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Dual-functional graphite/TiO2 (G/ TiO2) nanocomposites were successfully prepared by physical pressure to form tablet construction and adding the voltage density to examine as an adsorption-photoelectrocatalytic (PEC) degradation against methyl orange (MO) organic dye. The mass variation of TiO2 pristine, graphite, and G/ TiO2 (1:1 and 1:2) were studied to observe the enhanced adsorption-PEC degradation. The results show that the G/ TiO2 nanocomposites has high distribution particles on the graphite surface. In addition, the XRD pattern was shown the TiO2 rutile and little anatase phase contained in TiO2-P25, and graphite has an especially characteristic peak on 2 thetas 26.5° and 54.5°. The adsorption-PEC degradation test was examined, where the 1:1 mass variation of G/ TiO2 substrate displays more superior adsorption-PEC degradation activity in a range time of 10-30 min. The hindrance of graphite saturation occurs with increasing times evaluation which concluded that the graphite was unable to absorb the wastewater. On the other hand, TiO2 displays high-PEC performance for degrading MO dye. The adsorption-PEC degradation activity of G/TiO2 nanocomposites in the treatment of MO dye indicates that it has prospective application in developing highly wastewater treatment for removing organic dyes in nature. [ABSTRACT FROM AUTHOR]

Over the last two centuries, new approaches to the synthesis of heterocycles have had a profound effect on organic and inorganic chemistry. Nanocatalysts play a significant role in the various filled of science. We present a unique and environmentally friendly method for the one-pot biosynthesis of zinc sulfide nanoparticlesin this research. XRD, FT-IR, EDX, TEM, and investigations described very stable and hexagonal phase ZnS. Nanoparticles are made from leaves extracted from BurmanniaCoelestis tender pods. The current approach for producing ZnS NPs is both efficient and cost-effective. The powder XRD pattern revealed that ZnS NPs formed a hexagonal tight packing configuration with an average crystallite size of 35.6 nm. Simple-shaped ZnS NPs with an average diameter of 60-80 nm are visible in the TEM image. The as-prepared ZnSNPs are good sonocatalysts for the degradation of organic dyes and the production of 2-benzimidazole derivatives. [ABSTRACT FROM AUTHOR]

The performance of solar cells is improved by usingluminescent solar concentrators(LSC) devices. The devices consist of organic fluorescent pigments embedded in a matrix material. Pigment molecules diffuse in an appropriate manner to absorb sunlight and re-emit it by a process called fluorescence. Eight organic pigments and a PVA polymer matrix were selected for synthesizing the LSC. The tested dyes are Thionin, Cuomarin-151, Fluorescin complexone, Eiosin yellow, Rhodamin – B, Crystal violet, Nil blue, and Alizarengelb - GG Dyes. The selecting criteria are that all these pigments give emissions in the response area of the Si solar cell. All pigments showed good results and were able to raise the efficiency of the applied Silicon solar cell, but in varying proportions. The efficiency of the bare Si solar cell was 11.33%, We got the best results when using Thionin dye, where the efficiency value increased to17.32% while using Alizaringleb-GG gave the lowest result(7.15%). Many cascade LSCs werepreparedwith different thicknesses, and the efficiency improvement was observed in the range of 34.87% as the upper value and 12.27% as the lower one. [ABSTRACT FROM AUTHOR]

In this paper, Pure and Er doped SnO2 (Er = 1%, 3%, 5% and 7%) nanoparticles have been synthesized by sol-gel method to investigate the degradation of harmful Rose bengal dye. Undoped and erbium-doped SnO2 nanoparticles formed a tetragonal rutile structure, as shown by X-ray diffraction. Oxygen vacancy concentration has been found to increase with an increase in dopant incorporation, according to photoluminescence analysis. Furthermore, the band gap was reduced up to 5% Er (Eg = 3.37 eV) in comparison to that of non-substituted SnO2 (Eg = 3.74 eV), with the creation of vacancy defects being the main cause. The photocatalytic results indicate that 96.94% Rose bengal dye have been degraded by Er 5% within 60 min under UV light irradiation, indicating Er 5% doped SnO2 is the most suitable catalyst to degrade industrial waste (organic dye) on a large scale. [ABSTRACT FROM AUTHOR]

In this paper, Zn0.5Ni0.5Fe2O4 nanoparticles were prepared by the Co-Precipitation method for photocatalytic application. The X-ray diffraction analysisrevealed a single-phase crystalline naturewith a crystallite size of 13.80 nm. The SEM analysis shows analmost spherical morphology of the sample. The band gap is determined with the help of Tauc's plot and found to be 1.98 eV for Zn0.5Ni0.5Fe2O4. The synthesized nanoparticles are used as photocatalysts for Rose Bengal dye degradation and were found to be 77.43% efficient in 50 minutes. Hence, the synthesized Zn0.5Ni0.5Fe2O4 nanoparticles have excellent application as a catalyst in organic dye degradation. [ABSTRACT FROM AUTHOR]

Malachite green (MG) dye is a toxic cationic, azo soluble organic dye blamed for grievous health complications and aquatic pollution. The present study assesses the potential of cabbage waste powder (CWP) in the adsorptive removal of malachite green dye from aqueous solution. Batch experiments were designed to evaluate the impact of dye concentration, temperature. pH, adsorbent dose, particle size and contact time in dye removal. Adsorption equilibrium was realized within 80 minutes with adsorption efficiency of 92.5% at pH 8. The percentage dye removal improved with rise in time of contact, adsorbent dose and surface area to volume ratio but declined with rise in temperature. FTIR analysis established numerous functional groups of lignocellulosic compounds on adsorbent, which greatly influenced dye removal. The sorption kinetics obeyed pseudo-second order kinetic model while the equilibrium data followed Freundlich isotherm model. These results prove that the cabbage waste powder is indeed a worthwhile, overabundant and environmentally safe biosorbent for adsorptive removal of organic dyes from textile wastewaters. [ABSTRACT FROM AUTHOR]

