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Ce2(MoO4)3 was prepared using dielectric barrier discharge (DBD) plasma method, co-precipitation method and hydrothermal method, respectively, with water/ethanol (W/O) as solvent, oleylamine (OAm) and oleic acid (OAc) as additives. Preparation method showed significant influence on the morphological and structural properties, as well as photocatalytic performance. Ce2(MoO4)3 synthesized with DBD plasma (MO-P) was mainly flowerlike nanosheets, which were beneficial to promoting electron transfer and providing more space for catalytic activity. Also, MO-P samples exhibited more oxygen vacancies, which were conducive to the photocatalytic performance. What's more, MO-P showed lower PL intensity and narrow energy gap, which implied a slow photoelectron–hole pair recombination rate and an increased electron transfer rate. The degradation rate of methyl orange (50 mg/L) could achieve 98% within 12 min with 0.5 g/L MO-P. Hydroxyl radicals (·OH) and superoxide radicals (·O2−) played a major effect. Plasma synthesis method exhibited potential application prospect in photocatalysts preparation. [ABSTRACT FROM AUTHOR]

A Ca–Al layered double hydroxide (LDH)-based highly efficient adsorbent is synthesized and applied for aqueous-phase removal of toxic organic dye—malachite green. Separate nucleation and aging step (SNAS) method is applied for the adsorbent synthesis. Effect of variation in Ca/Al ratio and calcination temperature on the adsorption efficiency has been investigated. The synthesized adsorbent with its favorable morphology and microstructure exhibits excellent adsorption performance. Structural characteristics of different intermediate adsorbents are studied with PXRD, FTIR, TGA and FESEM which rationalize the structural features governing the observed adsorption efficiency. In this study, initial dye concentration is varied from 200 to 800 ppm. The synthetic conditions lead to the development of a highly active adsorbent surface. The adsorption capacity is found to be as high as 3042 mg g−1 with an optimized dosage of 300 mg L−1 for a particular adsorbent. Standard adsorption models are employed to investigate the adsorption mechanism, and the Langmuir–Freundlich model is found to best fit the experimental results. A detailed study on adsorption equilibrium and thermodynamics has also been carried out to understand the adsorption process that might be useful for practical application. [ABSTRACT FROM AUTHOR]

Abstract—First data are reported on the content of plant pigments in bottom sediments of different types in the large shallow Vozhe and Lacha lakes in northwestern Russia. The distribution patterns of chlorophyll a with pheopigments and organic matter in the surface sediments are consistent with sedimentation features. Among the depositional processes, bed erosion, transport of suspended matter, and redeposition dominate in Lake Vozhe, while sedimentation prevails in Lake Lacha. Lake Vozhe is dominated by coarse-grained sediments and shows more pronounced mosaic structure of the sediment complex than Lake Lacha. The lakes show similar values of production indicators for the same type of sediments. Spatial distribution of chlorophyll a and the products of its degradation in the benthal of Lake Vozhe is more heterogeneous than in Lake Lacha. The relative content of the products of chlorophyll degradation in bottom sediments of the studied lakes is about 60%. Average concentration of organic matter calculated considering the areas of bottom sediments of different types in sediments of Lake Vozhe (11.8 ± 2.7%) is 2.3 times less than that of Lake Lacha (27.4 ± 5.5%). The average values of the total content of chlorophyll a and pheopigments characterize Lake Vozhe as a typical mesotrophic water body (38.3 ± 9.3 μg/g dry sediment), and Lake Lacha as an eutrophic basin at the initial stage (72.2 ± 17.7 μg/g dry sediment). The plant carbon calculated from the content of sedimentary pigments amounts an insignificant part of the total primary production of phytoplankton, periphyton, and macrophytes (0.38% in Lake Vozhe and 0.46% in Lake Lacha) and corresponds to 5.3–6.5% of the total organic carbon in bottom sediments. In the absence of anthropogenic pollution, the lakes show signs of eutrophication due to the transboundary transfer and nutrient inflow from the watershed under warming conditions. [ABSTRACT FROM AUTHOR]

The discoveries recommend that the photoinduced conditions of fluorescein-determined go about as impetus for photochemically combining polysubstituted quinolines in ethanol at room temperature under air environment by means of revolutionary Friedländer hetero-annulation of 2-aminoaryl ketone and α-methylene carbonyl compound. This study lays out an original capability for photochemically orchestrating fluorescein. This non-metallic organic dye is economically accessible and modest, producing great outcomes, accelerating the cycle, and achieving a high compound economy. The turnover number (TON) and turnover recurrence (TOF) of polysubstituted quinolines have been determined. This cycle will likewise run on a gram scale, demonstrating the chance of modern applications. [ABSTRACT FROM AUTHOR]

Novel organic dyes were designed (MAX114-1–MAX114-7) by adding different π-spacer groups to the reference dye (MAX114) for high efficiency of dye-sensitized solar cells (DSSCs). Their geometries, electronic structures and optical properties and photovoltaic performance were theoretically investigated by density functional theory (DFT) and time-dependent DFT (TD-DFT) methods. Photovoltaic parameters influencing power conversion efficiency (PCE) were calculated and discussed for DSSC applications, such as light-harvesting efficiency (LHE), electron injection driving force (∆Ginj), dye regeneration driving force (∆Greg), nonlinear optical properties (NLO) and reorganization energy. The optimized geometries of designed dyes have more coplanarity than the MAX114, which is beneficial for efficient intramolecular charge transfer and the suppression of dye aggregation. The energy gaps of the designed dyes have significantly decreased compared to MAX114, leading to red-shifted absorption spectra and improved light-harvesting ability. It was found that the studied dyes have good electron injection and dye regeneration performance due to a more negative value of ∆Ginj and a lower value of ∆Greg. The results show that the designed dyes have a higher μnormal, higher LHE, higher NLO properties, lower ∆Greg, reasonable ∆Ginj, and a better balance of λh and λe, resulting in a higher VOC and JSC than MAX114. This indicates that the designed dyes (MAX114-1–MAX114-7) could be used as sensitizers to improve the effectiveness of DSSC devices. [ABSTRACT FROM AUTHOR]

