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A new generation of metal-free organic dyes with a range of donor (D1) and acceptors (A1-A3) were designed and examined for dye-sensitized solar cells (DSSCs) based on (3a) dye as a literature. Triphenylamine (TPA), thiophene (π) and 2-cyanoacrylic acid groups each perform the roles of an acceptor (A), donor (D) and spacer in order to produce a D- π -A system. To investigate the intramolecular charge transfer (ICT), electronic distribution, ultra-violet visible (UV–Vis) absorption wavelengths, molecular electrostatic potential (MEP) and photovoltaic (PV) parameters of the D1 and A1–A3 molecules, density functional theory (DFT) and time-dependent DFT (TD-DFT) were used. The classification of the tunable donor D1 and A1–A3 determines the PV performance of the dye molecules. Results show that the A2 dye replacement group increases the performance of PV cells via red-shifting absorption spectra. Also, when compared to 3a, A2 dye have lower energy gap ( E g) and superior UV–Vis spectra that cover the full visible range. These results demonstrate the viability of molecular tailoring as an approach to improve D- π -A sensitizer proposal for efficient DSSCs fabrication. Perylene-based organic dyes (D1 and A1–A3) are designed and systematically investigated for DSSCs. To investigate the intramolecular charge transfer (ICT), electronic distribution, ultra-violet visible (UV–Vis) absorption wavelengths and photovoltaic (PV) parameters of the D1 and A1–A3 molecules, density functional theory (DFT) and time-dependent DFT (TD-DFT) were used. All the dyes might be used for the potential in DSSCs. [ABSTRACT FROM AUTHOR]

This comprehensive review investigates the potential of aluminum oxide (Al2O3) as a highly effective adsorbent for organic dye degradation. Al2O3 emerges as a promising solution to address environmental challenges associated with dye discharge due to its solid ceramic composition, robust mechanical properties, expansive surface area, and exceptional resistance to environmental degradation. The paper meticulously examines recent advancements in Al2O3-based materials, emphasizing their efficacy in both organic dye degradation and adsorption. Offering a nuanced understanding of Al2O3's pivotal role in environmental remediation, this review provides a valuable synthesis of the latest research developments in the field of dye degradation. It serves as an insightful resource, emphasizing the significant potential of aluminum oxide in mitigating the pressing environmental concerns linked to organic dye discharge. The application of Al2O3-based catalysts in the photocatalytic treatment of multi-component organic dyes necessitates further exploration, particularly in addressing real-world wastewater complexities. [ABSTRACT FROM AUTHOR]

The development of photocatalysts for organic degradation is a hot research topic. In this study, CdZnS was selected as the carrier, and ZIF-8 was combined with it to explore the photocatalytic performance of the composite. In addition, the compound material, CdZnS@ZIF-8, was used as a photocatalyst for the decomposition of methylene blue dye, and the performance of pure CdZnS and pure ZIF-8 was compared. The photocatalytic efficiency of CdZnS@ZIF-8 was significantly higher than that of the other two. In the experimental reaction, the amount of catalyst was 0.04 g, the pH value was 7, the initial concentration of methylene blue aqueous solution was 20 mg/L, and the degradation of methylene blue in 50 mL aqueous solution could reach 99.5% under visible light irradiation for 90 min, showing excellent photocatalytic efficiency in the visible light range. It demonstrated excellent photocatalytic function in the visible light region, and the electron transfer phenomenon at the interface occurred in the het-junction and the separation of the photo-generating electron–hole as an electron acceptor of ZIF-8 further promoted the photocatalytic effect. [ABSTRACT FROM AUTHOR]

The modification of the Tetraselmis sp. algae material (Tetra-Alg) with surfactant Cethyltrimethylammonium Bromide (CTAB) yielded adsorbent Tetra-Alg-CTAB as an adsorbent of methyl orange (MO) and methylene blue (MB) solutions. The characterization of the adsorbent used an infrared (IR) spectrometer to identify functional groups and Scanning Electron Microscopy with Energy Dispersive X-ray (SEM-EDX FEI Inspect-S50, Midland, ON, Canada) to determine the surface morphology and elemental composition. Methyl orange and methylene blue adsorption on the adsorbent Tetra-Alg, Tetraselmis sp. algae-modified Na+ ions (Tetra-Alg-Na), and Tetra-Alg-CTAB were studied, including variations in pH, contact time, concentration, and reuse of adsorbents. The adsorption of MO and MB by Tetra-Alg-CTAB at pH 10, during a contact time of 90 min, and at a concentration of 250 mg L−1 resulted in MO and MB being absorbed in the amounts of 128.369 and 51.013 mg g−1, respectively. The adsorption kinetics and adsorption isotherms of MO and MB and Tetra-Alg, Tetra-Alg-Na, and Tetra-Alg-CTAB tend to follow pseudo-second-order kinetics models and Freundlich adsorption isotherms with each correlation coefficient value (R2) approaching 1. Due to the modification with the cationic surfactant CTAB, anionic dyes can be strongly sorbed in alkaline pH due to strong electrostatic attraction, while MB is more likely to involve cation exchange and hydrogen bonding. The reuse of Tetra-Alg-CTAB was carried out four times with adsorption percent > 70%, and the adsorbent was very effective in the adsorption of anionic dyes such as MO. [ABSTRACT FROM AUTHOR]

New organic dyes (H1-H6) for their promising applications as dye sensitized solar cell (DSSCs) were theoretically designed from 6,6′-di(thiophen-2-yl)-4,4′-bipyrimidine (TB) moiety in acceptor (A), π-spacer, and donor (D) type architecture to create A-π-D-π-D-π-A framework. After their benchmarking study against various exchange correlation (XC) and long-range corrected (LC) functional, the CAM-B3LYP produced accurate results so as selected for further density functional theory (DFT) and time dependent DFT (TD-DFT) studies. The frontier molecular orbitals (FMOs) were analyzed for their electron transfer properties, and their energies of the highest occupied molecular orbital (EHOMO) and the lowest unoccupied molecular orbital (ELUMO) were used to assess various electronic properties. Their energy differences (EH-L) ranged between 1.69 and 2.03 eV indicating their good responsiveness to electron injection (Ginj) being the values greater than 0.2 eV. The maximum absorbance of the dyes was reported around the 388–406 nm while their starting material (TB) had this value to be 371 nm. This redshift was significant with an intensification of electron-withdrawing groups on the dye structures. The dyes were evaluated for their device related parameters like their light harvesting efficiency, open circuit voltage, exciton binding energies, and exciton life times which were found in their promising values. The dyes were analyzed for their linear (α), first (βtotal), and second (γtotal) order nonlinear responses and were found to have significantly higher responses, not only against their starting materials but also those reported in literature for standard molecules (urea and p-nitric acid). Among the dyes under study, dye H4 exhibits the highest molecular polarizability (α) and hyperpolarizability (β and γ) values thanks to two CN substituted units on each ends. These dyes are most likely to have possible optical and photonic uses. Also, according to the results of the current theoretical research, all of these dyes may function as effective photosensitizer for their DSSC application. [ABSTRACT FROM AUTHOR]

Organic dyes based on chlorophyll derivatives were synthesized and investigated with respect to applications in dye sensitized solar cells (DSSC). Cyanobacterium Spirulina platensis cultivated on large scales in tropical areas around the Pacific Ocean is an attractive source for production and isolation of pure chlorophyll a. Direct transformation of chlorophyll a into very robust chlorin e6 trimethylester 3 affords an ideal platform for synthesis of dyes for artificial photosynthesis. A series of molecules 24–32 with donor‐π‐acceptor structures and functional groups for immobilization on TiO2 were achieved by subsequent synthetic modifications of 3. Photochemical, theoretical and electrochemical properties of dyes were investigated and their sensitized solar cells performances studied after immobilization on TiO2. [ABSTRACT FROM AUTHOR]

