Increase In Dye Concentration Research Articles

Eco-Friendly Green Approach to the Biosorption of Hazardous Dyes from Aqueous Solution on Ragweed (Ambrosia artemisiifolia) Biomass

The presented research includes the preparation, characterization, and implementation of magnetic biosorbent (Fe3O4/RWB), obtained from ragweed (Ambrosia artemisiifolia) biomass. Fe3O4/RWB was examined for the removal of a hazardous dye, malachite green (MG), from an aqueous solution in a batch system. The effects of the experimental parameters—initial dye concentration (10–300 mg/L), contact time (0–120 min), biosorbent dose (1–5 g/L), initial pH (2–10), ionic strength (0–1 mol/L), and temperature (298–318 K) on dye biosorption—were studied. The results showed that increases in biosorbent dose, contact time, and initial pH led to an increase in biosorption efficiency, while the increase in initial dye concentration, the ionic strength, and temperature had the opposite effect. The biosorption kinetics for MG on Fe3O4/RWB were analyzed with pseudo-first-order, pseudo-second-order, and Elovich kinetic models, while the Langmuir, Freundlich and Temkin isotherm models were used for equilibrium data analysis. It was observed that the MG biosorption followed the pseudo-second-order kinetic model, whereas the Langmuir model was the best fit for the equilibrium biosorption data of MG, with a Qmax of 34.1 mg/g. the desorption of MG from Fe3O4/RWB indicated reusability in five adsorption/desorption cycles, good performance, and potential in practical applications.

Photocatalytic degradation of methylene blue using a Cu2+-modified bimetallic titanium-based metal organic framework (MIL-125) photocatalyst with enhanced visible light activity.

Cu-modified TiO2 nanoparticles derived from MIL-125 were prepared by solvothermal method for the photocatalytic degradation of methylene blue under visible light illumination. For boosting the photocatalytic performance as well as the physicochemical properties of bare sample, 2 wt % Cu2+ ions were integrated into the nodes of the MIL-125 framework. The results showed that incorporation of 2 wt % Cu2+ ions into the MOF framework had significant effects on the crystallographic structure and morphological and optical properties of photocatalytic samples, as well as catalytic activity for the methylene blue degradation reaction. The high activity profile of Cu-modified TiO2 nanoparticles derived from MIL-125 might be attributed to the increased thermal stability, lower band gap energy, and smaller crystallite size of the sample. Activity tests were carried out at five varying MB initial concentrations and four different pH values. According to the findings, an increase in initial dye concentration resulted in a decrease in degradation efficiency. It was observed that increasing the pH value in the range of 3-11 initially led to higher degradation rates until pH 7, after which the degradation rate began to decline.

Preparation of the scattering layer based on SnO2 nanocrystals for dye sensitized solar cell application

Abstract In this work, SnO2 paste was prepared based on (0.1 and 0.12 g) of SnO2 nanoparticles. The SnO2 film was deposited using Screen printing and doctor blade techniques, which it employed as scattering layer in Dye-Sensitized Solar Cell (DSSC). The crystal structure, morphology, and thermal stability of the paste were investigated using XRD, FE-SEM, and TGA techniques. The DSSC parameters were achieved to examining the effect of scattering layer on performance of DSSC. The results showed a crystalline structure predominantly composed of rutile SnO2 crystals arranged in a tetragonal pattern, with individual crystallites measuring approximately 100 nanometers in size. SEM images depicted the surface of SnO2 resembling a sponge with fine pores facilitating dye adsorption and electron mobility. Moreover, a decrease in average particle size was observed with increasing dye concentration, with the average grain size of SnO2 particles being below 100 nanometers at lower dye concentrations. TGA measurements indicated a phase transition occurring around 400 °C.