The objective of this study was to eliminate organic pollutants from the fluid stage employing silver nanocatalyst relationship with NaBH4 using Morinda citrifolia leaf extract. Silver nanoparticles were effectively evolved utilizing the pyto-reduction method. The inferred nanocatalyst was preliminary confirmed by UV–Visible, FT IR, EDX, SEM/TEM-HR TEM, and DLS spectroscopic investigations. The size and morphology of the silver nanoparticles were ascertained to be 28 nm with spherical shape morphological characteristics through SEM/TEM microscopic examination. As a potential outcome, silver catalyst has such an elevated catalytic performance, when it comes to decomposing organic dyes include alizarin red, pararosaniline, eosin blue, methyl violet, and Congo red. Among the organic pollutants eliminated employing by silver nanocatalyst, the degradation of Congo red was found to be the most efficacious 100% in about 5 min respectively. [ABSTRACT FROM AUTHOR]

Photocatalytic degradation of organic dyes in less-toxic products under visible light irradiation is considered a green method which is widely used in this field. In this manuscript, a novel coordination polymer (PUCP1) based hybrid-nanocomposite (PUCP1@rGO) was synthesized. The PUCP1 and nanocomposite were successfully characterized by using various analytical techniques such as SCXRD, FT–IR, PXRD, TGA, FE–SEM, BET and XPS. The PUCP1 exhibits a 2D framework with an uninodal 4-connected net and sql topology. The PUCP1@rGO was applied as a sensitive and selective photocatalyst for significant degradation of Safranin-O (SO) dye. The rGO played an important role in the expansion of photocatalytic activity of the PUCP1 by inhibiting the recombination probability of electron–hole pairs. The results revealed that PUCP1@rGO nanocomposite can degrade 76% of SO dye in only 90 min under visible light at a neutral pH. The PUCP1@rGO was found very sensitive to photocatalytic degradation of SO dye because a very small amount of catalyst (i.e. 10 mg) degrades the 5 μM concentration of SO dye in the presence of light. The PUCP1@rGO is a reusable photocatalyst for up to 5 cycles. Rarely, any sensitive photocatalyst for SO dye is reported in literature than PUCP1@rGO which degrades SO dye in a very small period with significant quantity. Thus, PUCP1@rGO can be used as a promising photocatalyst for the degradation of SO dye. In this work, we have synthesized a novel coordination polymer (PUCP1) and nanocomposite (PUCP1@rGO) by impreganation of rGO in PUCP1 framework.The PUCP1 exhibited selective photocatalytic response towards safranin-O dye under visible light irradiation and impregnation of rGO enhance the photocatalytic properties of PUCP1@rGO nanocomposite as compared to parent PUCP1.The PUCP1@rGO nanocomposite degrade the safranin-O dye up to 76% in 90 min only under visible light. [ABSTRACT FROM AUTHOR]

The importance of pollutant remediation using solar energy is increasingly acknowledged as a viable method to solve the current environmental problems. To date, three-dimensional (3D) graphene architectures have demonstrated excellent photocatalytic performance due to their salient characteristics. The hydrothermal treatment is the commonly reported synthetic protocol in preparing various novel hybrid 3D graphene architectures. This chapter focuses on the recent progress in developing and applying hybrid 3D graphene for the photocatalytic remediation of organic pollutants such as dye molecules, emerging contaminants, and heavy metals. Various novel design based on semiconductor/3D graphene has led to the creation of highly efficient heterojunction photocatalyst. The transformation to a 3D architecture does not only improve the accessible surface area but also enhanced light harvesting capability and charge transport. In addition, we have also made an effort to discuss some photocatalytic antibacterial disinfection innovations. Finally, prospects in the construction of hybrid 3D graphene possessing enhanced photocatalytic materials are presented. [ABSTRACT FROM AUTHOR]

Water bodies are being poisoned by a variety of organic and inorganic pollutants in the modern era of industrial civilization. To solve this vital issue, various scientists and researchers have come up with an eco-friendly method of photocatalysis which is a promising strategy for the removal of organic pollutants especially organic dyes from wastewater. In the present work, we report the enhanced photocatalytic activity of graphene oxide (GO) nanosheets synthesized via a simple, cost-effective, and eco-friendly method. The photocatalytic ability to degrade Malachite green (MG) and Congo red (CR) was investigated as such dyes are primary chemical pollutants in the textile industry. To optimize the conditions for the best performance, experimental variables such as contact time, dye solution concentration, catalyst dose, and pH were adjusted. The present investigation reveals that GO synthesized by the novel route is an extremely efficient photocatalyst for the degradation of MG and CR and observed 100% degradation of MG in 60 min and 85% degradation of CR in 90 min under UV irradiation. The present investigation explores the potential of graphene oxide-based composite materials for future energy and environmental remediation. [ABSTRACT FROM AUTHOR]

