Organic Dyes Research Articles

Applications of Titanium Dioxide (TiO2) Nanoparticles in Photocatalysis

Titanium dioxide nanoparticles (TiO2 NPs) are conspicuously preferred as photocatalyst among the transition metal oxide nanoparticles. It exhibited in three polymorphisms of steady state rutile phase while brookite and anatase sustaining in metastable phase. The mixed phases of anatase phase and rarely found brookite phase mostly preferred for the photodegradation applications. The economically affordable along with nontoxic nature on top of excellent opto-electronics and catalytic properties of TiO2 NPs are eminently favorable for the photocatalytic degradation of chemically complex structured numerous organic and inorganic dyes, phenol and phenol-based derivatives, passive microplastics as well as suspended matters, non-biodegradable cytostatic drugs, acetaminophen, pharmaceutical organic waste compounds in addition to water pollutants. The photocatalytic capability of these NPs enhanced by upgrading the structural and morphological nature by opting different synthesis techniques as well preparing the nanocomposites of TiO2 incorporation with other metals. The hydrothermally prepared polymeric membranes of polyvinylidene with TiO2 NPs effectively (more than 90%) removed 17 α–ethinylestradiol from the contaminated water compared to Diclofenac under Uv irradiation. As it fronting the issue of electrostatic repulsion to all other membranes surface. The grafted membrane recorded highest degradation efficiency of 95.4% and best reusability of 90% saturated at fifth recycle for Methylene Blue azo dye compared with blending and dip coating membranes. The TiO2 modified ultrafiltration membranes of Polyvinylidene Fluoride with Dopamine illustrated the 92.6% photocatalytic degradation of Sulfadiazine which is most hazardous and highly resistant to biodegradation. 100% degradation of phenol derivative by TiO2 NPs hybrid polymeric films in visible light irradiation. The degradation efficiency of heterogenous photocatalyst Carbon–TiO2 contained anatase and brookite phased for Methylene Blue dye was 100% while for Rhodamine–B higher than 99% in solar and more than 78% in LED light irradiation. The recent trends for improvisation of photocatalytic ability of TiO2 NPs to enhance the quality of water and hence the mankind are elaborated.

Near-Infrared Absorbing Aza-BODIPY Dyes for Optoelectronic Applications.

Organic dyes that absorb light in the visible to near-infrared region have garnered significant interest, owing to their extensive utility in organic photovoltaics and various biomedical applications. Aza-boron-dipyrromethene (Aza-BODIPY) dyes are a class of chromophores with impressive photophysical properties such as tunable absorption from the visible region towards near infrared (NIR) region, high molar absorptivity, and fluorescence quantum yield. In this review, we discuss the developments in the aza-BODIPYs, related to their synthetic routes, photophysical properties and their applications. Their design strategies, modifications in chemical structures, mode/position of attachment, and their impact on photo-physical properties are reviewed. The potential applications of aza-BODIPY derivatives such as organic solar cells, photodynamic therapy, boron-neutron capture therapy, fluorescence sensors, photo-redox catalysis, photoacoustic probes and optoelectronic devices are explained.

Introduction of Organic Dyes into Cadmium(II) MOF for Tunable Light Emission and Highly Sensitive Probing Antibiotics

AbstractA honeycomb porous cadmium(II) metal–organic framework {[Cd(L)(H2O)] ⋅ NMP ⋅ 5H2O}n (1, H2L=1‐(4‐carboxyphenyl)‐1H‐pyrazole‐3‐carboxylic acid and NMP=1‐methyl‐2‐pyrrolidinone) was obtained using the solvothermal method. The luminescent molecules rhodamine B (RhB) and fluorescein (FL) were encapsulated in 1 using the immersion method to prepare RhB@1 and FL@1 dual emission composites. Additionally, a series of RhBx/FL1‐x@1 composites with varying luminescence properties were generated by altering the molar ratio of RhB to FL. Furthermore, the photoluminescence of RhB@1 and FL@1 was demonstrated to be caused by photoelectron transfer and fluorescence resonance energy transfer from 1 to the encapsulated guest module. Notably, RhB@1 showed the considerable improvement in fluorescence selectivity and detection limit (10−6 M) for metronidazole and dimetronidazole with remarkable recyclability.