One of the most promising alternatives from the point of view technology is to fabrication of solar cells sensitized with dyes natural as they have been shown to have a relatively high efficiency at a low cost of production. In particular, the motivation of the present research work is based in addition to the above mentioned, in the constant search for new materials and processes for the manufacture of solar cells. We are particularly interested in developing methods ecological and that are friendly with the environment. The present work reports the results obtained from the study of the manufacture and characterization of solar cells type DSSC (Dye Sensitized Solar Cells) with TiO2 sensitized with organic dyes obtained from cactus fruit and hibiscus flower. The electrodes were constructed with TiO2, through the deposit of Dr. Blade, while the conductive glass counter electrodes were coated with graphite of a common pencil and commercial iodine was used as electrolyte. The cactus fruit red ink extraction was carried out by extraction alcoholic using sodium carbonate, while hibiscus ink is obtained by maceration. Optical characterization of both dyes was carried out by UV-Vis spectroscopy. Adhesive tapes were used in the construction of the TiO2 electrodes to obtain different thicknesses and find an optimal thickness to have good efficiencies. The results of the characterizations showed that the sensitized cells with better efficiency. [ABSTRACT FROM AUTHOR]

This study included the synthesis of CuCo2O4-MgO spinel composite, which was prepared by the co-precipitation method from their aqueous nitrates as starting materials, the prepared spinel composite was characterized by using XRD, FTIR, UV. Visible, AFM, and FESEM spectroscopies. Particles size of the prepared adsorbent surface was found ranging from 25 to 75 nm. As it has been applied in removing toxic organic dyes from textile industry wastewater. This study showed the best optimal conditions for removal of dye was: 30 minutes of adsorption time 0.005g of the surface adsorbent, 50 mg.L−1 of dye concentration, the best pH value of dye mixture solution equal to 5, at a temperature of 298K, gave a high removal of 97%, also found that the negative free energy (ΔG) and heat of reaction (ΔH) values, indicating that the reaction is spontaneous and exothermic, while the entropy value (ΔS) was positive, indicate that the occurrence of disturbance of water molecules around the dyes. [ABSTRACT FROM AUTHOR]

The Organic dyes are appealing optical substances in many applications in bio photonic and photonic. The present research includes study Non-linear optical peculiarities of Rhodamine 6G in disaccorded concentrations (0.03m M, 0.05 m M,0.1mM),a The nonlinear calculated included using (Z-Scan) technique. The measurements were achieved with using (CW) lasers at wavelengths (405nm, 473 nm, 532nm, 650nm) and with laser power of (1.49 mw, 4.35mw, 11, 56 mw, 5mw) respectively. The results showed that Nonlinear refraction index coefficient and nonlinear absorption coefficients increased with increasing the concentration of samples, the nonlinear refractive index n2 of Rhodamine 6G dye dissolved in Ethanol were detect that based upon the wave length of laser with concentration of sample. [ABSTRACT FROM AUTHOR]

In this study, modelling and simulation of batch adsorption of organic dye of methylene blue (MB) by using modified metal-organic framework-5 (MOF-5) were investigated. The film-pore diffusion model was developed based on external mass transfer coefficient (kf) and pore diffusion coefficient (Dp) that governs the mass transfer process in batch organic dye adsorption. These two parameters were estimated using a program written in Matlab software by corresponding the simulation data with the experimental data obtained from previous study. Based on the findings, the estimated mass transfer coefficient and pore diffusion coefficient were 66.8 m/s and 2.15×10-7 m2/s, respectively. Applying the estimated parameters, the MB adsorptions by using modified MOF-5 were investigated to observe the effects of MOF-5 modification, initial dye concentration, temperature, and the dosage of adsorbent. It was found that the adsorption capacity of modified MOF-5 (H6P2W18O62/MOF-5) was higher than pure MOF-5. Besides, the lower initial MB dye concentration, higher temperature, and lower adsorbent dosage result in higher dye adsorption capacity. [ABSTRACT FROM AUTHOR]

The remarkable progress of organic dye based on donor-π-acceptor concepts has been extensively studied to enhance carrier mobility, electrical performance and can perform function at an optimum level in advanced electrochemical energy devices. In this study, new organic additive for solid polymer electrolyte (SPE) has been successfully synthesized by incorporating fused aromatic azomethine (-CH=N-) dye in carboxy methylcellulose (CMC) with ammonium thiocyanate (NH4SCN) based electrolyte. Assessment of the synthesized additive has been physico-chemically characterized via Fourier transform infrared (FT-IR), UV-visible (UV-vis), 1D Nuclear Magnetic Resonance (NMR) and thermogravimetric (TGA) analysis. Besides, DFT calculation revealed that the value of HOMO-LUMO gap exhibits semiconductor properties with the activation energy of 3.135 eV. The investigation of their capability as organic additive SPE has been discovered by incorporating CMC-NH4Cl via solution-casting technique. The structural analysis was conducted to study the effect of the atomic structure in correlation towards ionic and conductivity of newly develop SPE. The ionic conductivity of SPEs system has been measured using Impedance Spectroscopy with various weight percentage (wt%) of additive. The highest conductivity of SPEs at 303K was approximately ∼10-3 Scm−1 at 0.6 wt%. As a result, the incorporation of fused aromatic azomethine into the SPE has a great potential to be used for electrochemical device application. [ABSTRACT FROM AUTHOR]