KINETIC, ISOTHERM AND THERMODYNAMIC STUDIES OF THE ADSORPTION OF CRESOL RED DYE USING AGRICULTURAL WASTES

Agricultural wastes and plant biomass are alternative low-cost adsorbents because they can be used without or with a minimum processing. In the present study, batch experiments were carried out to study the adsorption of cresol red (CR) unto mango leaf (ML) and orange peel (OP). Several parameters that affect adsorption process such as pH, adsorbent dosage, contact time, initial dye concentration and temperature were investigated. FTIR and SEM were used to determine the functional group responsible for adsorption. The results revealed that the highest adsorption efficiency was at pH 5 for the two adsorbents. It was also discovered that CR removal efficiency increased with the increase in contact time and adsorbent dosage while adsorption capacity was higher with increase in initial dye concentration but removal efficiency was lowered. The kinetics conform with the pseudofirst-order kinetic model for mango leaf but conform with the pseudo-second-order kinetic for orange mesocarp due to the value of the correlation coefficient (R2). Based on the value of correlation coefficient, the experimental results for the removal by mango leaf best fitted the Langmuir isotherm model with monolayer adsorption capacity of 70.64 mg. g-1, while Freundlich isotherm model was best fitted to the experimental results for the adsorption of CR by Orange peel. The thermodynamic results revealed that the process is spontaneous and endothermic.

Response of soil fungi to textile dye contamination

This study examines the impact of textile dye contamination on the structure of soil fungal communities near a Shaoxing textile dye factory. We quantified the concentrations of various textile dyes, including anthraquinone azodye and phthalocyanine, which ranged from 20.20 to 140.62 mg kg^-1, 102.01–698.12 mg kg^-1, and 7.78–42.65 mg kg^-1, respectively, within a 1000 m radius of the factory. Our findings indicate that as dye concentration increases, the biodiversity of soil fungi, as measured by the Chao1 index, decreases significantly, highlighting the profound influence of dye contamination on fungal community structure. Additionally, microbial correlation network analysis revealed a reduction in fungal interactions correlating with increased dye concentrations. We also observed that textile dyes suppressed carbon and nitrogen metabolism in fungi while elevating the transcription levels of antioxidant-related genes. Enzymes such as lignin peroxidase (LiP), manganese peroxidase (MnP), laccase (Lac), dye-decolorizing peroxidases (DyPs), and versatile peroxidase (VP) were upregulated in contaminated soils, underscoring the critical role of fungi in dye degradation. These insights contribute to the foundational knowledge required for developing in situ bioremediation technologies for contaminated farmlands.

Comparative Investigation of the Color Removal Efficiency of Different Mosses Species from Dye Solutions

In this study, Acid Red 88 (Sodium 4-(2-hydroxy-1-naphthalenylazo)-naphthalenesulfonate) dye solution, which is used extensively in textile industry, was used. Dye removal efficiency determination studies were firstly performed by using three moss species, Chiloscyphus polyanthus, Cinclidotus pachylomoides and Palustriella Falcata (Hedw). In the case of comparison of color removal efficiency of Chiloscyphus polyanthus, Cinclidotus Pachylomoides and Palustriella Falcata (Hedw), it was seen that the species with the highest color removal efficiency with increasing dye concentration was determined for Palustriella Falcata (Hedw). Furthermore, the effect on color removal efficiency was determined at specific concentration, pH and under UVA (Ultraviolet-A) lamp light by using a photo reactor with these mosses species. It has also been detected that these three mosses can be used in photocatalytic studies. Thus, these three mosses species can be employed as color removing material both separately and with UVA light.

In-situ homeotropic alignment of dye doped liquid crystal molecules on multilayered self assembled nanoparticles in confined cells for next generation display devices