The present study is an endeavour to document the pattern of comparative advantage and structural changes of Indian exports with Africa with the help of revealed comparative advantage index and the constant market share model for the period 1980–2021. The results indicate that India possesses a comparative advantage in a large number of export products to markets in Africa. However, most of these exports belong to the category of low-tech and resource-based goods. Considering its abundant labour, it is to be expected for India to have a comparative advantage in these low-skilled and labour-intensive traditional exports. The commodities with maximum advantage in the African market are medicinal and pharmaceutical products followed by sugar, sugar preparations, and honey. In the category of technology-intensive products, India has strengthened its market power only in the export of organic chemicals and dyes, and colouring materials. [ABSTRACT FROM AUTHOR]

We here report the synthesis, characterization, and catalytic performance of new supported Pd(0) catalysts. The catalysts were characterized by SEM, TEM, XRD, FT-IR, VSM, XPS, TG and AAS. The results showed that the catalyst exhibited good catalytic activity in the reaction of degradation of 4-NP and organic dyes MO and MB in water with NaBH4 and amino borane (AB) as the hydrogen sources. At the same time, the catalyst has good recoverability and is easily recovered and recycled from the reaction mixture by applying an external magnet and reusing it in five cycles without significant loss in activity. In the present work, our deliberately designed experiments demonstrate that Ni@Pd immobilized on the surface of hollow Fe3O4@PPy-Gly (HFPG) under mild condition. It exhibits high activity for the reduction of 4-NP and organic dyes by NaBH4 and AB. [ABSTRACT FROM AUTHOR]

Fluorescent materials with high brightness play a crucial role in the advancement of various technologies such as bioimaging, photonics, and OLEDs. While significant efforts are dedicated to designing new organic dyes with improved performance, enhancing the brightness of existing dyes holds equal importance. In this study, we present a simple supramolecular strategy to develop ultrabright cyanine‐based fluorescent materials by addressing long‐standing challenges associated with cyanine dyes, including undesired cis‐trans photoisomerization and aggregation‐caused quenching. Supra‐cyanines are obtained by incorporating cyanine moieties in a cyclic peptide‐based supramolecular scaffold, and exhibit high fluorescence quantum yields (up to 50 %) in both solution and in the solid state. These findings offer a versatile approach for constructing highly emissive cyanine‐based supramolecular materials. [ABSTRACT FROM AUTHOR]

Fluorescent materials with high brightness play a crucial role in the advancement of various technologies such as bioimaging, photonics, and OLEDs. While significant efforts are dedicated to designing new organic dyes with improved performance, enhancing the brightness of existing dyes holds equal importance. In this study, we present a simple supramolecular strategy to develop ultrabright cyanine‐based fluorescent materials by addressing long‐standing challenges associated with cyanine dyes, including undesired cis‐trans photoisomerization and aggregation‐caused quenching. Supra‐cyanines are obtained by incorporating cyanine moieties in a cyclic peptide‐based supramolecular scaffold, and exhibit high fluorescence quantum yields (up to 50 %) in both solution and in the solid state. These findings offer a versatile approach for constructing highly emissive cyanine‐based supramolecular materials. [ABSTRACT FROM AUTHOR]

Traditional water-soluble organic macrocyclic receptors generally lack photofunctionality, thus monitoring the drug delivery and the phototheranostic applications of these host–guest macrocyclic systems has been greatly restricted. To address this issue, incorporating π-conjugated dye chromophores as building blocks into macrocyclic molecules is a straightforward and promising strategy. This approach not only imparts intrinsic optical features to the macrocycles themselves but also enhances the host–guest binding ability due to the large planar structures of the dyes. In this feature article, we focus on recent advances in water-soluble macrocyclic compounds based on organic dye chromophores, such as naphthalimide (NDI), perylene diimides (PDI), azobenzene (azo), tetraphenylethylene (TPE) and anthracene, and provide an overview of their various applications including molecular recognition, drug release, biological imaging, photothermal therapy, etc. We hope that this article could be helpful and instructive for the design of water-soluble dye-based macrocycles and the further development of their biomedical applications, particularly in combination with drug therapy and phototheranostics. [ABSTRACT FROM AUTHOR]

In this paper, we employ density functional theory (DFT) simulations to predict the energy conversion efficiency of a novel class of organic dyes based on linear carbon chain (LCC) linkers for application in dye-sensitized solar cells (DSSCs). We investigate the role of the anchoring group, which serves as a bridge connecting the linker and the surface. Specifically, we compare the performance of cyanoacrylic acid, dyes PY-4N and PY-3N, with that of phosphonate derivatives, dyes PY-4NP and PY-3NP, wherein the carboxylic group of the cyanoacrylic moiety is replaced with phosphonic acid. The observed variations in the UV/VIS absorption spectra have a slight impact on the light harvesting efficiency (LHE). Based on the empirical parameters we have taken into account, the electron injection efficiency (Φinj) and electron collection efficiency (ηcoll) values do not impact the short-circuit current density (JSC) values of all the studied dyes. The open-circuit voltage (Voc) is theoretically predicted using the improved normal model (INM) method. Among the dyes, PY-4N and PY-3N demonstrate the highest Voc values. This can be attributed to a more favorable recombination rate value, which is related to the energy gap between the HOMO level of the dyes and the conduction band minimum (CBM) of the surface. Dyes PY-4N and PY-3N are predicted to demonstrate remarkably high photoelectric conversion efficiency (PCE) values of approximately 21.79% and 16.52%, respectively, and therefore, they are expected to be potential candidates as organic dyes for applications in DSSCs. It is worth noting that PY-4NP and PY-3NP exhibit strong adsorption energy on the surface and interesting PCE values of 11.66% and 8.29%, respectively. This opens up possibilities for their application in DSSCs either as standalone sensitizers or as co-sensitizers alongside metal-free organic dyes or organic–inorganic perovskite solar cells. [ABSTRACT FROM AUTHOR]

In this study, we used solvent assisted mechano-synthesis strategies to form multifunctional organic–inorganic nanocomposites capable of removing both organic and inorganic contaminants. A zeolite X (Ze) and activated carbon (AC) composite was synthesized via state-of-the-art mechanical mixing in the presence of few drops of water to form Ze/AC. The second composite (Ze/L/AC) was synthesized in a similar fashion, however this composite had the addition of disodium terephthalate as a linker. Both materials, Ze/AC and Ze/L/AC, were characterized using scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Powdered X-ray diffraction (P-XRD), Fourier-transform infrared spectrometry (FTIR), Accelerated Surface Area and Porosimetry System (ASAP), and thermal gravimetric analysis (TGA). The SEM–EDS displayed the surface structure and composition of each material. The sodium, oxygen and carbon contents increased after linker connected Ze and AC. The P-XRD confirmed the crystallinity of each material as well as the composites, while FTIR indicated the function groups (C=C, O–H) in Ze/L/AC. The contaminant adsorption experiments investigated the effects of pH, temperature, and ionic strength on the adsorption of methylene blue (MB) and Co(II) for each material. In MB adsorption, the first-order reaction rate of Ze/L/AC (0.02 h−1) was double that of Ze/AC (0.01 h−1). The reaction rate of Ze/L/AC (4.8 h−1) was also extraordinarily higher than that of Ze/AC (0.6 h−1) in the adsorption of Co(II). Ze/L/AC composite achieved a maximum adsorption capacity of 44.8 mg/g for MB and 66.6 mg/g for Co(II) ions. The MB adsorption of Ze/AC and Ze/L/AC was best fit in Freundlich model with R2 of 0.96 and 0.97, respectively, which indicated the multilayer adsorption. In the Co(II) adsorption, the data was highly fit in Langmuir model with R2 of 0.94 and 0.92 which indicated the monolayer adsorption. These results indicated both materials exhibited chemisorption. The activation energy of Ze/L/AC in MB adsorption (34.9 kJ mol−1) was higher than that of Ze/L/AC in Co (II) adsorption (26 kJ mol−1). [ABSTRACT FROM AUTHOR]