The improvement of Information Communication and Technology (ICT) affects the demand for electricity. Dye-Sensitized Solar Cells (DSSC) is an alternative for electricity supply. Research on organic dyes and capacitive touchscreen layers has been interesting recently. In conventional, Capacitive touchscreen layers use an Indium Tin Oxide (ITO) as a channel. Replacing the ITO substrate with an organic material for capacitive touchscreen coating is a promising approach. In addition to low cost, organic dyes have an efficiency of up to 0.86%. Compared to the efficiency of conventional DSSC (2-3%), this value is not bad. Research on organic dye is also in line with the concept of sustainability and environment friendly. In this work, organic dyes were extracted from red dragon fruit (Hylocereus costaricensis). Extraction of red dragon fruit was carried out by maceration method with distilled water and the addition of citric acid. The TiO2 layer was deposition by slip casting method. The results showed that red dragon fruit extract contained anthocyanins from phytochemical screening tests and UV-Vis spectrophotometers. [ABSTRACT FROM AUTHOR]

Dye-Sensitized Solar Cell (DSSC) is a cheap alternative energy option to overcome the world energy crisis. DSSC fabrication and characterization have been done as an organic dye. DSSC is a photo-electrochemical-based solar cell where organic color substances are used as sunlight absorbers and inorganic semiconductors as a place for the separation of electrical charges. DSSC can convert sunlight into electrical energy by using electrolytes as charge transfer. The study was conducted with dye from Red Dragon fruit skin and meat. The variations of immersion time of semiconductor TiO2 in the dye for 12 hours, 24 hours, and 48 hours were also carried out. Characterization was conducted in low light 20 Watt LED light source. The test results obtained a higher and stable voltage and current in DSSC with dye from red dragon fruit in Ethanol compared to DSSC with dye red dragon fruit skin in Ethanol. Based on low-light characterization, we found the best Photo Conversion Energy (PCE) using red dragon fruit skin as dye were obtained at 48 hours immersion with a current of 1 mA, voltage of 2.5 mV, and efficiency of 0.0093%. The best PCE using red dragon fruit meat as the dye was obtained at 48 hours immersion with a current of 4.7 mA, voltage of 8 mV, and efficiency of 0.2394%. [ABSTRACT FROM AUTHOR]

The non-linear optical characteristics of organic laser dyes (Acriflavine,Orcein, and Azur-B) dissolved in Ethanol solvent with concentration (10−5M) were investigated in this study. The UV-VIS spectrophotometer measures the spectra' linear optical characteristics. It was determined the nonlinear optical characteristics by using the Z-Scan method, which represents a very sensitive approach for obtaining two essential optical phenomena: nonlinear refractive index and nonlinear absorption coefficient, in two different situations (close aperture) and (open aperture). The results indicate (Acriflavine,Orcein, and Azur-B) is a promising material to be used in photonic and nonlinear optical devices.An optical power limiter uses this promising medium for a range of optoelectronic applications. [ABSTRACT FROM AUTHOR]

Hydrotalcite as one of the advanced materials is applied in wide range of aspects like adsorption. This research aims to study the capability of the hydrotalcite like compound Mg-Al-CO3 material to remove the organic dye, namely, congo red and methylene blue in water through adsorption. Prior to the adsorption process, hydrotalcite like compound Mg-Al-CO3 was calcined within temperature ranges of 300-750°C. The adsorption process was carried out by batch method with variations in calcination temperature of the hydrotalcite material and variations in contacting time. The performance effectiveness of hydrotalcite was evaluated through the adsorption percentages based on the absorbance measurement data using the UV-Vis instrument. The results showed excellent hydrotalcite's capability of removing both organic dyes. Hydrotalcite calcined at 600°C was able to remove 94% of the organic dyes within 30 minutes. [ABSTRACT FROM AUTHOR]

In this paper, we have developed a technique for the synthesis of an aggregatively stable sol containing nanoparticles of both manganese dioxide and cobalt oxide. The paper considers the several colloidal chemical properties of sol and properties of the final layers. X-ray fluorescence analysis confirmed the presence of Mn, Co, and O on the membrane surface. Analysis of the X-ray diffraction diagram showed that the particles of the synthesized sol consist of manganese and cobalt compounds: MnO2 and Co3O4. Samples of deposited membranes were tested, in which the membrane showed the presence of catalytic activity in the reaction of dye oxidation. Due to atomic absorption spectroscopy, the leaching of each of the metals in the reaction mixture after the reaction is insignificant. [ABSTRACT FROM AUTHOR]

TiO2−coated glass has been successfully prepared for practical water treatment application under UV-light irradiation. This work demonstrated the immobilized TiO2 powder on glass support using the dip-and spray coating method. The number of coating processes was varied to studies their effect on photocatalytic efficiency. The annealed process at high temperature was conducted to improve the adhesion of TiO2 powder to the glass substrates. Surface observation of the coating TiO2 showed that the dip-coating method has a better result than the spray coating method. All the glass surfaces can be covered by TiO2 perfectly, and this process did not affect the photocatalytic activity. Almost 100% of 4 ppm Rhodamine B could be decomposed by immobilized TiO2. The current research is potentially used as a standard method to immobilize TiO2 on the glass substrate on a larger scale in the future. Accordingly, separating the process between TiO2 and liquid-based solution after the photocatalytic process is more straightforward. [ABSTRACT FROM AUTHOR]

Because of the dyes' potential toxicity and visibility in surface waters, the treatment of hazardous organic dyes has piqued the attention of many people. The heterogeneous photocatalysis using titanium (TiO2), the most promising technology to decolorize the chlorazol black BH dye. This photoreaction was followed to the pseudo-first-order with low activation energy (Ea), which equal to -24.202 kJ mol−1. Furthermore, the thermodynamic parameters were determined utilization the Arrhenius, Eyring-Polanyi, and Gibbs equations proved that this photoreaction was exothermic, with less random and non-spontaneous reaction. In addition, the optimum conditions were controlled with applied the artificial UV-A and found to be 500 mg TiO2 dose, initial pH value at 5.04, and 283.15 K for 100 minutes. [ABSTRACT FROM AUTHOR]