Starting with Coumarin-6 dye, two novel D-π-A organic dyes C6X and C6N have been designed by attaching carboxylic acid and cyanoacrylic acid groups as anchoring groups to Coumarn-6 dye, respectively, to understand their potential use in dye-sensitized solar cells (DSSCs). The electronic structure and photophysical and photovoltaic properties of the novel designed dyes were studied using density functional theory DFT and time-dependent density functional theory TD-DFT with the Becke3-Parameter-Lee–Yang–Parr (B3LYP) functional and the 6-31G (d, p) basis set. Optimized structure and electronic properties (highest occupied molecular orbital energy (EHOMO), lowest unoccupied molecular orbital (ELUMO), and energy difference (Eg) between HOMO and LUMO) were calculated showing that C6N has the smallest band gap with the larger absorption region. Density of states (DOS), molecular electrostatic potential (MEP), natural bond orbital (NBO) analysis, non-linear optical (NLO) properties, UV–vis spectra, as well as some crucial parameters affecting the photovoltaic performance of DSSCs, such as light-harvesting efficiency (LHE), electron injection driving force (ΔGinject), dye regeneration driving force(ΔGreg), and the excited state life time(τe), were calculated to study the effect of the anchoring group on the DSSC performance. Additionally, the adsorption of C6X and C6N dyes on the TiO2 anatase (101) surface and the mechanism of electron injection were also investigated using a dye–(TiO2)9 cluster model using TD-B3LYP calculation. The calculated adsorption energies of the dyes suggest a strong adsorption of dyes to a TiO2 surface. The results show that C6N may be theoretically a good candidate as sensitizer of DSSC application. [ABSTRACT FROM AUTHOR]

Zinc zirconia nanocomposite was synthesized by chemical co-precipitation route using zinc chloride (ZnCl2), zirconium oxychloride octahydrate (ZrOCl2·8H2O), sodium hydroxide (NaOH) and ethylene diaminetetra acetic acid (EDTA). XRD, UV, SEM and EDX measurements were employed to characterize the as-prepared nanoparticles of zinc oxide (ZnO NPs), zirconia (ZrO2 NPs) and the zinc zirconia nanocomposite (ZZNC). Photocatalytic degradation of methylene blue (MB) dye in polluted water was investigated under visible light using ZZNC as the photocatalyst. UV/Vis spectrum confirmed an enhancement in the photocatalytic activity of ZZNC in MB dye-contaminated water. It was observed that more than 80% of the dye was degraded from polluted water while using ZZNC as a photocatalyst in 2.5 h. [ABSTRACT FROM AUTHOR]

Nowadays, aquatic pollution is one of the most important global challenges, due to discharges a wide variety of various hazardous materials from different activities which have significant environmental, economic and healthy impacts. Industries and activities related to organic dyes onsume large amounts of water and contribute significantly to the growing problem of water pollution. The current study describes the conversion of plant wastes into activated carbon sphere incorporated sulfonated polystyrene (AC/SPS) for adsorptive removal of Rhodamine B (RhB) and Congo Red (CR) dyes in a batch process. The prepared materials were characterized by different techniques such as XRD, FTIR, FESEM, TEM, BET-BJH, and TGA. The AC/SPS in weight ratio of 10% was used as a novel adsorbent for RhB and CR remediation. Batch adsorption experiment have been studied by investigating the effect of contact time, adsorbent dose, initial pH, and temperature. The maximum removal efficiency of RhB and CR onto AC/SPS under optimized conditions was estimated to be 34% and 98%, respectively. In addition, it has been found that Freundlich model provided the most appropriate fit for the adsorption of both RhB and CR dyes. Based on the thermodynamic study, it was proven that the adsorption process for both dyes is endothermic and spontaneous. The change in entropy was estimated to be 190.59 and 65.40 J/mol K for CR and RhB dyes, respectively. The kinetic study revealed that the adsorption of CR and RhB dyes followed the pseudo-second order and pseudo-first order kinetic models, respectively. [ABSTRACT FROM AUTHOR]

Organic dyes, porphyrins and inorganic complexes containing imidazole (IM) motifs have been demonstrated as a new class of sensitizers in dye-sensitized solar cells (DSSCs). Particularly, the amphoteric nature of IM-based motifs allows them to be used as donors (D), auxiliary donors (DA), linker/branch (π), or acceptors (A) in D–π–A-based organic dyes and porphyrins and also employed as cyclometalated heteroleptic and ancillary ligands in the Ru(II) and Ir(III) complexes for DSSCs. It is noteworthy that the introduction of IM chromophores in the dyes of D–π–A configuration can improve the light-harvesting properties and prohibit the charge recombination reactions due to the extension of the π-conjugated structures and hydrophobic nature. Similarly, in the case of inorganic complexes, the presence of IM motifs as ligands can improve the light-harvesting ability, give facilely tuned HOMO and LUMO energy levels, increase the charge recombination resistance and photostability. This results in enhanced photocurrent (JSC) and photovoltage (VOC) and consequently solar-to-power conversion efficiency (η) of DSSC devices based on Ru(II) and Ir(III) complexes. Considering the interesting DSSC applications of IM-derived molecules, in this review, we therefore comprehensively discuss their photophysical, electrochemical and photovoltaic properties reported so far and establish their structure–activity relationship to further advance the η of DSSCs. To the best of our knowledge, there is no such a review interpreting the importance of molecules possessing IM-motifs for DSSC applications to date. [ABSTRACT FROM AUTHOR]

Stimulus-responsive nanoparticles are among the most utilized nanoscale materials in biomedical applications. As these nanoparticles exhibit a manipulable response to a particular stimulus, such as pH, heat, and organic solvent, they are potential signalling units in diagnostic assays. This study aims to enhance the limit of detection and reduce the turnaround time of magnetic nanoparticle polymerase chain reaction (PCR) enzyme-linked gene assay (MELGA), an advanced PCR-based technique termed the solvent-sensitive nanoparticle (SSNP)-enhanced PCR assay. This technique was proposed to detect pathogenic enterotoxigenic Escherichia coli (ETEC) through applying stimulus-responsive nanoparticles. The SSNPs were elaborated with three main components, including mesoporous silica nanoparticles as a structural unit, organic dye (Nile red) as a payload, and the corresponding organic solvent-sensitive polymer shell as "gatekeeper" (poly(maleic anhydride-alt-methyl vinyl ether, PMAMVE). A suitable organic solvent capable of inducing polymer swelling and dye dissolution was investigated by considering a solubility parameter. Using ethanol, the encapsulated Nile red can diffuse out of the SSNPs faster than other solvents and reach a constant concentration within 15 min. For the PCR inhibition study, various SSNPs concentrations (10–30 μg/reaction) were mixed with the ETEC gene and PCR reagent. The results showed that the particles in this concentration range did not inhibit PCR. By comparing the efficacy of conventional PCR, MELGA, and SSNP-enhanced PCR assay, the proposed technique showed a better detection limit than that of PCR, whereas that of MELGA was the lowest. Moreover, compared to MELGA or conventional PCR, this technique provided remarkably faster results in the postamplification process. [ABSTRACT FROM AUTHOR]