A novel, magnetic HKUST-1 MOF based on MgFe2O4-NH2 was designed and synthesized in two steps and applied effective removal of malachite green (MG), crystal violet (CV), and methylene blue (MB) from water samples. Characterization of the newly synthesized MgFe2O4-NH2-HKUST-1 was performed by various techniques such as Fourier transform infrared spectroscopy, X-ray diffraction, Field emission scanning electron microscopy, Brunauer–Emmett–Teller, Thermal gravimetric analysis, and Vibration sampling magnetometry. Malachite green, crystal violet and methylene blue are toxic and mutagenic dyes that can be released into the water in different ways and cause many problems for human health and the environment. The removal of malachite green, crystal violet, and methylene blue from aqueous solutions was investigated using the magnetic HKUST-1 in this research. The effect of various parameters such as pH, amount of sorbent, dye concentration, temperature, and contact time on dye removal has been studied. The results showed that more than 75% of dyes were removed within 5 min. Adsorption isotherms, Kinetic, and thermodynamic studies were investigated. The results of this study show that adsorption capacity of the magnetic adsorbent is equal to 108.69 mg g−1 for MG, 70.42 mg g−1 for CV, and 156.25 mg g−1 for MB. This study shows the good strategy for the synthesis of the functionalized magnetic form of HKUST-1 and its capability for increasing the efficiency of the removal process of malachite green, crystal violet, and methylene blue from an aqueous solution. [ABSTRACT FROM AUTHOR]

Industrial effluents are a leading major threat for water contamination, subsequently which results in severe health associated risks. Hence, purifying wastewater before releasing into the water resources is essential to avoid contamination. In this study, ZnO/Cu-DPA nano-composites were prepared by altering the percentage of Cu-DPA (20%, 30%, 40%, and 50% which are denoted to be ZnO/20%Cu-DPA, ZnO/30%Cu-DPA, ZnO/40%Cu-DPA and ZnO/50%Cu-DPA) using a simple mechanical grinding process. Several spectroscopic studies were employed such as electron paramagnetic analysis (EPR), powdered X-ray diffractometer (PXRD), UV–Vis absorbance spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscope to characterize these nano-composites. The photo-catalytic activities of the prepared nano-composites were studied by degrading MB under visible light irradiation. ZnO, ZnO/20%Cu-DPA, ZnO/30%Cu-DPA, ZnO/40%Cu-DPA and ZnO/50%Cu-DPA degradation efficiencies were determined to be 71.8, 78.5, 77.1, and 66.1%, respectively. Among the composite catalysts, the ZnO/20%Cu-DPA coupled system are demonstrated the best efficiency (87%) for photo-degradation of MB within 80 min when exposed to visible light. The ZnO/Cu-DPA nano-composites had a greater MB photodegradation efficiency than pristine ZnO owing to p-n heterojunction in the linked system. Under visible light irradiation, the ZnO/20%Cu-DPA catalysed the conversion of dissolved O2 to hydroxyl radicals (OH·), triggering the reduction of MB. This suggests that ·OH is the primary specific active radical involved in the photo-catalytic decomposition of MB. Furthermore, EPR analysis indicates the existence of ·OH in the photo-catalytic system. The proposed nano-composites (ZnO/20%Cu-DPA) reusability was investigated across three cycles as the most efficient photo-catalyst. The results show that, the ZnO/Cu-DPA nano-catalyst is a potential candidate for the remediation of dirty water. [ABSTRACT FROM AUTHOR]

In this study, we present a novel method for immobilizing Palladium nanoparticles (Pd NPs) onto a polydimethylsiloxane (PDMS) support (Pd NPs@PDMS). To enhance the stability of Pd NPs on the PDMS surface, we functionalized a PDMS thin film with amine groups. The structure and morphology of the resulting Pd NPs@PDMS material were characterized using various techniques, including field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and X‐ray photoelectron spectroscopy (XPS) measurements. Furthermore, we investigated the catalytic performance of the Pd NPs@PDMS nanocatalyst for the reduction of well‐known environmental pollutants, such as 4‐nitrophenol (4‐NP), 2‐nitrophenol (2‐NP), 4‐nitroaniline (4‐NA), Methyl Orange (MO), Methylene Blue (MB), and Congo Red (CR), in the presence of sodium borohydride (NaBH4) at room temperature (RT). Additionally, we explored the application of the prepared nanocatalyst in carbon‐carbon (C−C) coupling reactions, specifically Suzuki Miyaura and Sonogashira reactions. The results obtained in this study demonstrated the high efficiency and environmentally friendly nature of Pd NPs@PDMS as a catalyst for both C−C coupling reactions and the degradation of organic pollutants. [ABSTRACT FROM AUTHOR]

The preparation of high performance, low cost and recyclable adsorbents is very important to cope with the increasingly devastating water pollution. As a typical three-dimensional porous carbon material, carbon foam (CF) is expected to be a highly efficient adsorbent to wipe out organic dyes from wastewater. However, the uneven size distribution, and lack of adsorption sites signified by insufficient foaming process limit its wider application in the environmental field. Here, CF/carbon nanotubes/graphene oxide (CF/CNTs/GO) composites (adsorbents) were prepared by press-assisted foaming and carbonization methods using mesophase precursors of coal tar pitch and CNTs followed by impregnation of GO nanosheets. The results highlighted that the addition of CNTs facilitated improvement in pore distribution, porosities, and mechanical properties (20 MPa). After treating with GO nanosheets, the adsorption performances of CF/CNTs/GO adsorbents substantially improved due to the increased active sites in the CF/CNTs and the adsorption rate and capacity of methylene blue (MB) reached 73.1% and 146 mg/g respectively. Further, adsorption isotherms (Langmuir and Freundlich), thermodynamics, quasi-first order and quasi-second order kinetics and intraparticle diffusion models were employed to investigate the adsorption mechanism. This work provides a low-cost fabrication technique for the high-performance CF/CNTs/GO adsorbent and is expected to provide reference for application in the treatment of contaminated water. [ABSTRACT FROM AUTHOR]

Stress-induced polarization is deemed to be an important avenue for enhancing photocatalytic activity of photocatalysts, which has drawn considerable attention recently. In this report, we have experimentally and theoretically studied the piezoelectricity-enhanced photocatalytic activity and involved mechanism of Bi 2 MoO 6 nanosheets derived via a hydrothermal synthesis route. Simulated sunlight, ultrasonic and both of them were used to drive the photocatalysis, piezocatalysis and piezo-photocatalysis, respectively. It is demonstrated that, for degradation of various organic dyes and antibiotics, the Bi 2 MoO 6 nanosheets manifest a piezo-photocatalytic activity obviously larger than single photocatalytic activity and piezocatalytic activity with synergistic factor SF > 1. The piezoelectricity in the Bi 2 MoO 6 nanosheets and its enhanced photocatalytic mechanism were elucidated through density functional theory (DFT) calculations combined with finite-element method (FEM) simulations. Additionally, taking the typical organic dye — methylene blue (MB) as an example, we have also investigated the effects of various factors on its degradation efficiency, degradation pathways and mechanism, as well as toxic assessment of degradation by-products. [ABSTRACT FROM AUTHOR]

Environmental issues have always been a concern, and designing a material that can effectively combat both gaseous and liquid pollutants is a goal we are working toward. Herein, two examples of N-rich covalent organic frameworks (COFs), named YCOF1 and YCOF2, were synthesized using the solvothermal method. Their structure, stability and morphology were characterized using PXRD, FT-IR, XPS, TGA and SEM. According to the Brunauer–Emmett–Teller (BET) method, the specific surface areas of YCOF1 and YCOF2 were 559.096 and 741.261 m2 g−1, respectively. Under the volume percentage of simulated flue gases, YCOF1 exhibits excellent CO2 IAST selectivities of 70.97 at 273 K and 30.05 at 298 K, while YCOF2 also exhibits excellent CO2 IAST selectivity of 51.90 at 273 K. Moreover, their high specific surface area and abundant active sites provide excellent adsorption capacity for malachite green (MG), with maximum adsorption amounts of 650.14 mg g−1 (YCOF1) and 572.95 mg g−1 (YCOF2). Furthermore, the adsorption of the COFs for dyes followed the pseudo-second-order kinetic model and the Langmuir isothermal adsorption model. The dye removal efficiency of YCOF1 and YCOF2 showed less than 5% change after 5 adsorption cycles. [ABSTRACT FROM AUTHOR]