Fluorine doped Tin Oxide (FTO) was used as the substrate for the synthesis of Multi-Walled Carbon Nanotubes/ Zinc Oxide nanorods composites. The first composite was a layer-by-layer sample of Multi-Walled Carbon Nanotubes/ Zinc Oxide nanorods and the second was a mixed sample of Multi-Walled Carbon Nanotubes/ Zinc Oxide nanorods. Characterisation techniques including XRD, FE-SEM and UV-Visible spectroscopy were performed on both the composites to investigate the diffraction peaks, morphology and band gap energy, respectively. Dye degradation and Photoeletrochemical (PEC) performance of both the composites were studied and the results proved that the photocatalytic activity and the photoelectrochemical performance were improved by the incorporation of MWCNT with ZnO nanorods. The highest dye degradation of 64.44% and 39.57% under UV and AM1.5G illumination and the highest photocurrent density of 1.5x10−4 A/cm2 and 8.0x10−5A/cm2 under UV and AM1.5G illumination were achieved by the MWCNT/ZnO layer-by-layer sample. This makes MWCNT/ZnO nanorods layer-by-layer sample a promising candidate for the removal of organic dyes from waste waters and for the production of Hydrogen as a source of sustainable energy by using the abundant light energy for water splitting. [ABSTRACT FROM AUTHOR]

In the current work, the optical nonlinearities and optical limiting behaviors for mixture of two organic laser dyes: Rhoda mine B (RB) and Methyl violet (10B) dissolved in ethanol solvent at concentration (10−6) M, have been measured utilizing Z-Scan setup. The measurement was completed using continuous wave(CW) diode pump solid state laser at wavelength(457 nm) and power (84mW).The closed-case Z-scans of all samples give self-defocousing phenomena. The consequences of the open-case of all samples give two photon absorbtion. Non-linear optical properties of mixture dye is larger than those for single dyes. The results revealed that all samples can be a good candidate for optoelectronic and photonic applications. [ABSTRACT FROM AUTHOR]

In the present work, non-linear optical properties of azure A organic laser dye, dissolved in ethanol solvent with concentration (10−4 M) have been studied. The linear optical properties measured by UV-VIS spectrophotometer device after investigated by Fourier translation infrared (FTIR).The nonlinear optical properties measured using a highly sensitive method known as Z-Scan technique, in two cases (close aperture) and (open aperture) for obtain two important optical phenomena: nonlinear refractive index and nonlinear absorption coefficient. The result indicates that the sample of this dye show a negative nonlinear refractive index and two photon absorption (2PA). The results indicate (Azure A) is a promising material to be used in photonic and nonlinear optical devices. It can be used as a potential medium for various optoelectronic applications including that in optical power limiting. [ABSTRACT FROM AUTHOR]

The reaction of sodium silicate with 3-(chloropropyl)triethoxysilane (CPTES) and tin chloride (SnCl2) was carried out at room temperature and pressure. The template (CPTES) was removed by calcinations at 500 οC and give solid tin onto silica (labeled as RHASn). The tetragonal structure of SnO2 confirms by XRD patterns onto the silica surface. A reduced carbon percentage with the presence of Sn onto silica after calcinations was deducted by elemental analysis. FT-IR recorded a vibration of Si-O-Sn; while UV-VIS-DR spectrum reflects that the Sn species in tetrahedral environments or hexacoordinated polymeric Sn-O-Sn type species could be formed. RHASn had 87.34 m2 gm−1 as a specific surface area and the pore size ranged between 2-5 nm falls in the microporous range. The RHASn prepared was applied as an adsorbent to remove the brilliant blue (BB) and methylene blue (MB) dyes from aqueous solutions. Box-Behnken design (BBD) was used for investigating the significant variables that have a direct relationship with the BB and MB dyes removal i.e. RHASn dose, initial pH, temperature, and time. The obtained results showed a high removal percentage for BB and MB dyes, reached up 97.2 % and 98.1 %, respectively. This work indicates that the ability of RHASn to be an effective adsorbent in treating wastewater containing organic dyes. [ABSTRACT FROM AUTHOR]

The object of this research activity was the treatment of water contaminated by the organic dye Blue Patent V, through the use of carbon nanotubes. To optimize the adsorption process, a system containing simultaneously carbon nanotubes and titanium oxide was also studied, followed by periods of exposure to sunlight for programmed times. As is known, titanium oxide is an important photo catalytic agent. In the latter case, the aim was to verify whether titanium oxide, in a first phase, could photodegrade the dye molecules into smaller components, which could subsequently be more easily adsorbed by carbon nanotubes. The system containing only carbon nanotubes proved highly efficient in reducing the concentration of dye, while the system containing carbon nanotubes and titanium oxide reported a lowering of the abatement efficiency compared to the system containing only nanotubes. [ABSTRACT FROM AUTHOR]

The degradation of organic dyes using semiconductor nanoparticles (NPS) has been a hot topic of research in the research field for decades. Materials bandgap, crystallinity, stability, high surface to volume ratio, etc., are the factors affecting the dye degradation mechanism. A high surface area will create more active sites, which will increase the reaction speed during the degradation process. In this work, co-metal substituted ZnS (Znx(MnCo)0.5(1-x)S), and CoFe - ZnS composites were used as catalysts for the photodegradation process since the ZnS is a wide bandgap semiconductor material with the most negligible toxicity and high surface to volume ratio. Here authors studied structural and optical characterization of the synthesized material followed by dye degradation analysis using a UV-Vis spectrophotometer. Mainly Methylene blue, Rhodamine-B, and Sunset yellow dyes were used for the study, and the same was irradiated in visible light with the help of an as-prepared catalyst. Finally, the degradation rate of all three dyes was determined and compared. [ABSTRACT FROM AUTHOR]