The in-situ homeotropic alignment (HA) of pure liquid crystal (LC) and dye doped LC molecules was prepared on the multilayered self assembled silica nanoparticles (SNPs) deposited on the substrates in a confined empty ITO cell. The LC and azo dye mixtures with (0.0625–0.5 wt%) concentrations show the uniform in-situ HA of nematic LC (NLC) over SNPs coated surface. The surface morphology with mapping of elements and functionality of the SNPs coated ITO glass substrate were confirmed by “field emission scanning electron microscope (FESEM)” and “X-ray photoelectron spectroscopy (XPS)”. Polarized optical microscopic textures and conoscopic view of pure and dye doped LC mixtures in SNPs coated confined cells, confirmed the HA of LC molecules and exhibited the uniform black textures under crossed polarizers. The electro-optic behaviour of dye doped homeotropically aligned LC (HALC) cells was compared to pure SNPs coated HALC cell. The results showed that on increasing the azo dye concentration (0.0625–0.25 wt%), the threshold (Vth) and operating (Vo) voltages were found decreased. However, on further increase of dye concentration to 0.5 wt%, Vth and Vo were observed relatively increased. The contrast ratio (CR) was found improved in dye doped HALCs with maximum CR at lowest dye concentration (0.0625 wt%). The UV results exhibit higher absorbance of the dye doped HALC cells with increasing the dye concentration. Also, the band gap values showed that the addition of even small amount of dye, it reduced the value of band gap in HALC cell.

Advancing fluorescence imaging: enhanced control of cyanine dye-doped silica nanoparticles

BackgroundSilica nanoparticles (SNPs) have immense potential in biomedical research, particularly in drug delivery and imaging applications, owing to their stability and minimal interactions with biological entities such as tissues or cells.ResultsWith synthesized and characterized cyanine-dye-doped fluorescent SNPs (CSNPs) using cyanine 3.5, 5.5, and 7 (Cy3.5, Cy5.5, and Cy7). Through systematic analysis, we discerned variations in the surface charge and fluorescence properties of the nanoparticles contingent on the encapsulated dye-(3-aminopropyl)triethoxysilane conjugate, while their size and shape remained constant. The fluorescence emission spectra exhibited a redshift correlated with increasing dye concentration, which was attributed to cascade energy transfer and self-quenching effects. Additionally, the fluorescence signal intensity showed a linear relationship with the particle concentration, particularly at lower dye equivalents, indicating a robust performance suitable for imaging applications. In vitro assessments revealed negligible cytotoxicity and efficient cellular uptake of the nanoparticles, enabling long-term tracking and imaging. Validation through in vivo imaging in mice underscored the versatility and efficacy of CSNPs, showing single-switching imaging capabilities and linear signal enhancement within subcutaneous tissue environment.ConclusionsThis study provides valuable insights for designing fluorescence imaging and optimizing nanoparticle-based applications in biomedical research, with potential implications for targeted drug delivery and in vivo imaging of tissue structures and organs.Graphical

Adsorptive decolorization of brilliant green dye in aqueous media using various modified MOF-5 adsorbents

Dye pollution in environmental water is a serious problem worldwide, posing significant environmental and health concerns. To effectively address this problem, this study investigates the adsorptive decolorization of brilliant green (BG) dye in aqueous media by using various metal-organic frameworks (MOF-5)-based adsorbents modified with industrial wastes (coal fly ash (CFA) and rice husk ash (RHA)). The adsorption experiments were conducted to evaluate their performance under varying conditions, and the synthesized and spent adsorbents (selected) were characterized. The results showed that the adsorbent samples possessed the characteristics of a good adsorbent. MOF-5 coated with thermally treated RHA at 900 °C (MOF-5@ RHA900 – with BET surface area = 91.6810 m2 g−1) has the highest observed BG dye adsorption efficiency (92%) and adsorption capacity (30.22 mg g−1) at adsorbent mass of 1.4 g, contact time of 2 h, and initial dye concentration of 20 mg L−1. BG dye removal increased with an increase in contact time and adsorbent amount and decreased with an increase in initial dye concentration. The adsorption kinetics and isotherm equilibrium studies revealed that the adsorption data were best fitted to the pseudo-second-order kinetic model (R2 = 0.9507) and Langmuir isotherm model (R2 = 0. 0.9929), respectively. These findings highlight the potential of mesoporous MOF-5@ RHA900 as an effective adsorbent for BG dye decolorization in aqueous media, with implications for water treatment and the utilization of industrial waste materials.