Organic dyes hold great promise for application in photodynamic therapy (PDT). However, they currently face challenges such as inadequate photodynamic activity, limited tumor penetration, and constraints imposed by tumor hypoxia. Here, a facile and efficient strategy is presented for multi‐enhanced PDT through the fluorination of a squarylium indocyanine dye‐based photosensitizer (FCy). The amphiphilic FCy features perfluorooctane and PEG‐biotin moieties conjugated to a squarylium indocyanine core. In aqueous environments, FCy spontaneously self‐assembles into stable nano‐sized photosensitizers (FCy NPs), demonstrating a high oxygen loading ability attributable to the presence of perfluoroalkyl groups. Consequently, the aggregation of squarylium indocyanine dyes remarkably boosts the photodynamic effect, yielding a 15‐fold improvement in singlet oxygen quantum yield. Owing to the perfluoroalkyl group, FCy NPs exhibit increased endoplasmic reticulum (ER)‐ accumulating abilities, which further induce ER stress upon laser irradiation and enhance the PDT effect. Furthermore, the superior deep tumor penetration ability of FCy NPs is confirmed through both in vitro and in vivo studies. With efficient oxygen supply to the deep tumor regions, FCy NPs demonstrate potent imaging‐guided PDT against hypoxia tumors. The study substantiates the enhanced ER‐accumulating ability of the perfluoroalkyl group and presents a facile fluorination strategy for the multi‐enhancement of photosensitizers. [ABSTRACT FROM AUTHOR]

Instrumental techniques able to identify and structurally characterize the aggregation states in thin films of chiral organic π‐conjugated materials, from the first‐order supramolecular arrangement up to the microscopic and mesoscopic scale, are very helpful for clarifying structure‐property relationships. Chiroptical imaging is currently gaining a central role, for its ability of mapping local supramolecular structures in thin films. The present review gives an overview of electronic circular dichroism imaging (ECDi), circularly polarized luminescence imaging (CPLi), and vibrational circular dichroism imaging (VCDi), with a focus on their applications on thin films of chiral organic dyes as case studies. [ABSTRACT FROM AUTHOR]

From the perspective of environmental protection, the highly efficient degradation of antibiotics and organic dyes in wastewater needs to be tackled as soon as possible. In this study, an ecofriendly and green cube-shaped cobalt-doped zinc oxide nanoparticles (Co–ZnO NPs) photocatalyst using Pterocladia Capillacea (P. Capillacea) water extract loaded with 5, 10, and 15% cobalt ions were formed via co-precipitation process to degrade antibiotics. The prepared Co–ZnO NPs were tested as a photocatalyst for the photodegradation of ciprofloxacin (CIPF) in the presence of a visible LED-light source. Co–ZnO NPs have been obtained through the co-precipitation method in the presence of P. Capillacea extract as a green capping agent and reducing agent, for the first time. Several characterization techniques including FTIR, XRD, BET, XPS, TEM, EDX, SEM, TGA and DRS UV–Vis spectroscopy were applied to study the prepared Co–ZnO NPs. XRD results suggested that the average size of these NPs ranged between 42.82 and 46.02 nm with a hexagonal wurtzite structure. Tauc plot shows that the optical energy bandgap of ZnO NPs (3.19 eV) gradually decreases to 2.92 eV by Co doping. Examinations showed that 5% Co–ZnO NPs was the highest efficient catalyst for the CIPF photodegradation when compared with ZnO NPs and other 10 and 15% Co–ZnO NPs. A 10 mg/L solution of CIPF was photo-degraded (100%) within the first 15 min irradiation. The kinetics showed that the first-order model is suitable for displaying the rate of reaction and amount of CIPF elimination with R2 = 0.952. Moreover, central composite design optimization of the 5% Co-doped ZnO NPs was also investigated. [ABSTRACT FROM AUTHOR]

Iron oxide and its carbon‐containing biochar have shown efficiencies in Fenton oxidation reactions in recent years. Though magnetic biochar composites have been reported, developing facile, environment‐friendly methods with appropriate activity remains challenging. Removing dye traces from aqueous solutions is a prime concern under water scarcity issues at different levels. We developed a catalyst of biochar with magnetite for dye remediation. Magnetite is homogeneously loaded on biochar surfaces to form Fe3O4‐biochar to efficiently activate H2O2 to achieve hydroxyl radicals. This catalyst degrades Fast green dye efficiently around 89.3 % within 60 min with the optimum reaction conditions of 15 mM Fast Green dye, pH=4, 30 mg of Fe3O4‐biochar and 25 mM of H2O2. The composite shows around 41 % increase in the degradation rate after incorporating the Fe3O4 on biochar. The prepared Fe3O4‐biochar composite can be easily recycled without significant activity loss for five successive degradation reactions. The reported study provided a direction to prepare newer Fenton catalysts from sustainable sources for the degradation of organic dyes in water and overcame individual limitations of Fe3O4 and biochar. [ABSTRACT FROM AUTHOR]

The advancement of fluorescence microscopy techniques has opened up new opportunities for visualizing proteins and unraveling their functions in living biological systems. Small‐molecule organic dyes, which possess exceptional photophysical properties, small size, and high photostability, serve as powerful fluorescent reporters in protein imaging. However, achieving high‐contrast live‐cell labeling of target proteins with conventional organic dyes remains a considerable challenge in bioimaging and biosensing due to their inadequate cell permeability and high background signal. Over the past decade, a novel generation of fluorogenic and cell‐permeable dyes has been developed, which have substantially improved live‐cell protein labeling by fine‐tuning the reversible equilibrium between a cell‐permeable, nonfluorescent spirocyclic state (unbound) and a fluorescent zwitterion (protein‐bound) of rhodamines. In this review, we present the mechanism and design strategies of these fluorogenic and cell‐permeable rhodamines, as well as their applications in bioimaging and biosensing. [ABSTRACT FROM AUTHOR]

Biochar is a potential porous carbon to remove the contaminants from aquatic environments. Herein, N-doped hierarchical biochar was produced by the combined approach of ammonia torrefaction pretreatment (ATP) and alkali activation. ATP could not only incorporate N element into poplar wood, but obtain the loose structure of poplar wood. The highest surface area of N-doped hierarchical biochar was 2324.61 m2 g−1 after ammonia wet torrefaction pretreatment, which was higher than that of activation carbon (1401.82 m2 g−1) without torrefaction pretreatment, the hierarchical biochar (2111.03 m2 g−1) without ammonia atmosphere. The N-doped hierarchical biochar presented the highest adsorption capacity (564.7 mg g−1) of methyl orange (MO), which was 14.64-fold of that on biochar without N doping. In addition, the pseudo-second-order and Langmuir model fitted well with the adsorption kinetics and isotherms of the N-doped hierarchical biochar. The incorporation of nitrogen element could not only tune the distribution of surface electrons on biochar, but optimize the ambient condition of adsorption active sites as well. The adsorption of MO might occur on the N-/O-containing functional groups through the electrostatic interaction, the π-π dispersion interaction, and the hydrogen bonding. The density functional theory showed that the graphitic-N and pyridinic-N were the dominant adsorption active sites. Highlights: Ammonia torrefaction pretreatment coupled with alkali activation was developed for the preparation of N-doped hierarchical biochar. AWTP had better performance on N-doping and increasing of BET than ADTP. Graphitic-N and pyridinic-N were dominant active sites for the adsorption of organic dye. [ABSTRACT FROM AUTHOR]