Chinese Edison pearls, invented and produced in China by the Zhejiang Grace Pearl Jewelry Co., Ltd, are usually large and round with variable but attractive colors. Edison pearls have entered the jewelry market in 2011. However, the fine microstructural characteristics of these pearls remain largely unknown, particularly the thickness of the nacre and the spatial distributions of organic pigment in the nacre. Herein, using X-ray microradiography analysis, field-emission scanning electron microscopy, and Raman spectroscopy, we comprehensively investigated the internal fine-microstructural characteristics of typical colored Edison pearls. Our results indicated that Edison pearls have a typical core–shell structure, in which the core is the nucellus and the shell is the nacre. Average nacre thicknesses varied from 1.00 to 3.60 mm among specimens. Surprisingly, theoretical calculations showed that nacre accounted for about 50–90% of the whole pearl by volume. In addition, multiple prismatic or irregular structures, almost entirely composed of aragonite, coexisted in the nacre of some Edison pearls; one of these structures was closely adjacent to the nucleus. Interestingly, the average thickness of individual aragonite tablets in the nacre gradually decreased from the inner nacre (near the nucleus) to the outer nacre (near the pearl surface). Finally, the intensity ratios of the two peaks in the Raman spectra (I1124–1134/I1085) were non-uniform across nacre regions, and generally increased with distance from the nucleus. This pattern was directly attributed to variations in pigment content among nacre regions. Our results substantially increase our understanding of nacre biomineralization and the gemological characteristics of colored Edison pearls. More importantly, this study identified certain characteristics that can be used to identify color-treated Edison pearls. [ABSTRACT FROM AUTHOR]

The efficient and rapid removal of organic dyes from wastewater remains a complex and challenging task. In this study, UiO-66-NH2 was prepared by solvothermal synthesis, and then, UiO-66-NS was prepared by compounding l-cysteine with UiO-66-NH2 via the Ugi reaction for the efficient removal of methyl orange. UiO-66-NS was prepared by the addition of 1 mmol l-cysteine and showed good adsorption of methyl orange with 92.00% removal. Pseudo-second-order kinetics and Langmuir isotherms more accurately described the adsorption process of UiO-66-NS on methyl orange, which indicated that the adsorption process was dominated by monolayer adsorption of chemical reactions, and the maximum adsorption amounts of UiO-66-NS on methyl orange were 242.72 mg/g at 298 K. In addition, UiO-66-NS exhibited ultrahigh stability in acidic, neutral, and alkaline media (pH = 3–10), but its adsorption of methyl orange after 5 cycles was only 59.53% of the maximum adsorption amount. The adsorption mechanism is primarily electrostatic adsorption of UiO-66-NS with methyl orange, hydrogen bonding, and π-π interactions. This atomically economical Ugi multicomponent reaction provides new ideas for the preparation of structurally designable adsorbents with excellent performance. [ABSTRACT FROM AUTHOR]

Sida rhombifolia leaf extract was used to synthesize heterostructured nanocomposites Ag@CuO/ZnO and Ag@CuO/SnO2 by sol–gel combustion method followed by calcination. Through this ecofriendly approach, we could minimize the utilization of toxic chemicals as the bioactive components present in the plant extract act as capping and complexing agents. XRD studies indicated the formation of various crystalline phases of the congeners of the heterostructured nanocomposites. FESEM studies revealed irregular aggregates for AZC of particle size between 100 and 500 nm whereas uniformly arranged distorted spheres for ASC. The UV-DRS spectra helped to assess the reduced band gap energy from tau plot. The PL emission peaks of ZnO and SnO2 point towards the crystal defects in their lattices. The as-prepared ternary nanocomposites have resistivity to the growth of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeroginosa, Streptococcus mutans and Staphylococcus aureus with greater inhibition zones which showed their superior antibacterial activity. They are proved to be excellent photocatalysts for the degradation of hazardous organic dyes into harmless products and reduction of aromatic compounds into useful chemicals. Thus, the facile, low-cost and environmentally sustainable green synthesis provides Ag@CuO/ZnO and Ag@CuO/SnO2 nanocomposites with multifunctional efficacy. [ABSTRACT FROM AUTHOR]

In the present work, CdTe/ZnS high luminescence quantum dots (QDs) were synthesized by a facile, fast, one-pot, and room temperature photochemical method. Synthesized QDs were characterized by different structural and optical analyses such as X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform-infrared spectroscopy (FT-IR), Raman, photoluminescence (PL) and UV–visible (UV–vis) spectroscopies. The results confirmed the successful growth of the ZnS shell and formation of CdTe/ZnS core/shell structure. CdTe/ZnS prepared QDs indicated a PL quantum yield of about 51%. These high luminescence QDs were used for detection of Hg2+ ions in aqueous media, as catalyst for photodegradation of different organic dyes, and as antibacterial material for the inhibition of bacterial growth. PL intensity of the CdTe/ZnS QDs was completely quenched after addition of 1 m molar Hg2+in to the media. Photocatalyst activity of CdTe/ZnS QDs was studied by rhodamine b, methylene blue, and methylene orange as organic dyes under both the sun and UV illuminations, and results showed that CdTe/ZnS QDs had the best photocatalyst activity for methylene blue degradation under UV irradiation and radical scavenger results indicated that electrons have a main role in photodegradation of methylene blue dye by CdTe/ZnS QDs under UV illumination. Antibacterial effects of CdTe/ZnS QDs evaluated by Minimum Inhibitory Concentration (MIC), and Minimum Bactericidal Concentration (MBC) methods against two strains of bacteria. The results of the antibacterial test showed that CdTe/ZnS could inhibit bacterial growth in Bacillus cereus (Gram-positive) and Escherichia coli (Gram-negative G) bacteria. [ABSTRACT FROM AUTHOR]