A single-photon source is an essential tool for the emerging field of quantum technologies. Ideally, it should be spectrally compatible with other photonic systems while providing a high flux of narrow-band photons. The single organic dye molecule dibenzanthantherene (DBATT) embedded into a n-tetradecane Spol'skii matrix under cryogenic conditions possesses the given characteristics, thus constitutes a prominent single-photon source. Nevertheless, the implementation of such a single-photon source requires an elaborate experimental setup involving a cryostat with a confocal microscope for the effective collection of the molecule's emission. Another approach is to use a single emitter coupled to an optical fiber. This approach has the potential to transfer a single-photon source from a proof-of-principle type of setup to a scalable "plug and play" device. Here we present the alignment-free fiber-coupled organic molecule single-photon source cooled down to cryogenic temperatures using a transport dewar as a cryostat. [ABSTRACT FROM AUTHOR]

The luminescence investigations of organic sensitizing dyes Rhodamine 6G and Erithrosin adsorbed on silver stearate were performed. A strong overlap of the absorption and luminescence spectra was detected for both dyes. It was determined that the luminescence quantum yield of Rhodamine 6G adsorbed on silver stearate is 0.6. [ABSTRACT FROM AUTHOR]

We are designed eight novel organic dyes with D-π-A. These colors comprise of electron-benefactor (quercetin) and electron-acceptor/securing (cyanoacrylic) associated by the n-conjugated linker as an electron spacer. By utilizing the thickness useful hypothesis (DFT) and time-subordinate DFT (TD-DFT) techniques with B3LYP utilitarian and 6-31G(d,p) premise set to examine some natural atoms by considering the retention range, the electronic states change, electronical properties, and the scope of the ingestion range. The improvement of the quercetin color is finished by the diverse linker expansion and same electron-acceptor where the assimilation gets higher than that of the first color and furthermore the vitality progress becomes lower in the DSSCs that utilization TiO_2 as a gatherer charge. Was concentrate additionally the impact of Ti(OH)4 on these colors.The vitality holes of these planned colors (inside 2.25-3.35 eV) are littler than that of quercetin color. Our outcomes are valuable for a superior comprehension of the structure rule of quercetin based natural colors for future DSSDs. [ABSTRACT FROM AUTHOR]

The present work introduces a microwave assisted one pot green synthesis of gold nanoparticles using fresh leaves of a medicinal plant, Biophytumsensitivumas both the reducing and capping agent. The green synthesized gold nanoparticles are characterized using UV-vis, FT-IR, XRD, HRTEM and EDX analysis. The synthesized stable gold nanoparticles show a characteristic surface plasmon resonance peak at 534 nm in UV-vis. X-ray diffraction study confirms the crystalline nature of nanoparticles. The transmission electron microscopic analysis shows that the average size of nanoparticles is 37.92 nm.The catalytic properties of the synthesised green gold nanoparticles is depicted in the degradation of organic azo dye, congo red by sodium borohydride.The degradation reaction follows pseudo first order kinetics. [ABSTRACT FROM AUTHOR]

Various types of organic dyes are discharged by textile/batik industry daily. These are the problematic issues for water treatment system based on semiconductor photocatalysts as various types of organic dyes could degrade differently due to different in molecular nature. In this study, the photocatalytic activity of TiO2 particles in degradation of various types of organic dyes, i.e. methylene blue (MB), rhodamine B (RhB) and bromocresol green (BG) dyes, under visible light and UV light irradiation were systematically studied. The crystal structure and morphology of TiO2 particles were analyzed by X-ray Diffraction Spectroscopy and Field-emission Scanning Electron Microscope, respectively. The average diameter of Rutile-TiO2 was 92 ± 39 nm. The degradation of organic dyes was monitored from its maximum absorption peak measured by ultra violet-visible spectrophotometer. Under UV light irradiation, high degradation efficiencies of dyes were observed and followed the order of: RhB > MB > BG, indicating that the dyes were mineralized by photogenerated hydroxyl free radicals and/or superoxide free radicals. Under visible light irradiation, the photodegradation efficiencies followed the order of: MB > RhB > BG. As compared to UV light, the degradation of organic dyes were different in visible light which relied on the electrons ejected from dye molecules upon absorbing light energy. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cells are an attractive third generation photovoltaic emerging technology. These solar cells are currently alternative to the conventional inorganic silicon-based cells because of the advantages, such as low-cost materials and simple fabrication processes. Some challenges remain in the field of research, such as long-term stability and operation lifetime. Third-generation solar technologies include solar cells sensitized by dye materials (DSSCs), quantum dots (QDs) and perovskites. Among of them, DSSCs are the longest-standing third-generation solar technology. Currently, DSSCs using inorganic metal complex dye(e.g.RU), synthetic/natural organic dyes in different type of electrolyte. Recently, the two systems have achieved similar record efficiencies approaching 12% and other exceeding 13%. In this review, we will highlight the recent research on sensitizers for DSSCs, including ruthenium complexes, metal-free organic dyes, and natural dyes with their corresponding efficiencies. Also, the latest approaches to enhance the performance of natural dyes have been discussed. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C3N4) was synthesized by facile pyrolysis method. XRD pattern confirmed the single phase and hexagonal crystal structure of g-C3N4. FE-SEM studies confirmed the formation of flaky and sheet-like morphology. This hexagonal structured g-C3N4 has good wettability property due to the presence of lone pair of electron in the nitrogen atom. Consequently, the g-C3N4 nanostructure can provide more number of active sites for catalytic reactions. Therefore, the g-C3N4 nanosheets were implied as visible light active photocatalyst for the degradation of organic dye pollutants. From the results, it is evident that g-C3N4 exhibits superior photocatalytic activity towards crystal violet, acridine orange and rhodamine B. Hence, it is proposed that g-C3N4 can be an active photocatalyst towards diverse group of organic dyes. [ABSTRACT FROM AUTHOR]