Unveiling the potential of TPA-based molecules to tune the optoelectronic properties and enhance the efficiency of dye-sensitized solar cells.

The world's energy and environmental requirements are changing due to rapid population growth and industrial growth, and solar cells can be used to meet these demands. Dye-sensitized solar cells (DSSCs) are solar cells in which energy conversion occurs via a process similar to photosynthesis in plants. DSSC development is still in its infancy. DSSCs can operate under cloudy conditions and indirect sunlight and have attracted considerable attention due to their low cost and high efficiency. We designed two metal-free TPA-based dyes (Dye2 and Dye3) based on the reference dye Mg207 (Dye1) by increasing the donor strength of the molecule, as such dyes have shown enhanced efficiency in DSSCs. Moreover, the triphenylamine (TPA) moiety has been demonstrated to be a good donor that prevents charge recombination. Intramolecular charge transfer (ICT) from the donor to acceptor moiety was found in the sensitizers, and electrons were promoted to the conduction band (CB) of the TiO2 semiconductor. The negative binding energy of the dye@TiO2 clusters indicated that dye adsorption on the semiconductor surface was stable. The double donor increased the electron injection and electronic coupling constants in Dye2 and Dye3, indicating that these newly designed dyes have superior charge injection capacity. Accordingly, the efficiencies of DSSCs with Dye2 and Dye3 were 9.77% and 9.62%, respectively, and substitution with the TPA unit at the -R1 and -R2 positions in Dye1 resulted in better power conversion compared to the parent compound (9.09%). Increased donor strength improved photovoltaic performance by increasing current density and light-harvesting efficiency. This is a good molecular design approach for preparing targeted donor- -acceptor (D- -A) organic dyes with high DSSC efficiency. To predict the charge transport and optoelectronic characteristics of the TPA dyes, quantum chemical calculations were carried out using Gaussian16. The ground-state (S0) optimized geometries of the sensitizers were computed by utilizing DFT at the B3LYP/6-31G** level. The absorption spectra ( max) were computed by employing TD-DFT with various functionals (B3LYP, PBE1PBE, CAM-B3LYP, and BHandHLYP) in the gas and solvent (DCM) phases. Among the studied functionals, BHandHLYP was found to be best at successfully reproducing the experimental data. Thus, the absorption spectra of the newly designed dyes and dye@TiO2 were calculated at the BHandHLYP/6-31G** level. The dye@TiO2 cluster optimizations were carried out at the B3LYP/6-31G**(LANL2DZ) level.

Fe-Doped g-C3N4/Bi2MoO6 Heterostructured Composition with Improved Visible Photocatalytic Activity for Rhodamine B Degradation.

The binary heterostructured semiconducting visible light photocatalyst of the iron-doped graphitic carbon nitride/bismuth molybdate (Fe-g-C3N4/Bi2MoO6) composite was prepared by coupling with Fe-doped g-C3N4 and Bi2MoO6 particles. In the present study, a comparison of structural characteristics, optical properties, and photocatalytic degradation efficiency and activity between Fe-doped g-C3N4 particles, Bi2MoO6 particles, and Fe-g-C3N4/Bi2MoO6 composite was investigated. The results of X-ray diffraction (XRD) examination indicate that the hydrothermal Bi2MoO6 particles have a single orthorhombic phase and Fourier transform infrared (FTIR) spectroscopy analysis confirms the formation of Fe-doped g-C3N4. The optical bandgaps of the Fe-doped g-C3N4 and Bi2MoO6 particles are 2.74 and 2.73 eV, respectively, as estimated from the Taut plots obtained from UV-Vis diffuse reflectance spectroscopy (DRS) spectra. This characteristic indicates that the two semiconductor materials are suitable for absorbing visible light. The transmission electron microscopy (TEM) micrograph reveals the formation of the heterojunction Fe-g-C3N4/Bi2MoO6 composite. The results of photocatalytic degradation revealed that the developed Fe-g-C3N4/Bi2MoO6 composite photocatalyst exhibited significantly better photodegradation performance than the other two single semiconductor photocatalysts. This property can be attributed to the heterostructured nanostructure, which could effectively prevent the recombination of photogenerated carriers (electron-hole pairs) and enhance photocatalytic activity. Furthermore, cycling test showed that the Fe-g-C3N4/Bi2MoO6 heterostructured photocatalyst exhibited good reproducibility and stability for organic dye photodegradation.