A new photosensitizer 1-WS55 (dyad) based on two dyes with excellent properties, azulenocyanine (1) and WS55, is proposed at the density functional theory level (M06/def2-SVP). 1 is a dye having a broad NIR absorption (~ 1000 nm), and WS55 is a metal-free organic dye that presents a huge photoelectric conversion efficiency (PCE) of 9.5%. The dyad presents a panchromatic absorption along the UV–Vis-NIR region. It exhibits two intense Q bands (880, 926 nm) in the NIR region, one strong band (672 nm) in the visible region, and several bands in 300–600 nm. Charge transfer bands in the dyad from 1 to WS55 were found in the visible region, which favors the adsorption on an anatase TiO2 surface. The interaction energies dyad (dye)-TiO2 were calculated as a periodic system and corrected by the basis set superposition error. These show better adsorption for the dyad than fragments 1 and WS55. The electron injection calculated from the dye (dyad) to TiO2 suggests an efficient solar energy conversion because of ΔGinj > 0.2 eV. Additionally, calculations performed for the reorganization energy of electrons and holes indicate that the dyad presents the highest charge mobility. In summary, the dyad proposed 1-WS55 constitutes an excellent candidate to be used as a potential photosensitizer for the DSSCs. [ABSTRACT FROM AUTHOR]

In present work, films of CeO2-MnO2 NPs doped PEO-PVP blend have been prepared for photodegradation of organic dyes with low cost, high activity, anti-aggregation and low concentration of nanoparticles compare with other works. The structure, optical and photodegradation characteristics of PEO/PVP/CeO2/MnO2 nanostructures have been studied. The optical properties of PEO/PVP/CeO2/MnO2 nanostructures were studied in the wavelength range (220–720) nm. The results demonstrated that improvement in the structure and optical characteristics with the increase in CeO2/MnO2 NPs. The absorbance increased about 51% while the optical conductivity increased with about 33% with adding of 4.5 wt.% CeO2/MnO2 NPs, this behavior make it use in photodegradation of organic dyes. The refractive index, transmittance, energy gap and real dielectric constants of blend are changed with the increase in CeO2/MnO2 NPs, this behavior is suitable to use in low cost and electronics and optics devices. The allowed and forbidden energy gap of PEO/PVP blend decreased about 45% and 35% respectively with adding of 4.5 wt.% CeO2/MnO2 NPs. The results of photodegradation displayed excellent activity against organic pollutants. [ABSTRACT FROM AUTHOR]

Nowadays, the pollution relating to organic dyes imposes many endangering risk on the aqueous ecosystems and mankind. There is a raising interest in the purification of synthetic dyes-polluted waters by the advanced technologies. Herein, we reported the direct and facile synthesis of N-doped porous carbons by pyrolyzing ZIF-8 as a self-sacrificial precursor for removing a wide range of synthetic dyes involving crystal violet, Congo red, malachite green, methyl orange. N-doped porous carbons were featured by some advanced analytic techniques. Moreover, the influence of pyrolyzing temperature (600–800 °C), adsorption time (0–180 min), and dyes content (10–100 mg/L) on uptake capacity on N-doped porous carbons was optimized. Nonlinearized kinetic and isotherm fittings aided to more understand the nature of organic dyes uptake. The highlight outcome indicated the presence of vital surface functional groups such as phenolic, carboxyl, lactone, and basic groups on N-doped porous carbon. Adsorption kinetics indicated the adherence of both pseudo-first-order equation, and pseudo-second-order equations. Equilibrium uptake of crystal violet, Congo red, as well as methyl orange, obeyed Langmuir model, while that of malachite green followed Freundlich model. With five cycle recyclability and sufficient adsorption capacity, N-doped porous carbon may be a suitable adsorbent for removing organic dyes in water. [ABSTRACT FROM AUTHOR]

Multifunctional hybrid hydrogels based on chitosan (CS) and poly(vinyl alcohol) (PVA), chemically crosslinked with genipin (GEN), and filled with multi-walled carbon nanotubes (MWCNTs) were synthesized and characterized to be used as dye adsorbents in polluted water. Solutions (10 - 5 M) of methyl orange (MO) and acid blue 113 (AB) were tested. Each dye solution was analyzed in initial acid and basic pH conditions (pH 6.02 ± 0.2 and 10.0 ± 0.4). The physicochemical, mechanical properties, dye removal efficiency, adsorption kinetics, and possible hybrid hydrogels' adsorption mechanism were examined. Incorporating GEN enhanced the polymeric network structure and the mechanical stability of CS/PVA-based hydrogels; their elastic modulus increased to ninefold even in aqueous acid media. The CS/PVA/GEN and CS/PVA/GEN/MWCNTs hydrogels presented removal efficiencies up to 96.8% and 93.2% (0.30 and 0.36 mg/g) for MO and 90–100% (0.70–0.77 mg/g) for AB. Regardless of the initial pH value of the dye solutions, all of them presented a final value of pH ~ 5, which implies that electrostatic attractions can occur during the adsorption process. Experimental data were successfully fitted to pseudo-first-order kinetics. Thus, physisorption processes acted during the removal of MO and AB. FT-IR spectroscopy demonstrated that the hydrogel's amino (–NH 2 ) and hydroxyl (–OH) groups are mainly involved in adsorption by electrostatic interactions, hydrogen bonding, n– π stacking interactions, and π – π interactions. We demonstrated that using GEN and MWCNTs in the CS/PVA blend offers a useful approach for getting resistant, efficient, and low-cost adsorbent materials to successfully deal with water pollution caused by anionic organic dyes as MO and AB, among others. [ABSTRACT FROM AUTHOR]