In this paper, influence of varying annealing temperature on size, band gap, magnetic properties and photocatalytic activity of 8% Zn doped α-Fe2O3 in comparison to pure α-Fe2O3 has been described. A facile and effective sol gel method was used to synthesize these nanoparticles and subsequently annealed at 500 °C, 700 °C and 900 °C for 2 hours. XRD measurement revealed the formation of rhombohedral phase without any impurities. The crystallite size is found to increase while band gap reduces with an increase in annealing temperature. It has been found that Zn doped α- Fe2O3 has higher photocatalytic activity at 900 °C, indicating this temperature is most appropriate annealing temperature for degrading industrial waste (organic dye) at large scale. [ABSTRACT FROM AUTHOR]

In this work, bismuth oxide (Bi2O3) photocatalyst was prepared using nitrates of bismuth through a single step microwave method. These Bi2O3 photocatalysts were analysed by using various techniques such as XRD, Raman, UV-Vis spectroscopy and time resolved photoluminescence (TRPL) life time measurements. The Bi2O3 photocatalyst was formed with tetragonal structure in the as-prepared form and it was structurally transformed into a monoclinic phase with appropriate heat-treatment at 550 ᵒC. This was noticed as a phase transformation from β-phase (tetragonal) to α-phase (monoclinic structure) which has been confirmed by XRD and Raman spectroscopy analysis. The synthesized Bi2O3 photocatalyst with monoclinic phase was tested for the photocatalytic degradation of Rhodamine B (Rh-B) under Sun light irradiation and the results are discussed in this paper. [ABSTRACT FROM AUTHOR]

Contact Glow Discharge Electrolysis is a process of electrolysis with DC current to form electric sparks due to the electrons that undergo plasma excitation in the electrolyzed solution. Plasma electrolysis produce hydroxyl radicals, a powerful oxidant, with greater amount than other advanced oxidation method. This method is used to degrade much weight organic compounds such as dye. This research aims to evaluate the degradation of dye waste Remazol Brilliant Red (RBR) using Contact Glow Discharge Electrolysis method with air injection. The injection of air can increase hydroxyl radicals production and can decrease energy consumption. The condition used are dye concentration is 100 mg/L, NaCl 0,03 M, in addition of air bubbles and FeSO4 30mg/L applied power 450 W, and anode depth 2 cm. Dye degradation is measured by its absorbances with Spectrophotometer UV-Vis. The result of this research show that the efficiency of dye degradation in addition of microbubbles is increased with percentage of degradation was 99,63% in 30 minutes, final concentration of dye is 0,51 mg/L, COD 70.34 mg/L and specific energy is 3,129.395 kJ/mmol. [ABSTRACT FROM AUTHOR]

The absorption and photoluminescence spectra of fluorescein 27 (F27) in presence of graphene and graphene quantum dots (GQD) have been investigated quantitatively. The fluorescence intensity of F27-graphene hybrid system is reduced drastically as compared to free F27. In contrast, the GQDs enhance the luminescence by a factor of 1.5. The fluorescence quenching of F27-graphene hybrid system suggests a strong charge transfer (CT) from F27 to graphene. On the other hand, the fluorescence enhancement in case of GQD takes place due to the vdW type complex formation between GQD and F27. It is concluded here that while the F27-graphene, the CT complex is non-fluorescent in nature but with GQD a weak fluorescent complex formation takes place with a possibility of facilitating the energy transfer from the former to latter. [ABSTRACT FROM AUTHOR]

Present scenario requires methods for treatment of industrially waste water polluted with hazardous chemicals and dyes. This work reports efficient utilization of nano-ceramic ‘hydroxyapatite’ for degradation of Indigo Carmine dye present in waste water under ultra violet light illumination. The photo-catalytic experiment is carried out via artificially polluting water with Indigo Carmine dye at three different dye concentration (5, 10, and 20 mg/L) in presence of hydroxyapatite nano-powder (25 mg). After 180 min ultra violet light illumination, almost 63, 61 and 43 % dye degradation is observed in above dye solution. Treatment of such dye polluted water is necessary for making it usable water for society and for the development of sustainable ecosystem. [ABSTRACT FROM AUTHOR]

In this paper, a photocatalytic evaluation was carried out for several synthetized samples of glass foam coated with different amounts of TiO2 and WO3, respectively in order to investigate their capacity to remove Rhodamine B (RhB) from aqueous solution, under simulated solar irradiation. As the organic dyes are considered a major source of pollution to the environment, RhB was selected for this study as a dye model of organic dyes pollutants. The morphology of the glass foams impregnated with TiO2 and WO3 was examined by 3D laser scanning microscopy and SEM microscopy. Additionally, physical and chemical properties of the samples were determined using FT-IR and Raman spectroscopy. The artificial solar light was provided by a solar simulator Sol 2A and 20 ml RhB aqueous solution with initial concentration of 0.0015 g L-1 was used for each sample for the photocatalytic experiments. The degradation of RhB was determined by monitoring the absorbance of RhB solution by UV-VIS spectroscopy for 2 hours, at every 10 minutes, subsequent to the adsorption-desorption equilibrium reached in dark conditions. Enhanced photocatalytic properties were obtained for the samples of glass foams coated with TiO2, with a maximum degradation of RhB of 92%, whereas the degradation of RhB in the presence of WO3 fixed on glass foams reached a maximum value of 58%. [ABSTRACT FROM AUTHOR]

