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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
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Ultraviolet-light-assisted heterogeneous Fenton reaction of Ag-Fe3O4/graphene composites for the degradation of organic dyes
摘要： In this study, Fe3O4/graphene and Ag-Fe3O4/graphene composites with varying content of graphene and Ag were prepared and used as a heterogeneous Fenton catalyst for the degradation of MO and MB under UV-light irradiation. The physicochemical properties of the obtained catalysts were used for the Fenton reaction. In addition, the effects of graphene and Ag content, pH, H2O2 concentration, catalyst loading, and initial MO and MB concentrations on the degradation by the UV-Fenton process were evaluated. Results revealed that the highest removal efficiency of MO and MB is achieved at graphene and Ag concentrations of 10 and 25 wt%, respectively. Furthermore, Ag-Fe3O4/graphene composites were used to assess the degradation of a mixture of MO and MB and other anionic and cationic dyes. Results revealed that Ag-Fe3O4/graphene composites can be used as a broad-spectrum catalyst with good efficiency for the removal of several dye contaminants in water. Moreover, the effect of the addition of ascorbic acid (AA) on dye degradation was investigated. AA accelerated the degradation of organic dyes compared to that without AA. The obtained results revealed that Ag-Fe3O4/graphene composites exhibit stable catalytic activity and reusability after four successive runs.
关键词： Heterogeneous Fenton reaction,Organic dyes,Ag/Fe3O4/graphene
更新于2025-09-23 15:23:52
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Influence of Titanium Dioxide Preparation Method on Photocatalytic Degradation of Organic Dyes
摘要： Titanium catalysts (TiO2) were synthesized by three different methods. Their photocatalytic activity was validated through photodegradation of Reactive Red 45 (RR45) azo dye and Acid Blue 25 (AB25) anthraquinone dye in an aqueous solution under UV irradiation. TiO2 photocatalysts were characterized by FTIR, XRD and SEM. Photosensitivity and TiO2 activity range were characterized by UV/Vis spectroscopy. Photocatalytic validation has been made by way of determining the degree of RR45 and AB25 removal. TOC was determined as a measure of the mineralization of RR45 and AB25 by photocatalysis. The stability of TiO2 catalysts and a possibility of using them in consecutive photocatalysis cycles have also been studied. The results show that the photocatalytic efficiency depends on the crystal structure of TiO2. The size of crystallites depends on synthesis conditions. From the results of photocatalytic efficiency it is concluded that the chemical interaction between a catalyst and a dye strongly depends on the dye chemical structure.
关键词： organic dyes,wastewater treatment,photocatalysis,titanium dioxide
更新于2025-09-23 15:22:29
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Computational design of new organic (Da????a??A) dyes based on benzothiadiazole for photovoltaic applications, especially dye-sensitized solar cells
摘要： A theoretical study on four organic dyes based on bis(4-hexyloxy)triphenylamine as donor and electron acceptor cyanoacrylic acid with a donor–π–acceptor structure (D–π–(D–A–)–A) using DFT/DFT (TD-DFT)/6-31G(d,p) having a difference of π spacer was designed. The theoretical study of the structural, electronic and optical properties of these dyes (D1, D4) suggests that these materials would be excellent sensitizers as a candidate for the production of dye solar cells, due to the efficient photoinduced electron transfer and strong absorption as well as the electronic properties (HOMO, LUMO, Egap) low band gap, The improved light-harvesting efficiency and free energy change of electron injection (ΔGinject), of new designed sensitizers revealed that these materials would be excellent sensitizers. This theoretical designing paves the way for experimentalists to synthesize more efficient sensitizers for solar cells.