In present research, we designed the novel CuS–CdS/ZnO ternary nanophotocatalysts with various weight percentages of ZnO (80 and 90 wt%) via one-pot sono-hydrothermal method. These nanocomposites efficiently use the sunlight irradiation as a neat and endless energy resource, reduce the recombination rate of the photo-produced e−–h+ pairs, and increase ZnO photocatalytic performance. Furthermore, we synthesized CdS/ZnO, CuS/ZnO, CuS–CdS, and their bare samples and compared their photocatalytic activities with the as-prepared ternary nanophotocatalysts. Fabricated nanophotocatalysts were characterized via X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX), Brunauer–Emmett–Teller (BET) surface area and Barrett–Joyner–Halenda (BJH) pore size and volume analyses, diffuse reflectance spectroscopy (DRS), and point of zero charge pH (pHpzc). Surprisingly, the synthesized ternary nanophotocatalyst with 90 wt% of ZnO (CuS–CdS/ZnO(90)) had the highest photocatalytic activity compared to the other prepared nanophotocatalysts. It removed 97.1% of methylene blue in 140 min. Therefore, using the ternary structure has led to the outstanding photocatalytic performance under simulated sunlight illumination. Additionally, the photodegradation of various dyes, the influence of initial pH solution, and reusability of the optimum photocatalyst were verified in this study. [ABSTRACT FROM AUTHOR]

Nickel–aluminum-layered double-hydroxide (Ni–Al LDH) was synthesized via a facile and green route of co-precipitation. Systematic characterizations of the synthesized material were done by different instrumental techniques. The morphology of the Ni–Al nanomaterial was observed to be sheet-like structures as indicated by FESEM images. From the XRD measurements, it was confirmed that the as-grown nanosheets were Ni–Al LDH nanomaterials with a small quantity of aluminum oxide. Further, the Ni–Al LDH nanomaterial was tested as a photocatalyst for the solar and adsorption-assisted removal of organic pollutants from wastewater. Organic compounds of acridine orange (AO), methyl orange (MO) and cresyl blue (CB) were used as model organic pollutants in this study. Among the three dyes, the Ni–Al photocatalyst was found best for the MO removal while performing the reaction under the dark and visible light conditions. During experiments, it was found that Ni–Al LDH decolorized the MO containing wastewater up to 50% by the process of adsorption performed in the dark conditions. The decolorization efficiency was increased under the visible light as 87% decolorization of MO was achieved from its 0.03 mM solution due to the dye degradation by the action of Ni–Al LDH as a photocatalyst. [ABSTRACT FROM AUTHOR]

In 60 min, microwave-synthesized ZrO2/ZnO heterostructures exhibited high and fast sunlight photodegradation efficiencies for 50 ppm Congo red (CR) and 50 ppm methylene blue (MB) pollutants. ZrO2/ZnO heterostructures were characterized by XRD, SEM, EDX, FTIR, and diffuse reflectance (DR) techniques. The XRD analysis showed that these heterostructures have combined components of tetragonal ZrO2 and hexagonal ZnO phases. The SEM micrographs of all ZrO2/ZnO nanocomposites demonstrate the formation of nanospherical particles (major) and rod-like (minor) structures. The EDX spectra verified the presence of Zr, Zn and O elements with percentage ratios equivalent or close to that used during the experimental preparation. The FT-IR spectra showed the vibrational characteristic absorption modes of ZrO2 and ZnO bonds around 400–600 cm−1. Two band gap energies were estimated corresponding to ZrO2 (5.05–5.16 eV) and ZnO (3.1–3.16 eV) components. Remarkably, in presence of ZrO2/ZnO (30/70 at%) heterostructure, the free solar energy initiated photodegradation efficiencies of 87% and 98% for 50 ppm CR and 50 ppm MB dyes after 60 min, respectively, which indicates the fast and superior photocatalytic activity of microwave-synthesized ZrO2/ZnO heterostructure. As well, this composition reveals good reusability and stability for three photocatalytic cycles. This uppermost photodegradation performance can be assigned to the high separation of charge carriers, especially for the ZrO2/ZnO (30/70 at%) nanocomposite. Highlights: Microwave assisted-hydrothermal ZrO2/ZnO heterostructures. ZrO2/ZnO heterostructure exhibits fast and superior sunlight catalytic activity. Efficiency of 87% and 98% for removal of 50 ppm Congo red and methylene blue. High separation of photo-generated electron hole pairs. [ABSTRACT FROM AUTHOR]

In this research, the treatment of methylene blue (MB) dye wastewater by a novel system that combines H2O2 with an aluminum-carbon micro-electrolysis (ACE) was explored. The effects of the H2O2 amount, initial pH, aluminum to carbon ratio, total aluminum-carbon mass, dye concentration, and reaction temperature on degradation of MB were investigated. The findings revealed that under the following conditions: H2O2 34.0 mg/L, initial pH of 3.0, aluminum-to-carbon ratio of 2:1, total aluminum-carbon mass of 2.0 g/L, MB concentration of 20 mg/L, and 20 °C, the degradation rate of MB could reach 99.3% after 180 min, which is 18.4% more compared with ACE at the same conditions without H2O2. Through the quenching experiments, it was proved that the efficient free radicals produced during degradation are •OH and •O2-. Finally, a possible mechanism of H2O2 enhanced aluminum carbon micro-electrolysis (HP-ACE) for MB degradation was discussed. [ABSTRACT FROM AUTHOR]