Preparation of thiourea derivative incorporated Ag3PO4 core shell for enhancement of photocatalytic degradation performance of organic dye under visible radiation light

Photocatalysis is a promising technique to reduce hazardous organic pollutants using semiconductors under visible light. However, previous studies have been concerned with the behavior of silver phosphate (Ag3PO4) as n-type semiconductors, and the problem of their instability is still under investigation. Herein, 4,4′-(((oxalylbis(azanediyl)) bis(carbonothioyl)) bis(azanediyl)) dibenzoic acid is synthesized by green method and used to enhance the photocatalytic behavior for Ag3PO4. The incorporated Ag3PO4 core–shell is prepared and characterized via XRD, FT-IR, Raman, TEM and BET. Besides, the thermal stability of the prepared core shell was investigated via TGA and DSC measurements. The optical properties and the energy band gap are determined using photoluminescence and DRS measurements. The photodegradation of methylene blue in the presence of the synthesized Ag3PO4 core–shell under visible light is examined using UV/Vis measurements. The effect of initial dye concentration and contact time are studied. In addition, the kinetic behavior of the selected dye during the photodegradation process shows a pseudo-first order reaction with rate constant of 0.015 min−1 for ZAg. The reusability of the Ag3PO4 core shell is evaluated, and the efficiency changed from 96.76 to 94.02% after three cycles, indicating efficient photocatalytic behavior with excellent stability.

Biomimetic solar evaporator for continuous clean water production with synergistic organic dye wastewater remediation

Solar-driven water evaporation is recognized as an environment-friendly technology for sustainable clean water generation, serving the needs of both desalination and wastewater purification. However, its practical application is constrained by challenges such as single functionality and significant salt accumulation. Inspired by the transpiration of vascular plant, this work introduces a scalable and cost-effective biomimetic evaporator (PyCOF/Tri-Layers), consisting of a biomimetic hierarchical fibrous membrane (Tri-Layers) and a composite photothermal layer (PyCOF). Furthermore, the PyCOF composite, featuring an aloe-like flower structure, enhances the light trapping (95.1 %) through multiple scattering, realizing simultaneous desalination and azo dye degradation. Based on the PyCOF/Tri-Layers evaporator, we demonstrate a suspended multi-section hanging evaporation structure sustaining a consistent evaporation rate of approximately 1.41 kg m−2 h−1 over 15 days without salt accumulation, achieving above 99.3 % removal of dye pollutants within 120 min under one sun irradiation. Moreover, in outdoor experiments, the improved evaporator realizes a daily clean water yield rate of 8.73 kg m−2 d−1, and the collected water is suitable for supporting crop cultivation within an integrated solar desalination-cultivation system. This work not only provides a one-stone-two-birds approach for generating clean water from polluted seawater, but also presents promising possibilities for offshore self-sustainable agriculture production.

Repurposing Visible-Light-Excited Ene-Reductases for Diastereo- and Enantioselective Lactones Synthesis.

Repurposing enzymes to catalyze non-natural asymmetric transformations that are difficult to achieve using traditional chemical methods is of significant importance. Although radical C-O bond formation has emerged as a powerful approach for constructing oxygen-containing compounds, controlling the stereochemistry poses a great challenge. Here we present the development of a dual bio-/photo-catalytic system comprising an ene-reductase and an organic dye for achieving stereoselective lactonizations. By integrating directed evolution and photoinduced single electron oxidation, we repurposed engineered ene-reductases to steer non-natural radical C-O formations (one C-O bond for hydrolactonizations and lactonization-alkylations while two C-O bonds for lactonization-oxygenations). This dual catalysis gave a new approach to a diverse array of enantioenhanced 5- and 6-membered lactones with vicinal stereocenters, part of which bears a quaternary stereocenter (up to 99 % enantiomeric excess, up to 12.9 : 1 diastereomeric ratio). Detailed mechanistic studies, including computational simulations, uncovered the synergistic effect of the enzyme and the externally added organophotoredox catalyst Rh6G.