Exploring fungal-mediated solutions and its molecular mechanistic insights for textile dye decolorization

Decolorization of textile dyes and study of their intermediate compounds is necessary to comprehend the mechanism of dye degradation. In the present study, different fungal mediated solutions were explored to provide an alternative to treat the reactive dyes. Growing biomass of Pleurotus sajor caju showed 83% decolorization (249.99 mg L−1 removal) of Reactive Blue 13 (RB 13) and 63% decolorization (188.83 mg L−1) of Reactive Black 5 (RB 5) at 300 mg L−1 initial concentration on 8 d. Higher laccase activity was positively correlated with increase in decolorization. However, increasing dye concentration has inhibitory effect on fungal biomass due to increase in toxicity. In laccase mediated decolorization, laccase produced from P. sajor caju using carbon rich waste material as substrate showed 89% decolorization (276.36 mg L−1 removal) of RB 13 and 33% decolorization (105.37 mg L−1 removal) of RB 5 at 300 mg L−1 initial dye concentration in 100 min at 30 °C and pH 3.0’. Comparing the two methods, laccase-mediated decolorization shows better decolorization in less time and does not produce sludge. Further, the present work also attempted to study the dye degradation pathway for Reactive blue 13 via laccase mediated process. Fourier-transform infrared spectroscopy (FTIR), high-performance liquid chromatography (HPLC), and gas chromatography–mass spectrometry (GC-MS) were utilized to identify the degraded products. The GC-MS analysis showed the formation of naphthalene, naphthalene 2-ol, benzene,1–2, dicarboxylic acid, 4, amino, 6,chloro, 1-3-5, triazin-2-ol as the final degraded products after enzymatic degradation of RB 13. These findings provide in-depth study of laccase-mediated textile dye degradation mechanism.

A hybrid electrocoagulation-biocomposite adsorption system for the decolourization of dye wastewater

Among the various methods for the removal of azo dye, electrocoagulation is recognized to be highly efficient. However, the process is associated with high operation and maintenance cost, which demands the need for reducing the electrolysis time without compromising the performance efficiency. This can be achieved by adopting hybrid electrocoagulation process with a low-cost but effective process, such as adsorption. The study investigated the performance of a hybrid electrocoagulation-biocomposite system (H-EC-BC) for removing methyl orange dye. Firstly, the operating parameters of electrocoagulation process were optimized and a removal efficiency of 99% has been attained using Fe-SS electrodes at a pH of 6 for a reaction time of 30 min. The performance of EC process was found to be decreasing with increase in dye concentration. Secondly, biocomposite was synthesized from Psidium guajava leaves and characterized using SEM, FTIR, EDAX, and XRD analyses. The results suggested that it is having a porous nature and cellulose crystal structure and confirmed the presence of chemical elements such as carbon (65.2%), oxygen (29.1%) as primary with Fe, Cl, Na and Ca as secondary elements. The performance of the biocomposite was evaluated for the dye adsorption using spectrophotometric methods. Various operating parameters were optimized using experimental methods and a maximum removal efficiency of 65% was achieved at a pH of 6, dosage of 5 g/L and an adsorption contact time of 120 min. The maximum efficiency (92.78%) was obtained with Fe-SS electrodes and KCl as a sustaining electrolyte under acidic circumstances (pH 6). The biocomposite was observed to be more efficient for higher dye concentration. Langmuir and Freundlich adsorption isotherms were fitted with the experimental results with R2 values as 0.926 and 0.980 respectively. The adsorption kinetics were described using Pseudo-first and Pseudo-second order models, wherein Pseudo-second order model fits the experimental results with R2 value of 0.999. The energy consumption of electrocoagulation (EC) process in the hybrid H-EC-BC system was compared to that of a standard EC process. The results demonstrated that the hybrid system is approximately 7 times more energy efficient than the conventional process, thereby implicating its adaptability for field application.