To improve the efficiency of the DSSC circuit, light absorption from organic dyes must reach the maximum visible and near infrared spectrum values. This research examined improvement of efficiency DSSC transparent by optimizing of natural dyes hybrid synthetic dye (DN-F01). Compotition of natural dyes in this research used anthocyanin (black rice and black sticky rice). Anthocyanin dyes and DN-F01 with optimized choice of agents indicated that improved photovoltaic impacts contrasted with single individual dye sensitization and increased the absorption of solar light and allowed utilization of the photon energy more efficienly. With using spin coating method, FTO glass with TiO2 as working electrode and opposite electrode used FTO glass with platinum paste. To determine the efficiency of DSSC for characterization of electrical properties using Keithley I-V meter. The highest efficiency of the DSSC circuit is obtained from a combination of Black Rice Dye and 1% DN-F01 which is equal to efficiency (η) reached 1.065 % with an open circuit voltage (Voc) of 378 mV, short circuit current density (Isc) of 1.235 mA with fill factor (FF) of 0.656. [ABSTRACT FROM AUTHOR]

In this experimental research, the possibility of using a well-known titanium silicate, called ETS-4, for the purification of water contaminated by an organic dye was tested. The purpose of the present research was to exploit, under certain conditions, both the adsorbent and the photocatalytic capacities of this material for the purification of water contaminated by the Blu Patent V dye. This dye is mainly used in the textile industry and it is often present in its waste water. A further intent was to identify a low cost method and for this reason, only sunlight was used to promote photocatalytic reactions. In particular, systems consisting of predetermined quantities of ETS-4 phase and dye solution were exposed for variable times to sunlight. Each system, after the predetermined time of exposure, was filtered and the resulting liquid phase was analyzed by UV analysis to measure the variations in concentration of the dye, while the solid phase was analyzed by thermal analysis (TG; DTG). The ETS-4 phase showed significant photodegradative capacities on the analyzed dye that increase in the presence of hydrogen peroxide. All this allows us to hypothesize its use, in decontamination tanks containing waste water contaminated by the dye and exposed for a short period to sunlight. [ABSTRACT FROM AUTHOR]

Density functional theory (DFT) and time dependent density functional theory (TDDFT) calculations were performed for evaluating the photophysical and photochemical properties of a sequence of carbazole based metal-free organic dyes modified using different π-conjugation spacer units, such as thiopine, pyrrole, furan, thiazole and isoxazole. Moreover, the modified dyes were subjected to investigation towards their non-linear optical (NLO) features. The results revealed that dipole moment (μ), static polarizability (α), anisotropic polarizability (Δα) and hyperpolarizability (first order (β) and second order (γ)) of modified dyes are considerably enhanced as a consequence of changing the spacer unit. Likewise, light harvesting efficiency and oscillator strength of the modified dyes are enhanced upon wavelength of absorption is red-shifted by influence of spacer moieties. We believe that our calculations provide a more profound physical perception on structural property relationship for carbazole based dyes and give a hint to create potential sensitizers for opto-electronic and dye-sensitized solar cell applications. [ABSTRACT FROM AUTHOR]

Colloidal quantum dots (CQDs) are coming up as appealing platform, as exciting class of fluorescent probes for optical imaging, because of their tunable and unique optical properties, high stability and ability to target affected tissue, based on their surface functionalization compared to small molecules of organic dyes. More empathetically, it has been observed that the current dyes lack the signal penetration needed for optimal performance, the tissue specification, and stability in metabolic systems and photo bleaching resistivity properties. Thus, semiconducting QDs represent an exciting class of luminescent materials with favourable fluorescent properties like narrow emission band; efficient stokes shift and long fluorescent lifetime. Most specifically, tunable fluorescence ranging from UV-blue to the mid infrared emission to maintain high resolution for deeper imaging can be achieved by altering the size, size distribution and crystal structure of the QDs. These potential properties make QDs suitable as direct substitutes for the existing dyes. From the last 5-6 years, the application of fluorescent QDs, as probes for biological domain are emerging as smart bio-medical imaging, bio-tagging and drug delivery agents leading to a highly promising technique as fluorescent based techniques are very sensitive. However, decision of making QDs as the future heir of the present day drug associates/dyes, is still perplexed as their toxicity is a matter of great concern. Toxicity has become an integral part of QDs mainly due to a) nonsurface passivation, b) oxidative degradation, c) poor biocompatibility and d) choosing of nonbiocompatible capping agents. Therefore efforts are going on to neutralize these threats during the synthesis part only, by surface functionalizing the QDs with better biocompatibility and cytofriendlyness. Since, these QDs are self-sufficient to heal any bacterial growth when bacteria are in touch with them, keeping in view of having tremendous potential application as tagging, imaging and antibacterial agents in biological systems, the present work reports the preparation, characterization and biocompatibility of semiconducting QDs with surface modifications to establish them as efficient fluorescent probes in health and medical sector. [ABSTRACT FROM AUTHOR]