Repurposing Visible‐Light‐Excited Ene‐Reductases for Diastereo‐ and Enantioselective Lactones Synthesis

AbstractRepurposing enzymes to catalyze non‐natural asymmetric transformations that are difficult to achieve using traditional chemical methods is of significant importance. Although radical C−O bond formation has emerged as a powerful approach for constructing oxygen‐containing compounds, controlling the stereochemistry poses a great challenge. Here we present the development of a dual bio‐/photo‐catalytic system comprising an ene‐reductase and an organic dye for achieving stereoselective lactonizations. By integrating directed evolution and photoinduced single electron oxidation, we repurposed engineered ene‐reductases to steer non‐natural radical C−O formations (one C−O bond for hydrolactonizations and lactonization‐alkylations while two C−O bonds for lactonization‐oxygenations). This dual catalysis gave a new approach to a diverse array of enantioenhanced 5‐ and 6‐membered lactones with vicinal stereocenters, part of which bears a quaternary stereocenter (up to 99 % enantiomeric excess, up to 12.9 : 1 diastereomeric ratio). Detailed mechanistic studies, including computational simulations, uncovered the synergistic effect of the enzyme and the externally added organophotoredox catalyst Rh6G.

Synthesis, Characterization, Antibacterial and Photocatalytic Studies of Metal Oxides Coupled Nanocomposites

AbstractIn this study, we present a one‐pot synthetic approach for the preparation of metal oxide nanocomposites. Our investigation combines various analytical techniques, including FTIR, XRD, UV‐vis DRS, PL, XPS, SEM, EDX, and XANES, to comprehensively identify heterogeneous structures: SnO2‐CuO, CuO‐SnO2, NiO‐TiO2, and TiO2‐NiO. These metal oxide‐linked semiconductor solids serve as catalysts for dye photodegradation and exhibit remarkable biological activity. Our research is centered on exploring the photocatalytic potential of SnO2‐CuO nanocomposites while emphasizing the optimization of their photocatalytic and biological activities. This optimization is achieved through the careful incorporation of an ideal quantity of SnO2, as confirmed by EDX data, which reveals the composition as follows: O: 78.58 weight percent (0.525 keV), Cu: 12.61 weight percent (0.954 keV), and Sn: 8.81 weight percent (0.400 keV). Notably, under direct sunlight irradiation, the degradation efficiency of Rhodamine B dye surpasses that of pristine CuO, SnO2, TiO2, and NiO nanoparticles. Additionally, we explore the antimicrobial properties of these prepared samples at varying concentrations (50, 100, and 150 μl) against the pathogenic bacterium Staphylococcus aureus. Our findings highlight their effectiveness as antimicrobial agents. This research offers a promising method for developing highly active metal‐oxide‐linked nanomaterials, suitable for efficiently removing organic dye contaminants from water systems and showing great potential in antimicrobial applications.

One step synthesis of a novel Co-doped UiO-66 adsorbent for superior adsorption of organic dyes from wastewater

Metal-organic frameworks (MOFs) is a promising material that can be used in many fields, including environmental remediation. In this work, a novel adsorbent was successfully prepared by doping the Co element into the framework of UiO-66 with an in-situ oil bath synthesis. This modification ensured that the materials retained relatively good crystallinity. The Co-doping process had a major impact on the particle size and morphology of the original MOFs. The CoUiO-2 exhibited larger surface area and pore size than pristine UiO-66. Accordingly, the maximum adsorption amount of malachite green (MG) on CoUiO-2 (628.93 mg/g) was significantly larger compared with UiO-66 (343.64 mg/g), which was due to more active adsorption sites. In addition, the CoUiO-2 also showed a superior adsorption capacity on rhodamine B (RhB) (1106.22 mg/g). The adsorption process was well described by both the pseudo-second order and Langmuir models, indicating it was dominated by chemisorption and the adsorbent had a homogeneous surface area for adsorption. Therefore, the CoUiO-2 material could be a promising adsorbent for wastewater treatment. This work can provide an important insight into the modification of MOF materials and identify further opportunities to promote the adsorption performance in environmental remediation.