Achieving an ideal light-harvesting system at a low cost remains a challenge. Herein, we report the synthesis of a hybrid dye system based on tetraphenylene (TPE) encapsulated organic dyes in a continuous flow microreactor. The composite dye nanoparticles (NPs) are synthesized based on supramolecular self-assembly to achieve the co-emission of aggregation-induced emission dyes and aggregation-caused quenching dyes (CEAA). Numerical simulations and molecular spectroscopy were used to investigate the synthesis mechanism of the CEAA dyes. Nanoparticles of CEAA dyes provide a platform for efficient cascade Förster resonance energy transfer (FRET). Composite dye nanoparticles of TPE and Nile red (NiR) are synthesized for an ideal light-harvesting system using coumarin 6 (C-6) as an energy intermediate. The light-harvesting system has a considerable red-shift distance (~126 nm), high energy-transfer efficiency (ΦET) of 99.37%, and an antenna effect of 26.23. Finally, the versatility of the preparation method and the diversity of CEAA dyes are demonstrated. Developing efficient light harvesting systems at low cost is a challenge. Here, the authors synthesized coemissive dyes in a continuous flow microreactor featuring a controlled cascade FRET process combining aggregation-induced emission and quenching. [ABSTRACT FROM AUTHOR]

The presence of composite in the nanofluid resultant is essential to provide a significant methylene blue (MB) removal property in industrial waste water. Silver oxide (Ag2O) nanoparticles (NPs) placed over zinc oxide (ZnO) NPs had a significant increase in photocatalytic activity. The Ag2O NPs doped ZnO NPs were synthesised in the current study by utilising Millingtonia hortensis flower extract and a simple green synthesis procedure. The floral extract is a fantastic reducing and stabilizing agent. ZnO has been doped along with Ag2O Nanofluid (NF) (volumes of ZnO 10 ml, 15 ml, 20 ml, and 25 ml). The crystalline nature of the produced material was investigated using powder XRD analysis. To confirm the presence of silver in nanofluids, the EDAX spectrum and UV–Vis spectral analysis were employed. The EDAX spectrum established the materials' compositions, while the FESEM analysis revealed the various surface morphologies of the generated materials. ZnO/Ag2O (NPs) catalysts degraded the organic dye MB. ZnO/Ag2O NPs (25 ml Ag2O NF) degrade at a rate of 63 percent after 120 min of irradiation, due to their large surface area. The typical particle size of synthesised nanoparticles is 16–17 nm. The photocatalytic activities are enhanced when particles from the flower are extracted, according to the characterization data. [ABSTRACT FROM AUTHOR]

The photocatalytic activity of three solvothermal prepared steel slag nanocomposites, SSNP-10, SSNP-20, and SSNP-30, was tested in this work for methylene blue (MB) dye degradation. Using SSNP for the first time, the photocatalytic degradation of MB dye was optimized using Box–Behnken design (BBD) in a response surface approach. The influence of essential operating parameters was experimentally examined, modeled, and optimized. The analysis of variance (ANOVA) results revealed that the suggested quadratic models significantly agreed with the experimental investigation, with p-values less than 0.0001 and an R2 value of 0.9914. Accordingly, the optimized conditions were 32.83 mg catalyst dose, 11.42 pH, 41.34 min irradiation times, and 10.63 mg/L MB dye concentration. The optimized degradation efficiency of the MB dye was 89.43% under these conditions. The result was experimentally validated with the optimal operating parameters for SSNP-10, SSNP-20, and SSNP-30, and the photodegradation efficiencies were 90.07%, 88.94%, and 87.28%, respectively. A pseudo-first-order reaction kinetics of 0.0293, 0.0291, and 0.0267 was achieved for SSNP-10, SSNP-20, and SSNP-30 with a regression coefficient of 0.9514, 0.9312, and 0.9042, respectively. According to Pareto analysis, the operational factors that had the greatest effect on dye degradation efficiency were catalyst dosage (F-value 585.32) > MB concentration (F-value 423.89) > irradiation period (F-value 368.01) > pH (F-value 362.34). The results showed that the SSNP catalyst was the key parameter for the generation of hydroxyl radicals responsible for the photodegradation of MB dye and may be useful for other contaminants' degradation. [ABSTRACT FROM AUTHOR]

In this study, XRD, SEM, TEM, PL, EIS and other characterization methods were used to study the morphology, electron–hole pair recombination efficiency and photocarrier migration rate of the compsite, and analyze the degradation of methylene blue (100 mg/L). Zn0.5Cd0.5S and MoS2 form heterojunction structure, the band gap width decreases a lot, the absorption of visible light is greatly enhanced, the electron–hole recombination efficiency also decreases a lot, and the electron migration rate becomes faster. In the process of photocatalytic degradation of high concentration methylene blue (100 mg/L), the degradation effect of 3%-Zn0.5Cd0.5S/MoS2 is the best, reaching 98.46%, and the degradation rate was 0.0243 min−1. O2−·played a major role in the photocatalytic degradation process. [ABSTRACT FROM AUTHOR]

Herein, a magnetic chromium-based metal–organic framework (MOF) was successfully synthesized and applied for adsorption and removal of methylene blue MB and methyl orange MO from an aqueous solution. To achieve high adsorption capacity and selective removal of organic dyes, rational surface functionalization of synthesized MOF with poly (propylene imine) PPI dendrimer was carried out. The Fe3O4@MIL-101@PPI composite exhibits a crystalline structure with high thermal stability and magnetic properties. In addition, this framework shows a high specific surface area (116 m2/g) and porosity which is beneficial for wastewater treatment. The results indicate that Fe3O4@MIL-101@PPI composite can remove cationic dye from an aqueous solution more selectively and efficiently than anionic dye. The adsorption experiments revealed high adsorption capacity (93.9 mg/g) and fast adsorption kinetics following the pseudo-second-order kinetic model. Interestingly, the regeneration study showed that the Fe3O4@MIL-101@PPI composite had appropriate reusability for dye removal with an almost unchanged structure after five regeneration cycles. This research provides new insights for the rational design of hybrid magnetic adsorbents with synergistic functionality and porous structure by combining the advantages of magnetic nanoparticles, MOFs, and dendrimers. [ABSTRACT FROM AUTHOR]

