, and antimicrobial activity) of the dyed fabric are determined. The dye 3a (-NO2) show red shifted absorption (649 nm) and blocking 95.5-97.4% of UV radiations with 96% antimicrobial property. The geometries of all the azo dyes are optimized using Density Functional Theory (DFT). The Global Reactivity Descriptors (GRD) are evaluated at the same method of theory. The GRD obtained shows a linear relation with lightfastness and UPF ratings. The antimicrobial activity of all synthesized dyes are determined by AATCC 100 test method and it is correlated with the HOMO-LUMO energy band gap.

    关键词: UPF,fastness property,Coumarin-azo dyes,global reactivity descriptors,HOMO-LUMO gap,antimicrobial activity

    更新于2025-09-23 15:23:52

  • Near-Infrared fluorescence chemosensor based on isothiocyanate-aza-BODIPY for cyanide detection in ppb level: Applications in buffer media and living cell imaging

    摘要: A near-infrared chemodosimeter based on an aza-BODIPY dye was designed and synthesized. The sensor contains isothiocyanate groups for cyanide ion sensing. The sensing function was illustrated via the fluorescence changes in near-infrared frequencies as well as chromogenic change which could be easily visualized with a detection limit of 19 ppb. The sensor provides high selectivity to CN? and discriminates other anions such as CH3COO?, HPO4 2?, HSO4 ?, NO3 ?, Cl?, F?, Br?, I?, ClO3 ?, CO3 2?, SO4 2?, and phenylalanine (Phe) in 50% PBS buffer/acetonitrile at physiological pH. The potential of the sensor for CN? detection in both aqueous buffer solutions and living cells imaging were demonstrated.

    关键词: selectivity,cyanide,sensors,aza-BODIPY dyes,near-infrared fluorescence

    更新于2025-09-23 15:23:52

  • Ag/Ag2O/BiNbO4 structure for simultaneous photocatalytic degradation of mixed cationic and anionic dyes

    摘要: In principle, n-type and p-type semiconductors are respectively responsible for photo-catalytic degradation of cationic dyes (e.g., methylene blue) and anionic dyes (e.g., acid red 1), governed by photoelectrons in the former and photo-holes in the later system. Hence, we present a new strategy: design and fabrication of photocatalytic structures to match the redox potentials of mixed basic/acidic dyes as well as the reactive oxygen species (ROS). For the ?rst time Ag/Ag2O/BiNbO4 structure is (1) designed to match the redox potentials of basic/acidic dyes as well as ROS, (2) fabricated using photoreduction to control the Ag/Ag2O/BiNbO4 interfaces, and (3) able to simultaneously degrade 84% methylene blue dye (MB) in 240 min and 88% acid red 1 (AR) in 25 min under LED light irradiation, corresponding to 7 wt% Ag loading. To the best of our knowledge, this is the ?rst photocatalytic degradation study on mixed basic and acidic dyes using a single catalyst. We also tested the new redox potential matching strategy in mixed basic dyes (MB and rhodamine B (RhB)). As expected our experimental results reproduced well our model predictions: in particular, results support our proposed hydroxyl radical (?OH) mechanism, which is initiated by photo-holes. Therefore, this new design strategy, which consists of matching band structures of the photocatalyst with redox potentials of dyes and ROS, has immediate implications to general photocatalytic applications beyond dye degradation and water-splitting.

    关键词: Methylene blue,Nanostructures,Rhodamine B,Photocatalysis,Dye degradation,Acid red,Mixed dyes

    更新于2025-09-23 15:23:52