Ultrasound-assisted heterogeneous process for organic dye pollutants destruction using the novel MIL-101(Fe)/ZrO2/MnFe2O4 nanocomposite catalyst from water medium

Ultrasound-assisted heterogeneous process for organic dye pollutants destruction using the novel MIL-101(Fe)/ZrO2/MnFe2O4 nanocomposite catalyst from water medium

Microwave heating system for CuFe2O4/rGO/PMS enhanced catalytic-oxidative pre-treatment, water, and salt recovery from reverse osmosis reject of textile industry effluent

Microwave (MW) heating mechanism was investigated for reverse osmosis (RO) reject management of real textile effluent, i.e., pre-treatment, water, and salt recovery. For pre-treatment, microwave-induced catalytic degradation (MICD) enhanced with CuFe2O4/rGO for PMS activation was applied for organics degradation. The synthesized CuFe2O4/rGO (average particle size ∼16.44 nm) was characterized for XRD, SEM with EDAX, FTIR, VSM and TGA. MICD (1 g/L catalyst (80 %:20 %), 400 mg/L PMS, 90℃ MW temperature, 450 W MW power, and pH 11.32) showed 100 % color, 80.4 % TOC, and 91.1 % COD reduction within 16 min of MW irradiation. Radical quenching studies and EPR analysis revealed that SO4•− and ⦁OH were the dominant reactive species followed by non-radical O21. Recyclability study of CuFe2O4/rGO showed 72 % color, 65 % TOC, and 71.4 % COD removal after 5 cycles. XRD and FTIR of reused CuFe2O4/rGO hold similar crystallinity and structural properties as fresh catalyst. ATR-FTIR spectrum of before and after degradation of RO reject showed considerable degradation of organic dye molecules. Subsequently, the MW heating system was optimized for water recovery (110℃ MW temperature, 700 W MW power, and 100 mL reject volume), showing 100 % water recovery within 6 min, and its characterization showed a high distillate purity. NaCl and Na2SO4 salts were recovered under different MW operating temperatures, exploiting solubility equilibrium, and characterized for XRD, SEM with EDAX, and PSA.

Congo red dye reduction mediated by the electron (e−) transfer route of BH4 − ions using synthesized NiCo2O4/rGO hybrid nanosheets

The treatment of toxic organic pollutants is extremely important for the conservation of clean air, soil, and water. In this study, (reduced graphene oxide) NiCo2O4/ rGO hybrid nanocomposite was prepared by a facile hydrothermal technique and employed for organic dye adsorption from wastewater. The synthesized NiCo2O4/rGO hybrid nanocomposite was studied using FTIR, XRD, SEM, TEM, BET, Raman spectroscopy, and UV–visible. The physical characterizations prove the deposition of NiCo2O4 particles on the rGO surface. The transmission electron microscope image demonstrated that the NiCo2O4 particles with an average size of ∼46 nm was dispersed on the rGO surface. The obtained nanoparticles show a higher specific surface area of 56.4 m2 g−1. Adsorption dynamics as investigated by time and concentration variation show that the adsorption data follows pseudosecond order kinetics and the Langmuir isotherm model, with a maximum adsorption capacity of 106.2 mg g−1, indicating homogeneous physiochemical adsorption of CR dye on the adsorbent surface. Besides, the catalytic effectiveness of synthesized nanocomposite towards Congo red (CR) dye reduction mediated by the electron (e−) transfer route of BH4 − ions was explained in detail. The electrostatic interaction used between the NiCo2O4/rGO hybrid composite and Congo red increased the adsorption ion effectiveness of the dye sample.