关键词： DFT,Dye-sensitized solar cells,Organic dyes,Photovoltaic organic
更新于2025-09-23 15:21:01
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Sustainable Organic Dyes from Winemaking Lees for Photoelectrochemical Dye-Sensitized Solar Cells
摘要： During the last two decades, Dye Sensitized Solar Cells (DSSCs) have received a great deal of attention as a promising, low-cost alternative to conventional silicon photovoltaic devices. Natural dye molecules can be used as a sensitizer for their low cost, good light absorbance, easy preparation process, and biodegradability. In this study, dyes were obtained from wine lees, the last by-product of winemaking process, supplied by a venetian winery (Italy). Polyphenols, like tannins and anthocyanins, which were extracted from winemaking lees, were adsorbed on a nanostructured ordered mesoporous titanium dioxide, previously treated at different temperatures (400–600 °C). Both dyes and titania semiconductor samples were studied with different techniques. The tests were carried out on prototypes to evaluate the cell power and the photocurrent generated under simulated solar light irradiation. The obtained solar energy conversion efficiencies are comparable to those that were reported in literature by using organic dyes extracted from vegetables, fruits, and plants. It is significant that these dyes are largely available and cost effective, since recovered from a waste otherwise to be disposed of, opening up a perspective of feasibility for inexpensive and environmentally friendly dye solar cells to generate green electricity and transforming agri-food waste into a resource.
关键词： circular economy,organic dyes,titania nanoparticles,winemaking lees,DSSCs
更新于2025-09-23 15:21:01
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Preparation and Characterization of CeO2-C60 Nanocomposites and Their Application to Photocatalytic Degradation of Organic Dyes
摘要： Cerium oxide nanoparticles were prepared by the reaction of cerium nitrate hexahydrate and sodium hydroxide. Cetyltrimethyl ammonium bromide (C19H42NBr) was added as a templating agent. The yellow precipitate obtained by the reaction was calcined with fullerene (C60) for 2 h at 700 °C in an electric furnace to synthesize CeO2-C60 nanocomposites. The synthesized samples were characterized by X-ray diffraction, scanning electron microscopy. The photocatalytic activity of the CeO2-C60 nanocomposites for the degradation of organic dyes such as methylene blue, brilliant green, rhodamine B and methyl orange upon irradiation with 254 nm UV light was investigated using a UV-visible spectrophotometer.
关键词： Organic dyes,Photocatalytic activity,Degradation,CeO2-C60 nanocomposites,UV irradiation
更新于2025-09-23 15:21:01
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Near-Infrared Photoluminescence and Electrochemiluminescence from a Remarkably Simple Boron Difluoride Formazanate Dye
摘要： Electrochemiluminescence involves the generation of light via electrochemical reactions and has recently shown utility for single-cell imaging. To further develop this novel imaging platform, it is necessary to produce readily available dyes that photoluminesce and electrochemiluminesce in the near-infrared region to limit absorption by biological tissue. To address this need, we prepared a boron difluoride formazanate dye that exhibits near-infrared photoluminescence in two straightforward synthetic steps. Examination of its solid-state structure suggests that the N-aryl substituents have significant quinoidal character, which narrows the S1-S0 energy gap and leads to near-infrared absorption and photoluminescence. Electrochemical properties were probed using cyclic voltammetry and revealed four electrochemically reversible waves. Electrochemiluminescence properties were examined in the presence of tri-n-propylamine, leading to maximum intensity at 910 nm, at least 85 nm (1132 cm?1) red-shifted compared to all other organic dyes. This work sets the stage for the development of future generations of dyes for emerging applications, including single-cell imaging, that require near-infrared photoluminescence and electrochemiluminescence.