The advancement of fluorescence microscopy techniques has opened up new opportunities for visualizing proteins and unraveling their functions in living biological systems. Small‐molecule organic dyes, which possess exceptional photophysical properties, small size, and high photostability, serve as powerful fluorescent reporters in protein imaging. However, achieving high‐contrast live‐cell labeling of target proteins with conventional organic dyes remains a considerable challenge in bioimaging and biosensing due to their inadequate cell permeability and high background signal. Over the past decade, a novel generation of fluorogenic and cell‐permeable dyes has been developed, which have substantially improved live‐cell protein labeling by fine‐tuning the reversible equilibrium between a cell‐permeable, nonfluorescent spirocyclic state (unbound) and a fluorescent zwitterion (protein‐bound) of rhodamines. In this review, we present the mechanism and design strategies of these fluorogenic and cell‐permeable rhodamines, as well as their applications in bioimaging and biosensing. [ABSTRACT FROM AUTHOR]

The development of photocatalysis is hindered, in part, by the quick recombination of photogenerated carriers and the instability of light sources. In this study, the problem of too-fast electron–hole pair compounding in photocatalysis is effectively regulated by the polarization field of pyroelectric materials using the pyroelectric method. Self-polarized pyroelectric materials that depend on temperature variations can generate usable electrical energy and polarized charge carriers to degrade organic pollutants. Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN–PT) is a relaxor ferroelectric material with spontaneous polarization characteristics. The PMN–0.30PT:1 mol%Sm3+ catalyst was prepared by applying the high-temperature solid-state reaction method. Under the dark condition and nine cold–hot cycles of 23 °C–68 °C, using H2O2-assisted PMN–0.30PT:1 mol%Sm3+ as a catalyst, the degradation rate of rhodamine 6G (10 mg L−1) was 94.3 ± 2.5%. In addition, the degradation rates of 88.52% and 64.32% were obtained for rhodamine B (10 mg L−1) and methylene blue (10 mg L−1), respectively. This study provides a new approach to the pyroelectric catalytic degradation of organic pollutants. [ABSTRACT FROM AUTHOR]

In this study, a new cobalt-based metal–organic framework (JLNU-500), [Co2(OH)(PBA)(AIP)]·3DMA·0.75H2O (4-(pyridin-4-yl) benzoic acid (HPBA), 5-aminoisophthalic acid (H2AIP) and N,N-dimethylacetamide (DMA)), was fabricated using a solvothermal method. JLNU-500 has 3D network architecture with 1D nanopore channels. The prepared JLNU-500 can activate peroxymonosulfate (PMS) for Rhodamine B (RhB) dye decolorization. Interestingly, catalyst JLNU-500 exhibited high efficiency for PMS activation, and nearly 100% (above 99.8%) removal of RhB with a high concentration (50.0 mg L−1, 100 mL) was achieved within 6 min. The reaction rate constant of the JLNU-500/PMS system was 1.02 min−1 calculated based on the pseudo-first-order kinetics, which is higher than that of the other reported catalysts. Furthermore, the factors, which could influence PMS activation were also investigated, such as PMS dosage, catalyst dosage, pollutant RhB concentration, reaction temperature and solution pH. More importantly, the radical trapping experiments ferreted out that sulfate (SO4˙−) and hydroxyl (˙OH) radicals were the dominating oxidants in the removal of RhB. Moreover, the possible degradation mechanism was elucidated. This study provides new prospects for fabricating new MOFs that can potentially be employed for high-efficiency catalytic oxidation as heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

Singlet oxygen (1O2), representing an important reactive oxygen species, has promising applications in biomedical, material, and environmental sciences. Photosensitized production of 1O2 using organic dyes is highly desirable and the exploration of highly efficient photosensitizers has received considerable attention. Herein, two tridentate Pt(II) complexes, i.e., cationic 1(PF6) and neutral 2, modified with the ethynylnaphthalimide chromophore, were designed and prepared for the application in 1O2 generation. Spectroscopic studies and computational results suggest that 1(PF6) and 2 display the lowest-energy absorption bands centered at 435–465 nm with the molar extinction coefficients of 0.6–3.2 × 104 M−1 cm−1, originating from the singlet ligand-to-ligand charge transfer (1LLCT) and a mixture of 1LLCT and singlet ligand-centered (LC) transitions, respectively. Moreover, they show similar phosphorescence at 620–640 nm assigned to the Pt-perturbed triplet LC emission of the ethynylnaphthalimide moiety. Thanks to the relatively long phosphorescence lifetimes, these complexes exhibit O2-dependent phosphorescence intensities with good reversibility and stability. They are able to behave as efficient triplet photosensitizers to promote the 1O2 generation with high quantum yields (84–89%). This work indicates that the combination of an organic chromophore with Pt(II) complexes provides an effective method to obtain photosensitizers for 1O2 generation. [ABSTRACT FROM AUTHOR]

The design of highly efficient organic/inorganic photocatalysts with visible-light response has attracted great attention for the removal of organic pollutants. In this work, the polyacrylonitrile (PAN) worked as the matrix polymer, while polyaniline (PANI) and Sb2S3–ZnO were used as organic/inorganic photocatalysts. The heterojunction PAN/PANI–Sb2S3–ZnO photocatalyst was prepared using electrospinning and surface ultrasound. PAN/PANI–Sb2S3–ZnO exhibited an excellent visible-light absorption intensity in the wavelength range of 400–700 nm. The maximum removal efficiencies of PAN/PANI–Sb2S3–ZnO for four organic dyes were all greater than 99%. The mechanism study showed that a dual Z-scheme could be constructed ingeniously because of the well-matched bandgaps between organic and inorganic components in the photocatalyst, which achieved efficient separation of photogenerated carriers and reserved photogenerated electrons (e−) and holes (h+) with strong redox ability. The active species •OH and •O2− played an important role in the photocatalytic process. The composite photocatalyst also had excellent stability and reusability. This work suggested a pathway for designing novel organic/inorganic composite photocatalysts with visible-light response. [ABSTRACT FROM AUTHOR]

The combination of semiconductors and transition metal compounds for Fenton‐like application has been widely reported. However, there are still some problems that can be further studied such as the optimization of metal species and in‐depth research of mechanism. In this paper, using melamine and copper acetate as raw materials, a kind of composite of copper oxide and graphitic carbon nitride (CuO/g‐C3N4) is synthesized by a facile hydrothermal method. The synthetic conditions such as type of transition metal salt and ratio of raw material are further optimized. With the presence of H2O2, the CuO/g‐C3N4 composite shows exceptional broad‐spectrum Fenton‐like catalytic performance against the organic dyes in aqueous solution within a wide pH range, and the highest degradation rate of organic dyes can reach 99% within 10 min. After eight times of recycling, the catalytic activity of the composite can still remain more than 85%. More importantly, the CuO/g‐C3N4 composite presented excellent anti‐interference ability toward heavy metal ions and complex pollutants. Finally, the enhanced Fenton‐like catalytic mechanism is illustrated in detail. [ABSTRACT FROM AUTHOR]

Disperse dyes are an important group of colorants for dyeing polyester fibers. Approximately 30.000 tons of disperse dyes are released into the waste water annually from spent dyebaths. Therefore, methods for decolorizing such dyes are of general interest. The reductive after-treatment of disperse dyes using reducing agents, such as Na2S2O4, is a widely used process to improve rub fastness through dye reduction. Electrochemical dye reduction could be an alternative process for reductive dye treatment. In this work C.I. Disperse Orange 62 was used as a representative dye to study the direct cathodic reduction of a disperse dye with cyclic voltammetry. As anticipated for dispersed organic matter, relatively low current densities were observed, which strongly depend on the state of dispersion of the dye. The current density was increased by using dispersions prepared through dye precipitation from DMF solution and by the use of N-cetyl-N,N,N,-trimethyl-ammonium bromide as a cationic surfactant. The results demonstrate the successful cathodic reduction of a dispersed organic dye; however, the low solubility of the reaction products in the aqueous electrolyte hinders an efficient cathodic dye reduction. [ABSTRACT FROM AUTHOR]