Assessment of visible light sensitive La-doped BiOBr/ZnO for the effective degradation of malachite green dye

Environmental scientists across the globe are actively focused on developing novel materials to remove hazardous wastes from aqueous environments. Among the several methods available, photocatalysis stands out as a very efficient and environmentally beneficial process for removing organic dyes from wastewater. The present work involved the successful fabrication of lanthanum-doped bismuth oxy bromide/zinc oxide (La-doped BiOBr/ZnO, LBZ) as a photocatalyst through a facile hydrothermal technique. The synthesized LBZ composite exhibited enhanced photocatalytic degradation efficiency towards the malachite green (MG) dye molecules under visible light. The synthesized materials were characterized by different analytical techniques like FTIR, XRD, SEM, EDX, XPS, LC-MS, UV–Vis DRS, PL spectra, and mapping analysis, respectively. Various contributing factors, including irradiation time, solution pH, catalyst dosage, and initial dye concentration, were optimized using the batch mode for the maximum efficiency of the prepared catalyst. The prepared LBZ exhibited a bandgap energy of 2.78 eV as determined through UV–Vis DRS analysis. Among the prepared series of catalysts, the LBZ composite could degrade 99 % MG with a minimum irradiation time of 50 min under visible light irradiation. The involvement of h+ and O2− radicals proved to be significant during the degradation process of MG. Additionally, a proposed mechanism for the effective degradation of the photocatalytic degradation of MG was discussed, and successfully identified the mechanism pathway of MG was by employing LC-MS analysis. This investigation highlights the potential of prepared LBZ composite as an effective photocatalyst for removing toxic dye molecules commonly present in industrial effluents.

A Cu-based metal-organic frameworks-modified BiOCl heterojunction for enhanced photodegradation of rhodamine B

Environmental pollution caused by organic dyes has attracted increasing attention and prompts people to develop an effective treating method. Photocatalysis isregarded as one of the most promising treatment methodsowing to low cost, flexibility, and high efficiency. Herein, we reported a copper-based metal–organic frameworks (Cu-MOF) modified BiOCl heterojunction Cu-MOF/BiOCl (CMB) to treat organic dye rhodamine B (RhB) under white light illumination. The optimal photodegradation efficiency is shown to be 97 % within 40 min, exhibiting a higher photocatalytic ability than individual BiOCl and Cu-MOF. The enhanced photocatalytic activity is attributed to the formation of CMB heterojunction improving the visible light utilization efficiency and promoting significantly the separation/transfer of carriers. This study highlights the importance of combining narrow band gap nanomaterial with wide counterpart in environmental remediation.

CD-MOF-1 Growth on Polysaccharide Gels through Only C2-OH/C3-OH or C5-O/C6-OH Group Formed Four-Coordinated K+ Ions for Developing Porous Biogels.

The γ-cyclodextrin (γ-CD) metal-organic frameworks (CD-MOF-1) consist of γ-CD and potassium (K+) ions through coordinating an eight-coordinated K+ ion with two C5-linked oxygen and C6-linked hydroxyl (C5-O/C6-OH) groups in the primary faces of adjacent γ-CD units and two C2- and C3-linked hydroxyl (C2-OH/C3-OH) groups in the secondary faces. Herein, we found polysaccharide gels with only C2-OH/C3-OH or C5-O/C6-OH groups in pyranoid rings can form four-coordinated K+ ions and then coordinate γ-CD in a KOH solution for CD-MOF-1 growth. Exposure of C2-OH/C3-OH or C5-O/C6-OH groups in polysaccharide gels is important to form active four-coordinated K+ ions. Mechanism supporting this work is that four-coordinated K+ ion sites are first formed after coordinating C2-OH/C3-OH groups in pectin and then coordinating C5-O/C6-OH groups in the primary faces of γ-CD units. Alternatively, four-coordinated K+ ions with C5-O/C6-OH groups in chitosan can coordinate the C2-OH/C3-OH groups in the secondary faces of γ-CD units. Mechanism of CD-MOF-1 growing on pectin and chitosan gels through the proposed four-coordinated K+ ions is also universally applicable to other polysaccharide gels with similar C2-OH/C3-OH or C5-O/C6-OH groups such as alginate gel. Based on this mechanism, we developed pectin and chitosan gel-based CD-MOF-1 composites and exemplified applications of them in antibacterial and organic dye removal. To help future research and applications of this mechanism, we share our theoretical assumption for further investigations that any matrices with an ortho-hydroxyl carbon chain or ortho-hydroxyl ether structures may form four-coordinated K+ ions for CD-MOF-1 growth. The proposed mechanism will broaden the development of novel CD-MOF-1 composites in various fields.