关键词： NIR electrochemiluminescence,Electrochemistry,Formazanate ligands,Organic dyes,NIR photoluminescence
更新于2025-09-23 15:21:01
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Acid(g)/base(g)-controlled reversible ????1/2 of absorption spectrum of a functional dye film
摘要： UV–Vis absorption full width at half maximum (FWHM) plays a significant role not only in describing spectral shapes but also in determining the use of organic dyes for a particular application. For example, organic dyes with a relatively wide absorption FWHM are beneficial with respect to enhancing photon absorption efficiency of solar cells, whereas, for improving color purity in optical filters, narrow FWHM is desirable. Despite such a critical role, studies examining the modulation of absorption FWHM from an organic dye in the solid state are relatively lacking. In this work, we suggest rapid, simple, and effective method to control the absorption FWHM of a squarylium-based dye (SQ) film using an organic solvent vapor. Alternative treatments of base/acid gas to the SQ film (2.0 s for each gas) resulted in reversible absorption FWHM (D FWHM: 121 nm). From the systematic optical and morphology characterizations, it was revealed that changes in FWHM originated from reversible molecular arrangements between monomer-type and H-aggregate-type of SQ by efficient base/acid vapor diffusion into the SQ film. Moreover, the modulation exhibited high fatigue resistance against repeated gas treatments, which secures its practical applications. These results suggest that the proposed simple gas-treatment process in this work is beneficial for the efficient modulation of absorption FWHM of various organic dyes.
关键词： gas treatment,aggregation,organic dyes,full width at half maximum,monomer,absorption spectrum
更新于2025-09-23 15:19:57
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Timea??dependent density functional theory investigations on structural modification in carbazolea??based organic photosensitizers to improve electron injection in dyea??sensitized solar cell
摘要： The time-dependent density functional theory approach, implemented at hybrid-B3LYP, GGA-PBE, and density functional-based tight binding levels of theory, was used to model photoinjection in organic dye/TiO2 quantum dot to explore the prospects of improvement of dye-sensitized solar cell (DSSC). The photosensitizer used in this study consisted of six carbazole-based organic dyes, a cyanoacrylic acid group as an acceptor and an oligothiophene π-bridge spacer. The modifications were made in the dyes by increasing the length of the spacer by adding thiophene and oxadiazole rings at different positions of the donor-acceptor bridge. The structural variations appeared to alter the electronic and optical properties of dyes studied via energy levels and excitation spectra. The UV-Vis spectra calculated for all the dyes in solvents exhibited a red shift in spectral peaks with an increase in the polarity of the solvents. The findings of the study pointed toward the indirect photoinjection of the dye-(TiO2)96 complex for six different dyes. The substitution of the oxadiazole ring at the center and addition of a thiophene ring at the edge of the spacer produced two dyes that exhibited the lowest injection energies of 0.11 and 0.17 eV, along with the regeneration energies of 1.18 and 1.12 eV, respectively. The dyes reported here may have promising applications in photoanode for enhancing the performance of DSSC.
关键词： DSSC,photoinjection,density functional theory,organic dyes
更新于2025-09-23 15:19:57
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NIR organic dyes based on phenazine-cyanine for photoacoustic imaging-guided photothermal therapy
摘要： As non-invasive diagnosis and therapy methods, photoacoustic (PA) imaging and photothermal therapy (PTT) have attracted extensive attention. Herein, two new acceptor–donor–acceptor near-infrared organic phenazine-cyanine dyes PH-1 and PH-2 were reported for photoacoustic imaging-guided photodynamic therapy. In the strong donor phenazine molecule, the electron-withdrawing indole salt unit was introduced for absorption to the near-infrared region. To improve water solubility, the two organic dyes were assembled with human serum albumin (HSA) to form nanoparticles of appropriate sizes, i.e., PH-1@HSA and PH-2@HSA, which showed excellent stability in both weakly acidic and weakly basic environments. Moreover, the results showed that PH-1@HSA and PH-2@HSA nanoparticles can effectively transform luminous energy to thermal energy in vitro and in vivo, and they can be utilized for PA imaging. Importantly, PH-1@HSA can accumulate in mice subcutaneous tumors by enhanced permeability and retention (EPR) and damage cancer tissues effectively.
关键词： NIR organic dyes,phenazine-cyanine,nanoparticles,photoacoustic imaging,photothermal therapy
更新于2025-09-19 17:15:36