Synthesis, characterization of KAlPO4F and its application for methyl violet adsorption

KAlPO4F was prepared hydrothermally at 453 K, a time-saving method using cheap reagents. The white solid was characterized by different methods such as powder X-ray diffraction, thermal analysis, SEM and UV–Vis diffuse reflectance. The compound was successfully tested for the removal of methyl violet (MV), a hazardous dye. Experiments were carried out as a function of contact time, initial concentration, temperature and pH. The amount of dye uptake was found to vary with increasing initial solution pH and maximum adsorption was observed at pH 10; the equilibrium was attained in 270 min. The amount of dye uptake (mg/g) was found to increase with increase in dye concentration and contact time. The pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models were applied to fit the experimental data to elucidate the kinetic adsorption. The pseudo-second-order model was the best to describe the adsorption process. Different models analyzed the equilibrium isotherms; the applicability for the experimental data follows the order: Freundlich > Langmuir > Temkin. The thermodynamic parameters: ΔH° (39.034 kJ mol−1), ΔS° (134 J K−1 mol−1) and ΔG° (− 367.01 J mol−1) indicated that the adsorption process is endothermic and spontaneous with increasing disorder at the solid–solution interface.

Preparation and characterization of high flux cellulose acetate/hydroxyapatite composite ultrafiltration membranes for water treatment

In this study, we prepared cellulose acetate/hydroxyapatite (CA/HA) composite ultrafiltration membranes for water treatment. The organic-inorganic composite ultrafiltration membranes were prepared by doping different contents of HA nanoparticles into the CA by phase inversion method. The structure and morphology of the HA nanoparticles and membranes were characterized by X-ray diffraction, Fourier infrared spectroscopy and Scanning electron microscopy. Thermogravimetric analysis was used to describe thermal characteristics. The contact angle value and wettability test were used to determine the hydrophilicity of the polymer membrane. In addition, fluxes and rejection rates were tested at different pollutant concentrations and different pH values. The pore size and porosity gradually increased and the hydrophilicity and thermal stability of membrane were improved with the deposited HA content. With the addition of 5 wt% HA, the tensile strength of the membrane reached a maximum value of 2.80 MPa. The fluxes of pure water, CR, MB and BSA were 152.23, 111.25, 125.69 and 87.47 L/(m2·h), while the rejection rates of CR, MB and BSA were 99.99 %, 92.91 % and 99.99 %, respectively. In addition, the rejection decreased with increasing dye concentration and showed higher rejection under alkaline conditions. On the whole, the produced CA/HA composite membranes exhibited significantly higher permeability and rejection rates, offering them a lot of potential for water treatment applications.

Use of oak acorns adsorbent and response surface methodology for removal of crystal violet from aqueous solution

ABSTRACTThis study investigates the potential use of oak acorn pericarp powder as an effective adsorbent for removing crystal violet from aqueous solutions under citric acid activation. Various analytical techniques, including FTIR, EDS, and SEM, were used to examine the characteristics of the adsorbent obtained. Throughout the experiments, parameters such as adsorbent quantity, solution pH, and initial dye concentration were meticulously taken into account. To optimise this removal process, a customised experimental approach based on response surface methodology (RSM) was adopted, involving the performance of 20 series of experiments to assess the influence of key variables, including adsorbent dose (A), pH (B), and initial dye concentration (C), as well as their interactions. Statistical analysis reveals the high significance of the elimination model, supported by an extremely low probability value (p < 0.0001). Notably, increasing adsorbent mass and solution pH leads to higher rates of crystal violet removal. Conversely, as the initial dye concentration increases, the removal rate decreases. Furthermore, the interaction between these variables does not appear to have a significant influence. Under optimal conditions, a remarkable elimination rate of 99.96% was achieved. This involved a solution with an initial pH of 10.82, an adsorbent dose of 28.5 mg, and an initial dye concentration of 17.8 mg/L. The kinetics of crystal violet adsorption onto the adsorbent were effectively described by a pseudo-second-order equation. Additionally, the optimal multilayer uptake capacity of OA@CA for CV dye was determined to be 135.9 mg.g−1, and the Freundlich model demonstrated a significantly better fit to the experimental results when compared to the Langmuir model.