Inhomogeneity in single molecule electron transfer at the surface of lipid in a single vesicle has been explored by single molecule spectroscopic technique. In our study we took Di-methyl aniline (DMA), as the electron donor (D) and three different organic dyes as acceptor. These dyes are C153, C480 and C152 and they reside in different regions in the vesicle depending upon their preference of residence. For each probe, we found fluctuations in the single-molecule fluorescence decay, which are attributed to the variation in the reactivity of interfacial electron transfer. We found a non-exponential auto-correlation fluctuation of the intensity of the probe, which is ascribed to the kinetic disorder in the rate of electron transfer. We have also shown the power law distribution of the dark state (off time), which obeys the levy's statistics. We found a shift in lifetime distribution for the probe (C153) from 3.9 ns to 3.5 ns. This observed quenching is due to the dynamic electron transfer. We observed the kinetic disorderness in the electron transfer reaction for each dye. This source of fluctuation in electron transfer rate may be ascribed to the inherent fluctuation, occurring on the time scale of ~ 1.1 ms (for C153) of the vesicle, containing lipids. [ABSTRACT FROM AUTHOR]

In this work, nanocomposites based on titanium dioxide and reduced graphene oxide (TiO2@rGO) with different weight percentages of rGO (4, 8, and 16 wt%) were prepared by the hydrothermal/solvothermal synthesis method and thermally treated at 300 °C. The prepared nanocomposites were explored for the removal of methylene blue dye (MB) in the presence of simulated solar illumination as well as natural sunlight. The structural, morphological, chemical, and optical properties of the as-synthesized TiO2@rGO nanocomposites were characterized. The obtained results of the graphene-based nanocomposite materials indicated the existence of interactions between TiO2 and rGO, i.e., the Ti–O–C bond, which confirmed the successful integration of both components to form the TiO2@rGO nanocomposites. The addition of rGO increased the specific surface area, decreased the band gap energy, and increased the photocatalytic degradation efficiency of MB from water compared to TiO2 nanoparticles. The results of photocatalytic activity indicated that the amount of rGO in the prepared TiO2@rGO nanocomposites played a significant role in the application of different photocatalytic parameters, including the initial dye concentration, catalyst concentration, water environment, and illumination source. Our studies show that the reinforcement of the nanocomposite with 8 wt% of rGO allowed us to obtain the maximum photocatalytic decomposition performance of MB (10 mg·L−1) with a removal percentage of 99.20 after 2 h. Additionally, the obtained results show that the prepared TiO2@rGO_8 wt% nanocomposite can be used in three consecutive cycles while maintaining photocatalytic activity over 90%. [ABSTRACT FROM AUTHOR]

The development of fluorophores with photoemission beyond 1000 nm provides the opportunity to develop novel fluorescence microscopes sensitive to those wavelengths. Imaging at wavelengths beyond the visible spectrum enables imaging depths of hundreds of microns in intact tissue, making this attractive for volumetric imaging applications. Here, a novel shortwave‐infrared line‐scan confocal microscope is presented that is capable of deep imaging of biological specimens, as demonstrated by visualization of labeled glomeruli in a fixed uncleared kidney at depths beyond 400 µm. Imaging of brain vasculature labeled with the near‐infrared organic dye indocyanine green, the shortwave‐infrared organic dye Chrom7, and rare earth‐doped nanoparticles is also shown, thus encompassing the entire spectrum detectable by a typical shortwave‐infrared sensitive InGaAs detector. [ABSTRACT FROM AUTHOR]

As an effort to observe the impact of pollution on the aquatic environment, water quality monitoring calls for the development of early detection technologies that are fast, efficient, and inexpensive. Currently, electrochemical sensors are an alternative technology to sensitively analyze pollutants in the aquatic environment. Engineering working electrodes to sense polluting compounds is the target of technology development. This work studies material compositions consisting of graphite carbon with TiO2 nanoparticles as a photoelectrode to analyze chemical oxygen demand (COD) in methylene blue (MB) organic dye wastewater. The materials were prepared by physically mixing the two components and one-pot chemical synthesis, characterizing their microstructure and crystallinity. Then, their analytical performance was assessed by measuring MB dye as a sample against the mass variation of 1:1 (w/w) and 1:2 (w/w) photoelectrodes. The results showed similar 1:1 (w/w) performance with the relevant and theoretical COD. The straightforward synthesis and eco-friendly materials are key factors in the fabrication of COD sensor. This study proposes a technical process for the fabrication and application of photoelectrodes in detecting the chemical oxygen demand (COD) of methylene blue dye. It solves the problems of COD detection in identifying water quality in wastewater, and the problems of long and the problems of dangerous materials used against COD determination. It provides a new understanding of rapid COD detection to measure water quality in wastewater. In practical applications, the fabricated photoelectrode was placed into dye solution and connected to a potentiostat instrument, which was irradiated by ultraviolet (UV) light to initiate the photoelectrocatalytic reaction. The accumulation of organic dye in water will generate the electrical properties (photocurrent) of the photoelectrode, which can the be measured by a multipulse amperometry system. It performs two performance functions at once, namely photoelectrodegradation and COD sensing. In COD sensor performance, the photocurrent response is plotted against the time duration where the photocurrent generated is proportional to the oxidation performance against the organic dye concentration and calculated by the Faraday equation. This research offers several advantages, such as fast response time and real-time detection for COD determination. It also provides more sensitive and accurate measurement of organic pollutants in water. The COD photoelectrocatalysis method can be a practical application for rapid detection of methylene blue organic dye. [ABSTRACT FROM AUTHOR]

Numerous catalysts for water pollutant mitigation have been developed over recent decades. However, the utilization of catalysts embedded in 3D structures remains challenging. This study aims at fabricating 3D-printed TiO2/SiO2/polymer scaffolds for the degradation of organic dyes, specifically Methylene Blue (MB) and rhodamine B (Rh B). The TiO2/SiO2/polymer scaffolds were fabricated by stereolithography (SLA) technique, using TiO2 photocatalyst synthesized via a solution combustion process, silica adsorbent prepared from sugarcane leaves, and photocurable resin as feedstock. X-ray diffraction analysis confirmed that TiO2 exhibited anatase/rutile/brookite triphasic structure while SiO2 possessed amorphous structure. Scanning electron micrographs revealed that TiO2 and SiO2 particles uniformly deposited on the surface of the photocurable resin. The adsorption activity of the TiO2/SiO2/polymer scaffolds was examined in the dark for 24 h to ensure that adsorption equilibrium was achieved. Photocatalytic examinations were conducted under UV light (λ = 365 nm). The TiO2/SiO2/polymer scaffolds efficiently demonstrated their potential dye removal efficiency against MB and Rh B dyes as 81.9% and 60%, respectively. Reusability testing revealed that after hydrogen peroxide treatment, the used scaffolds exhibited the degradation ability in a comparable range to the as-fabricated scaffolds. An application of a 3D printing technique for water pollution reduction was successfully demonstrated in this study. [ABSTRACT FROM AUTHOR]

Herein we report that a surfactant modified quantum dot-complex (S-QDC; with λem-515 nm) nanocomposite, as a donor fluorophore, exhibits enhanced Förster resonance energy transfer (FRET) efficiency to an acceptor organic dye (λem-576 nm) in comparison to only the QDC. The proposed S-QDC (consisting of a ZnS quantum dot, zinc quinolate inorganic complex and cetyltrimethylammonium bromide (CTAB) surfactant) provides the unique and selective ratiometric visual detection of organic dyes present as food colorants in commercial chili powder, tomato ketchup and mixed fruit jam. Notably, the S-QDC shows a limit of detection (LOD) as low as 2.2 nM in the linear range of 0.17–4.89 μM for food colorants. Furthermore, the present work will bring new possibilities to unravelling the chemistry among surfactants, inorganic complexes and quantum dots to make newer optical materials with futuristic scope of utilization ranging from optical sensors to light emitting devices. [ABSTRACT FROM AUTHOR]