Sonocatalytic degradation of Methyl Orange in a 40 kHz, 124 W ultrasonic bath was carried out in the presence of zinc oxide (ZnO) catalyst. The catalysts were subjected to heat treatment from 200 °C to 800 °C for 2 hours and were characterised by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. XRD confirmed that no phase change occurred even though calcined up to 800 °C whereas SEM showed that catalysts started to undergo aggregation when the heat treatment temperature was raised to 600 °C. The effect of initial dye concentration, catalyst loading, pH and hydrogen peroxide (H2O2) concentration on the sonocatalytic activity were carried out at 2.5 mg/L to 12.5 mg/L, 0.2 g/L to 1.0 g/L, pH 2 to pH 10 and 0.5 to 2.5 mmol/L, respectively. The optimum operating conditions discovered were 2.5 mg/L initial dye concentration, 0.8 g/L catalyst loading, pH 6 solution and 1.0 mmol/L H2O2 concentration, which successfully removed 71.42 % of Methyl Orange in 1 hour. The sonocatalytic degradation efficiency of the reused catalyst were 64.4 % and 59.6 % in the subsequent usage. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) and titanium dioxide (TiO2) powders were hydrothermally modified in 10 M sodium hydroxide solutions at 120 °C for 24 hours to alter its morphologies. Hydrothermally treated ZnO and TiO2 showed partially rod-shaped particles and used as catalysts in the photocatalytic degradation of Rhodamine B under UV illumination. The effect of operational parameters on degradation efficiency such as catalyst loading (0.5 g/L to 2.5 g/L), initial dye concentration (2.5 ppm to 12.5 ppm), initial H2O2 concentration (0.1 M to 4.0 M) and solution pH (3 to 11) were studied. ZnO showed better photocatalytic activity as compared to TiO2 because ZnO has a lower bandgap energy and more active electron-hole pairs formation in the system. The optimum conditions were 0.5 M H2O2, 1.5 g/L ZnO suspension and 7.5 ppm Rhodamine B at neutral solution pH. The degradation of Rhodamine B followed pseudo first order reaction, with the apparent rate of reaction, kapp = 0.0501 min-1. An effective, efficient and environmental friendly method to remove organic dye from wastewater was developed and could be implemented in treating various types of organic pollutants. [ABSTRACT FROM AUTHOR]

The initial and modified carbon sorbent modified with biologically active polymer - polyvinylpyrrolidone was obtained. Their physical and chemical properties are investigated. The influence of the process of modifying a molded carbon sorbent on its physicochemical properties is shown. The adsorption properties of molded carbon sorbents with respect to marker substances of various nature (organic dyes) under model conditions are studied. The regularities of the effect of the porous structure and the functional composition of the surface of molded carbon sorbents on the adsorption of methylene blue and methanil yellow dyes are established. [ABSTRACT FROM AUTHOR]

Organic dye solutions in suitable liquid solvents are now widely used as a laser gain medium for generating coherent tunable radiation and also in photonic applications. Kirkwood Buff Integrals (KBI’s) play a significant role in characterizing interactions in liquid systems. In this study, we utilise the experimentally obtained sound velocity and density measurements at different concentrations of a dye, 7 Amino-4-(trifluromethyl)coumarin (C10H6F3NO2) in the mixture of ethanol and benzaldehyde over the entire composition range to evaluate these integrals for investigating solute-solvent interactions. [ABSTRACT FROM AUTHOR]

The conversion of ionic state of Ce+4 to Ce+3 up to some extent on doping of trivalent atom open up numerous doors for applications in various fields. Present study aims to synthesize Li doped CeO2 nanoparticles to enhance their photocatalytic activity for organic dyes. Single phase formation of samples is confirmed by X-Ray diffraction method. Reduction in band gap from ~ 3.19 eV to ~ 2.88 eV on Li doping is calculated from Tauc plot obtained using UV vis. Spectroscopy. Degradation of methylene blue (MB) dye is performed under the influence of UV source of light of 365 nm wavelength. Percentage degradation is calculated using absorbance spectra obtained from degraded MB dye solution after each half an hour interval which is found to be ~ 94 %. Hence, this material provides us a hope to use it on a large scale for degradation of industrial waste. [ABSTRACT FROM AUTHOR]

Pure and Ni doped SnO2 nanoparticles (NPs) have been prepared for the application as a photocatalysts to degrade RhB organic dye. Herein, we report that in comparison to pure SnO2, Ni doped NPs exhibit excellent photocatalytic degradation of RhB under UV light. The degradation of dyes is found to be enhancing in the presence of Ni2+ ions as it suppress the electron holerecombination. The high degradation rate of RhB on the as-synthesized 6% Ni-SnOO2 NPs can be attributed to the small size. The degradation mechanism is also discussed. [ABSTRACT FROM AUTHOR]

This work reports the structural and optical properties of pure ZnO, Ag loaded ZnO and Ag loaded ZnOgraphene ternary nanocomposite, and their photo degradation performance was analyzed by using methyl orange and methylene blue as model dyes. Structural confirmation was done by XRD and raman spectroscopy. Band gap of the photocatalysts was analyzed by the UV-visible absorption spectra and were calculated to be 3.19, 3.17 and 3.12 eV for pure ZnO, Ag: ZnO and Ag: ZnO-G respectively. Charge separation of the generated electron-hole pairs was studied by photoluminescence spectroscopy. Ag: ZnO-G ternary nanocomposite showed the best photocatalytic activity in comparison with two other samples. [ABSTRACT FROM AUTHOR]

In the present work, molybdenum trioxide (MoO3) films were deposited at a substrate temperature (TS) of 250 °C on glass substrate by spraying the precursor solution of ammonium heptamolybate tetrahydrate and distilled water using ultrasonic spray pyrolysis technique. XRD and Raman analysis confirms the presence of hexagonal and orthorhombic phases of MoO3. The AFM images show the formation of spherical grains with average size of 0.9 µm. The photoluminescence spectrum of the film shows two emission peaks around 404 and 516 nm. The former one is correlated to band-to-band transition while later one is assigned to defects. The photocatalytic activity of the MoO3 film was studied using Rhodamine-B organic dye under Halogen lamp illumination. The effect of different dye concentrations on photocatalytic performance was also determined. [ABSTRACT FROM AUTHOR]