Terpyridine complexes as superior catalysts for methylene blue dye degradation: Synthesis, characterization, mechanistic insights, kinetic study and recyclability assessment

This manuscript investigates the catalytic potential of terpyridine-based metal complexes (C1–C6) in the efficient degradation of methylene blue dye. The synthesized terpyridine complexes were characterized using various spectroscopic techniques, and their catalytic activity was evaluated in the degradation of methylene blue dye under different experimental conditions. The study reveals that the target complex compounds exhibit notable catalytic efficiency, leading to the effective degradation of the envisioned dye. The reaction kinetics, mechanism, and the influence of various parameters on the catalytic performance were systematically explored. Among different synthesized complexes, Zn-complexes showed better performance than Fe-complexes. Remarkably, the complex C5 showed the best photocatalytic efficiency with a degradation of 79.84 % at optimized conditions of initial dye concentration = 15 mg/L, catalyst dosage = 10 mg, pH = 4, and temperature = 323 K. The recyclability test indicated good stability of the photocatalyst over five cycles with a very small loss of photocatalytic efficiency (∼11.64 %) and the photocatalytic reaction followed pseudo-first order kinetics with a high-rate constant of 0.009 min−1. The trapping experiment revealed the active role of hydroxyl radicals (OH•) and superoxide anions (•O2−) as reactive species on the basis of which a plausible degradation mechanism is proposed. This research contributes valuable insights into the development of terpyridine-based catalysts for the degradation of organic dyes, paving the way for further advancements in the field of catalysis and environmental remediation.

Photochemical optimization of fluorescent dye-doped PDMS for enhanced luminescent solar concentrator performance

Luminescent solar concentrators (LSCs) that incorporate organic dyes face challenges such as self-absorption loss and aggregation-caused quenching (ACQ) as doping concentration increases, limiting the dye loading capacity. Particularly for dyes with a small Stokes shift, losses due to self-absorption or quenching are prominent even at low concentrations, hindering the attainment of high power conversion efficiency (PCE) in LSCs. Additionally, exposure of the dye-impregnated polymer matrix to oxygen, moisture, UV light, and other factors leads to a decrease in luminescence efficiency and stability due to the photooxidation reaction of the phosphor. This study presents a facile approach for enhancement of the efficiency and environmental stability of coumarin 6 (C6) dye-doped polydimethylsiloxane (PDMS) LSC through ultraviolet ozone (UVO) treatment. Photocleavage of the C6 dimer into a C6 monomer through UVO treatment leads to a significant enhancement in luminescence. Additionally, thin SiOx layers formed on both sides of the LSC not only assist in capturing luminescent light more efficiently but also block the penetration of oxygen and moisture into the LSC, resulting improved device stability. UVO-treated LSC shows approximately 32 % improvement in PCE compared to bare LSCs and exhibits significantly better stability during the 30-day long-term performance test.

NiO@PANI based Nanocomposites as an Advanced Functional Material: Experimental and Computational Approach

Background:: Individually, metal nanoparticles (NPs) and conducting polymers show unique properties due to small size, large surface area, and high order of conductivity. But their combination may result in a synergistic effect in properties. Methods:: The NiO NPs and conducting polymer Polyaniline were prepared by modified Sol-gel and chemical oxidative methods, respectively. Powder XRD, FTIR, TEM, and UV-visible methods were used for the structural evaluation. The computational (DFT) study was performed to support experimental results. The NiO/Polyaniline (PANI) nanocomposites (NCs) were explored as corrosion inhibitors, electrical conductors, and photocatalytic agents. Results:: The NiO/Polyaniline NCs showed 91.52% corrosion inhibition efficiency at 1000 ppm concentration. The photocatalytic activity was investigated against methylene blue dye under ultraviolet light. The NiO/Polyaniline NCs decompose 90% of organic dye. The NCs exhibit good conducting, corrosion inhibition, and photocatalytic activity. Conclusion:: The metal oxide (NiO NPs) and PANI-based NCs can be used as corrosion inhibitors, conducting material, and for the degradation of organic compounds (dyes) in impure water.