Layer-by-layer assembly of strong polyelectrolytes was successfully implemented on hydrophobic particles in degassed saline water thanks to de-gassing-reduced hydrophobic interactions and salinity-reduced hydration. The resulting polyelectrolyte multilayer coated particles were readily converted to hydrophobic yolk/hydrophilic shell particles for the removal of organic dyes from water via both electrostatic and hydrophobic interactions. [ABSTRACT FROM AUTHOR]

There has been a notable surge of interest in the field of dye sensitized solar cells (DSSCs) in recent years due to their remarkable performance in indoor/ambient and diffused light conditions. A significant portion of these highly efficient indoor DSSCs employs organic dyes based on triphenylamine. In this study, we present the findings of our investigation on two metal‐free D‐π‐A organic dyes, namely triphenylamine (YK 10) and hexyloxy‐substituted triphenylamine (YK 11), serving as electron donors. These dyes feature a 3,3′′‐dioctyl‐2,2′:5′,2′′‐terthiophene π‐spacer and cyanoacetic acid as the anchoring group. In order to comprehensively assess the relationship between the molecular structure, physical properties, and solar cell performance, we conducted in‐depth analysis involving photophysical, electrochemical, and theoretical studies. Our results indicate that these dyes possess the ability to effectively capture light within the visible spectrum and exhibit suitable energetic characteristics for efficient electron injection and dye regeneration. Through the utilization of density functional theory (DFT) modeling, we explored the interfacial adsorption configuration of the dyes on the TiO2 semiconductor, revealing the involvement of the cyano group in the anchoring mechanism for both sensitizers. Moreover, the intramolecular S...CN interaction in these dyes was verified through topological quantum‐theory‐of‐atom‐in‐molecule (QTAIM) analysis, which facilitates additional intramolecular charge transfer pathways. The DSSCs incorporating YK 10 and YK 11 demonstrated power conversion efficiencies (PCEs) of 6.42 % and 6.22 %, respectively, under full sun illumination (100 mW/cm2). Remarkably, under both standard 1000 lux CFL and LED illumination conditions, YK 11 exhibited superior performance with PCEs of 8.29 % and 5.89 %, respectively, surpassing the efficiencies of YK 10, which achieved 7.50 % and 5.09 % efficiencies under the same conditions. [ABSTRACT FROM AUTHOR]

Decorating the living space, objects, body and clothes with colour is a widespread human practice. While the habitual use of red mineral pigments (such as iron-oxide, e.g., ochre) by anatomically modern humans started in Africa about 140,000 years ago, the earliest documentation of the use of organic plant or animal-based red pigments is known from only 6,000 years ago. Here, we report the oldest reliable evidence of organic red pigment use 15,000 years ago by the first sedentary hunter-gatherers in the Levant. SEM-EDS and Raman Spectroscopy analyses of 10 red-stained shell beads enabled us to detect and describe the use of a colourant made of Rubiaceae plants roots (Rubia spp., Asperula spp., Gallium spp.) to colour personal adornments from the Early Natufian of Kebara cave, Mount Carmel, Israel. This adds a previously unknown behavioural aspect of Natufian societies, namely a well-established tradition of non-dietary plant processing at the beginning of the sedentary lifestyle. Through a combined multidisciplinary approach, our study broadens the perspectives on the ornamental practices and the chaînes opératoires of pigmenting materials during a crucial period in human history. [ABSTRACT FROM AUTHOR]

A novel, magnetic HKUST-1 MOF based on MgFe2O4-NH2 was designed and synthesized in two steps and applied effective removal of malachite green (MG), crystal violet (CV), and methylene blue (MB) from water samples. Characterization of the newly synthesized MgFe2O4-NH2-HKUST-1 was performed by various techniques such as Fourier transform infrared spectroscopy, X-ray diffraction, Field emission scanning electron microscopy, Brunauer–Emmett–Teller, Thermal gravimetric analysis, and Vibration sampling magnetometry. Malachite green, crystal violet and methylene blue are toxic and mutagenic dyes that can be released into the water in different ways and cause many problems for human health and the environment. The removal of malachite green, crystal violet, and methylene blue from aqueous solutions was investigated using the magnetic HKUST-1 in this research. The effect of various parameters such as pH, amount of sorbent, dye concentration, temperature, and contact time on dye removal has been studied. The results showed that more than 75% of dyes were removed within 5 min. Adsorption isotherms, Kinetic, and thermodynamic studies were investigated. The results of this study show that adsorption capacity of the magnetic adsorbent is equal to 108.69 mg g−1 for MG, 70.42 mg g−1 for CV, and 156.25 mg g−1 for MB. This study shows the good strategy for the synthesis of the functionalized magnetic form of HKUST-1 and its capability for increasing the efficiency of the removal process of malachite green, crystal violet, and methylene blue from an aqueous solution. [ABSTRACT FROM AUTHOR]

Hydrothermal synthesis was used to create four different POM-based compounds, namely {[Co(Hptpm)2(β-Mo8O26)0.5(ξ-Mo8O26)0.5]}·H2O (1), [Co(Hptpm)2(δ-Mo8O26)]·H2O (2), [Co(Hptpm)2(β-Mo8O26)] (3) and [Zn(Hptpm)2(β-Mo8O26)] (4) (ptpm = 4-[3-(3-pyridine-2-yl-[1,2,4]triazol-4-yl)-propyl]- morpholine). 1-4 containing different octamolybdate isomers were characterized. Compounds 1-4 showed good electrochemical performance and can be utilized as bifunctional sensors for NO2 -, H2O2, Cr(VI) and Fe(III). Taking compound 1 as an example, the detection limits are 0.081 μM for NO2 -, 0.072 μM for H2O2, 0.054 μM for Cr(VI) and 0.063 μM for Fe(III), respectively. Compounds 1-4 have good capacitance. Moreover, compounds 1-4 also show good adsorption properties for organic cationic dyes. The cationic dyes include methylene blue (MB), crystal violet (CV) and neutral red (NR). In addition, 1-4 have excellent characteristics that can reduce Cr(VI) to Cr(III) by photocatalytic technology. Within 30 min, the reduction rates were 95.85% for 1, 93.99% for 2, 90.29% for 3 and 88.18% for 4. [ABSTRACT FROM AUTHOR]

Most conventional dye treatment methods have limited efficacy as they are expensive, time-intensive and result in incomplete dye removal from water. Addressing these issues, this work reports the fabrication of a NaTiO3/g-C3N4 heterojunction photocatalyst, which was utilized for the advanced oxidation process under sunlight irradiation to remove crystal violet (CV) and methylene blue (MB) dyes and their binary mixture. The perovskite NaTiO3 is synthesized via a simple hydrothermal method and combined with graphitic carbon nitride, formed through the thermal decomposition of melamine, to fabricate the heterojunction. The scanning electron microscopy (SEM) images reveal that spherical NaTiO3 nanoparticles are aggregated on the sheet-like surface of g-C3N4 and structural analysis utilizing the XRD pattern confirms the formation of a heterojunction. From the Tauc plot the bandgap of the material is estimated to be 2.3 eV. The complete degradation of MB was observed within 25 min, while CV and the binary mixture require 20 min for complete degradation. The high visible light absorption of NaTiO3 and large surface area of g-C3N4 were attributed to the enhanced catalytic performance of the heterojunction. Additionally, scavenger studies indicated that the radical species h+ and +OH played a crucial role in the photocatalytic degradation of the dyes. Reusability studies confirm good stability up to five cycles of dye degradation. The results establish the NaTiO3/g-C3N4 heterojunction as an efficient photocatalyst to remove organic dyes from water, thus having immense potential in water purification. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Isoindigo (IID) is widely used as organic dye and conjugated unit in opto‐electronic materials. Functionalization of IID to increase its structural complexity is demanding for obtaining diversity properties. Herein, we developed a direct C—H/N—H activation method of IIDs via double alkyne annulations and synthesized π‐extended IIDs with two pairs of 5/7 membered rings. The structure of the π‐extended IIDs was characterized and confirmed by 1H NMR, 13C NMR, HRMS and X ray crystal analysis. Their physical properties were characterized by UV‐vis absorption, cyclic voltammetry and thermogravimetric analysis. The absorption coefficient of the annulated products enhanced significantly compared with the non‐annulated analogue. [ABSTRACT FROM AUTHOR]