Granular titanium dioxide and silicon‐doped titanium dioxide as reusable photocatalysts for dye removal

AbstractIn this study, photocatalytic oxidation of methylene blue (MB) and malachite green (MG) dyes was investigated using granular pure titanium dioxide and silicon‐doped granular titanium dioxide as photocatalysts. Both catalysts were used repeatedly throughout the photocatalytic oxidation experiments. The effect of initial dye and catalyst concentration on photocatalytic oxidation was investigated. The photocatalytic oxidation followed first‐order kinetics for both catalysts. The efficiency of photocatalytic oxidation increased with the increasing catalyst concentration and decreased with the increasing dye concentration. In a 60‐min reaction using granular titanium dioxide, removal efficiencies of MB and MG at 20 g/100 mL catalyst loading and 10 mg/L initial concentration were 83% and 93.3%, respectively. In a 60‐min reaction using granular silicon‐doped titanium dioxide, the removal efficiencies of MB and MG at 5 g/100 mL catalyst loading and 10 mg/L initial concentration were 90.2% and 91.6%, respectively.

Examining Energy Storage Potential in Weakly Polar Nematic Liquid Crystals Infused with Anthraquinone Dye: A Comprehensive Approach

The applications of liquid crystals in the field of renewable, clean and sustainable technologies of energy storage are of utmost importance at present. This paper delves into dielectric spectroscopic studies of a weakly polar nematic liquid crystal (NLC) enriched with an anthraquinone dye. The primary objective is to assess the impact of increasing dye concentrations on various properties. Anthraquinone dye has been found to increase the dielectric permittivity of weakly polar NLC, leading to a 4.7-fold increase in dielectric anisotropy. Simultaneously, a reduction of around 11% in threshold and operating voltages of the NLC has also been recorded after using dye as the guest material. The added dipolar contributions provided by dye molecules have been attributed to this surplus permittivity. The NLC has been found to have an approximately 54% faster response to the applied field. The intrinsic polarization field of dye molecules accelerates nearby LC molecule reorientation, leading to a 56.5% faster fall time and a 29.8% faster rise time in a 3.0 wt% dye-doped LC cell. These experimental results have been validated via computational studies as well. The simulation results about dipole moment and polarizability provide robust support for our experimental results. Such composites evince their potential for energy storage and 5G communication technologies with adjustable impedance and permittivity.

Efficient separation of dyes using two-dimensional heterogeneous composite membranes

Two-dimensional materials are widely used in membrane separation, but the loose distribution and severe expansion between graphene oxide (GO) nanosheets limit its application. Here, we introduce a two-dimensional MOF material into the GO membrane to enhance its water permeance and separation performance. The MOF/GO composite membrane was prepared by vacuum filtration. The MOF and GO nanosheets were tightly stacked through the π-π effect, and the shortened transmission path and enhanced pore structure greatly improved the water permeance of the composite membrane. The MOF/GO membrane exhibited a high water permeance of 56.94 L m−2 h−1 bar−1. The rejection rates of methylene blue and was as methyl orange dyes were as high as 99.79% and 99.11%, respectively. At increased dye concentration, the rejection rate of methylene blue was still maintained greater than 99%. Dye rejection after 18 h of continuous operation remains above 90%. This work provides new ideas for improving membrane separation materials. The combination of two-dimensional heterogeneous materials can result in synergistic advantages for the development of composite membranes with high water permeance and high rejection rate.