As a novel form of carboxylate comb‐like copolymers, SAM‐(m)PEG was prepared by polymerizing styrene (S), acrylic (A), and maleic anhydride (M) to obtain a random copolymer labeled SAM. SAM was then esterified using either polyethylene glycol (PEG) or methyl PEG (mPEG), a waterborne polymer dispersant for dispersing and stabilizing C.I. Pigment Yellow 180 (PY 180). The structures of SAM‐(m)PEG and the ground suspension of PY 180 were characterized by Fourier transform infrared (FT‐IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, scanning electron microscopy (SEM), a nanoparticle size analysis, and viscometry. The effects of different branch chains, synthetic formulas, and grinding conditions on the dispersibility of SAM‐(m)PEG were evaluated. In addition, the optical properties of the pigments were investigated after ultrafine grinding. The adsorption mechanism between the SAM‐(m)PEG dispersants and PY 180 particles is also discussed. SAM‐PEG6002 outperformed the other SAM‐(m)PEG dispersants owing to its excellent dispersion and stability. When used as the dispersant, the average particle size (Z‐average) of PY 180 after grinding was 264.6 nm, and the particle size distribution became narrow (PDI=0.089). Moreover, SAM‐PEG6002 effectively maintained the color performance of the pigment, and the product was successfully applied to the pigment coating. Therefore, SAM‐PEG6002 is an effective waterborne polymer dispersant for organic pigments. [ABSTRACT FROM AUTHOR]

Some organic dyes and photosensitizers with strong visible absorption can behave as photo‐responsive oxidase mimics. However, the relationship between the photo‐oxidase activity and molecular structure remains unclear to date. In this work, a new type of photosensitizer with the characteristics of molecular rotors, namely DPPy, served as the molecular scaffold for further investigation. To adjust the photocatalytic oxidation ability, DAPy and CBPy were designed and synthesized based on the enhancement and diminishment of the intramolecular charge transfer (ICT) process, respectively. Kinetic studies revealed that DAPy and CBPy both exhibited highly efficient photo‐activated oxidase‐like activity with 3,3′,5,5′‐tetramethylbenzidine (TMB) as the substrate, which were in good accordance with their molecular engineering to promote either type I or type II reactive oxygen species (ROS) generation. Impressively a colorimetric method based on the visible light induced oxidase‐like activity of molecular rotors was developed to determine the environmental temperature for the first time. Both DAPy and CBPy showed distinct sensitivities toward temperature as compared with several molecular rotors based on the typical fluorimetric detection. This work provides a new strategy for the application of molecular rotors to overcome the non‐emissive challenge in temperature sensing. [ABSTRACT FROM AUTHOR]

In this work, cobalt activated TiO2 photocatalyst have been successfully prepared on graphene oxide (GO) using simple and cost‐effective method to prepare Co‐TiO2/GO nanocomposites for the photocatalytic treatment of methylene blue (MB), representative organic dye, under visible light irradiation. The as‐prepared samples were characterized by X‐ray diffraction (XRD), High resolution transmission electron microscope (HRTEM), X‐ray photoelectron spectroscopy (XPS), UV‐vis diffused reflectance spectra (DRS), Raman spectroscopy and photoluminescence spectroscopy (PL). The characterization results confirmed that Co‐TiO2 catalyst is decorated on the graphene oxide. The photocatalytic efficiency of Co‐TiO2/GO for the degradation of MB was also improved by changing the proportion between Co‐TiO2 and GO. Highest photocatalytic activity was observed for Co‐TiO2 loaded with 5 wt % GO (88.7 %) compared with neat Co‐TiO2 (43.4 %) after 180 min of visible light irradiation. Furthermore, degradation by products was analyzed on Quadrupole Time‐of‐Flight Liquid Chromatography/Mass Spectroscopy (QTOF/LCMS) and the possible degradation pathway was proposed. It is investigated that the Co‐TiO2/GO nanocomposite has potential use in the catalytic degradation of organic contaminants under visible light irradiation. [ABSTRACT FROM AUTHOR]

Anisotropic properties of aspherical nanoparticles make it possible to significantly expand their spectral-optical applications associated with local field effects. The plasmon resonance characteristics of such particles have additional features that conductive nanoglobules do not possess. The results of synthesis and morphological analysis of ellipsoidal hematite nanoparticles coated with a gold shell and spherical magnetite nanoparticles by atomic force microscopy are presented. The absorption spectra of aqueous solutions of such nanoparticles, as well as conductive nanoparticles with chain molecules adsorbed on them, are obtained. Based on the methods of dynamic light scattering, histograms of particle size distribution are constructed. The influence of spheroidal magnetic nanoparticles coated with a gold shell on the luminescence intensity of molecules of an organic dye (fluorescein) and poly[2-methoxy-5(2'-ethylhexyloxy)-1,4-phenylenevinylene] is studied. An increase in the luminescence intensity of both types of luminophors at certain concentrations of metallized spheroidal nanoparticles is detected. A mathematical model of radiative and nonradiative processes in the studied colloidal system is presented, as well as the results of calculations of spectral and velocity characteristics based on well-known applied FDTD packages. Characteristic graphs are constructed for the spectral density of the number of photons emitted at a certain frequency of the combined system "molecule–nanoparticle" for various positions of the nanoparticle relative to the molecule and two characteristic directions of the transition dipole moment vector. The relationship between the frequencies of two plasmon resonances and the eccentricity of the spheroid revealed in the model is clearly manifested in the obtained spectral curves. The closer the spheroid eccentricity to 0, the smaller the frequency interval between two spaced plasmon resonance peaks, which merge into a single spectral band at zero eccentricity. The results obtained can be used in the development and modification of sensors with an adjustable conformational structure of macrochains, such as luminescent optical testers for the concentration of molecular oxygen (including singlet oxygen) and chemical sensors based on the effects of surface plasmon resonance and surface-enhanced Raman scattering. [ABSTRACT FROM AUTHOR]

To reveal the structure of tunnel-luminescence centres in AgBr(I) emulsion microcrystals (EMCs), we perform spectro-sensitometric and kinetic studies of their low-temperature (T = 77 K) luminescence. The luminescence characteristics depending on the binder, the presence and the nature of sensitizing additions (dyes) and the oxygen treatment are studied quantitatively. Special attention is paid to the comparative studies of the Stokes and dye-induced anti-Stokes luminescence components in the AgBr(I) EMCs. When the dye-sensitized AgBr(I) EMCs distributed in the polyvinyl alcohol are excited by the light photons with the energies corresponding to the intrinsic absorption region of the EMCs (λmax ≈ 460 nm), the kinetics of the luminescence band centred at the wavelength λmax ≈ 560 nm is monotonic. On the contrary, upon excitation by the photons corresponding to the absorption region of a J-aggregated dye (λmax ≈ 680 nm), the kinetics of the anti-Stokes glow (λmax ≈ 560 nm) is characterized by a rapid 'flash' followed by a gradual decrease to a stationary level (a 'flash enhancement'). These results indicate that a non-equilibrium transfer of charge carriers from the dye, which is adsorbed on the EMC surface, to the EMC volume depends essentially on the binder. If gelatine is the binder, this process is significantly affected by the oxygen adsorption, whereas the resulting effect depends on the aggregate form of the adsorbed dye. Understanding of physicochemical processes that govern the luminescence centres should enable one to control the structural transformations of the donor-acceptor complexes and clusters, which are responsible for the unique photometric properties of AgBr(I), and optimize their parameters for various applications in optoelectronics, holography, photographic materials science, optical sensors and solar energy systems. [ABSTRACT FROM AUTHOR]