Fundamental Understanding of Dye Coverage and Performance in Dye-Sensitized Solar Cells Using Copper Electrolyte

Dyes have played a pivotal role in the advancement of modern dye-sensitized solar cells (DSCs), as they not only facilitate light harvesting, but also serve as blocking layers to impede recombination. In this study, we conducted a systematic investigation to elucidate the influence of dye coverage on the photovoltaic parameters of copper-electrolyte-based DSCs by precisely controlling the dye coverage on the TiO2 substrate using D35 organic dye solutions with varying concentrations. The dye loading increased proportionally with the increase in dye concentrations until it reached saturation at a concentration of 0.2 mM. However, an optimal dye concentration of 0.1 mM was determined in terms of achieving the highest photovoltaic performance, under both outdoor and indoor light conditions. Notably, a maximum power conversion efficiency (PCE) of 6.50 ± 0.25% under outdoor illumination (100 mW/cm2) and 10.48 ± 0.30% under indoor light (1000 lux, WW CFL) was attained using a 0.1 mM D35 dye concentration. Additionally, the dark current and ideality factor (m) were found to be minimized at the 0.1 mM dye concentration. Furthermore, the ideality factor (m) exhibited disparities between indoor and outdoor light conditions. The lifetime obtained from electrochemical impedance spectroscopy (EIS) measurements correlated well with the ideality factor (m) and dark current. Notably, electron injection, dye regeneration, charge collection, and ion diffusion were observed to be independent of the dye coverage.

Raw sawdust utilization for the removal of acid red57 and basic fuchsin dyes from aqueous solution: equilibrium, kinetics, and thermodynamic investigation

The aim of work is the use of a cheap adsorbent; sawdust (SD), for the adsorption of anionic dye, acid red57 (AR57), and cationic dye, basic fuchsin (BF). The adsorption of AR57 and BF on SD increased by increasing contact time and adsorbent dosage, while decreased with the increase of temperature and initial dye concentration. The increase in pH decreased the adsorption of AR57 and increased the adsorption of BF. The effective pH, adsorbent dose, and contact time on the AR57 removal efficiency were found to be 3, 0.1 g and 50 min, respectively. While for BF it was found to be 6, 0.2 g and 50 min, respectively. Fitting equilibrium data to Langmuir, Freundlich and Temkin isotherms showed that Freundlich model is the most suitable to describe the acid red57 and basic fuchsin. The kinetic studies indicate that the adsorption of AR57 and BF follows a pseudo-second-order model. The adsorption of both AR57 and BF is spontaneous (ΔG = −3.97, −3.27 kJ/mol) and exothermic (ΔH = −22.9, −8.3 kJ/mol) with negative values of ΔG and ΔH. The negative values of ΔS of both AR57 and BF (ΔS = −64.6, −16.7 J/mol. K) showed that the randomness decreases through the adsorption process.

Experimental and Theoretical Evaluation of a Commercial Luminescent Dye for PVT Systems

Combining photovoltaic (PV) and photo-thermal (PT) energy collection strategies in a single system can enhance solar energy conversion efficiencies, leading to increased economic returns and wider adoption of renewable energy sources. This study focuses on incorporating a commercial luminescent organic dye (BASF Lumogen F Red 305) into ethylene glycol to explore its potential for PVT applications. The optical and electrical characteristics of the working fluid were evaluated at different temperatures under direct solar irradiance. Pristine ethylene glycol reduced the maximum PV cell temperature by 10 °C. The inclusion of luminescent dye at various concentrations further reduced the maximum temperature, with the lowest concentration achieving a 7 °C decrease compared to pristine ethylene glycol. The highest dye concentration (0.50 wt%) resulted in a significant temperature reduction of 12 °C. While electrical conversion efficiencies decreased with increasing dye concentration, all concentrations exhibited higher fill factors compared to the bare PV cell during the 100-min illumination period. A ray-tracing model was employed to analyze the behavior of the luminescent dye and quantify transmitted energy for electricity and thermal energy production. Different concentrations showed varying energy outputs, with lower concentrations favoring electrical energy and higher concentrations favoring thermal energy. Economic assessment revealed the viability of certain concentrations for specific countries, highlighting the trade-off between thermal and electrical energy generation. These findings provide valuable insights for PVT system applications in different geographical and economic contexts.