Incautious discharge of organic dyes such as methyl orange (MO) has produced serious pollution to the environment, calling for the efficient techniques to remove them with retaining the green world. The photo-catalytic degradation of organic dyes is promising among the developed techniques. Thus, a strategy based on transpiration-prompted photocatalytic degradation of dye pollutant under sunlight is put forward. Aniline (ANI) is graft-polymerized onto poly(acrylamide-co-N-4-aminophenylacrylamide) (PAAm) cryogel embedded with gold nanoparticles (AuNPs, diameter: 4–10 nm). The obtained cryogels integrated with AuNPs and PANI inside PAAm matrix (AuNP@PAAm-g-PANI) have been structurally explored based on the chemical composition and the phase/porous morphology. SEM and TEM observation shows that PANI and AuNPs are uniformly distributed in PAAm matrix. Since the macro-porosity of cryogel, hydrophilicity of PAAm and photo-thermal activity of PANI, PAAm-g-PANI cryogels without AuNPs can have a photo-thermal evaporation rate of water at 1.63 kg·m−2·h−1. As a comparison, AuNP@PAAm-g-PANI cryogels with AuNPs exhibit higher one at 2.20 kg·m−2·h−1, suggesting the promotion of AuNPs to photo-thermal evaporation. Meanwhile, PANI appreciatively assists AuNPs to display higher catalytic ability for the oxidative degradation of MO. Therefore, the removal of MO from water is obviously prompted by the water transpiration under sunlight with AuNP@PAAm-g-PANI cryogels, whose rate constant can reach to 0.320 h−1, being three folds of that for the sole absorption of MO. This transpiration-prompted photocatalytic degradation provides a fascinating route to eliminate organic pollutants and obtain pure water from wastewater simultaneously with sustainable sunlight energy. [ABSTRACT FROM AUTHOR]

PVC membrane was synthesized and its hydrophobicity was investigated by dehydrochlorination in alkaline condition, the addition of tween 60 surfactant and nanoclay. The synthesized membranes were analyzed using the contact angle, FTIR, FE-SEM, EDX, TGA and AFM techniques. High density of membranes was shown by FESEM images. Furthermore, the analysis of AFM revealed that dehydrochlorination can be caused to decrease surface roughness from 117 to 74.9 nm. However, the addition of Tween 60 and nanoclay to membrane increased surface roughness. Results showed that the PVC membrane with pore size of 100 nm is a nanofiltration membrane. The flux of initial membrane was 0.036 mL cm−2 s−1 which increased to 0.058 mL cm−2 s−1 in PVC/nanoClay/Tween 60 membranes. The performance of PVC/nanoClay/Tween 60 membrane was studied in Dead-End membrane systems for removal of BO2 from aqueous solution. Based on the results, dye removal efficiency was 90% under the conditions of 4 bar pressure, room temperature, 20 mg L−1 BO2 concentration, neutral pH and time of 1 h. [ABSTRACT FROM AUTHOR]

With the millions of dyes being used in textile industries, there is a challenge for humanity to remediate the waste fluid emerged from these industries and provide a solution to protect the natural water around us. In this context, we report the manufacturing process to develop nanofunctionalized, electroformed tube for the degradation of Azo dyes which are considered as poorly biodegradable industrial pollutants. Copper/graphene oxide electroform tubes have been developed via in-house pulse electroforming setup. Vertically grown ZnO nanorods were synthesized over electroformed electroform tube via chemical synthesis route and were characterized using scanning electron microscopy, energy dispersive spectroscopy, X-ray diffractometer, UV–Vis diffuse reflectance spectrophotometer, and microhardness test. The as-synthesized substrates were utilized for photodegradation of organic dyes under sunlight irradiation. The targeted dyes for evaluation of photocatalytic efficiency are methyl orange (MO), and methylene blue (MB). The results reveal that copper/graphene–zinc oxide electroform tubes provides higher photodegradation efficiency 98.24% in 120 min for MO, and 98.95% in 135 min for MB dye. The proposed functional composite platform can be envisioned for scaling it up for large volume waste water treatment in textile industries. [ABSTRACT FROM AUTHOR]

In spite of the efficient redox properties of CeO2 originating from the easy inter-conversion of the Ce4+/Ce3+ couple, its large band gap (~ 3 eV) limits its photocatalytic application. Herein, we report a novel one-pot method to synthesize phase-pure Mn-doped CeO2 nanoparticles (average size ~ 7 nm) well dispersed in a network of carbon nanotubes (CNT) and also attached onto the CNT surface, as confirmed by transmission electron micrographs. The Mn and CNT content in ceria were optimised based on ability for synergistic sorptive-photocatalytic removal of a model cationic dye under UV–visible light. Diffuse reflectance spectra revealed narrowed optical band gap (only ~ 1.8 eV) in the optimised visible light active Mn-CeO2/CNT nanohybrid resulting from increased defect states due to multivalent Mn dopants (confirmed by X-ray photoelectron spectroscopy). N2 adsorption–desorption data confirmed large increase in the specific surface area compared to ceria nanoparticles leading to improved dye adsorption. The arrest of recombination of photogenerated carriers (suggested by photoluminescence quenching) due to conductive CNT support further contribute to enhancing photocatalytic activity. Thus, the findings presented in this article are relevant to materials research for environmental remediation from a surface and band gap engineering point of view. [ABSTRACT FROM AUTHOR]

A novel soft-chemical synthesis method was used to synthesis nanostructured α-Bi2O3. The method uses chitosan (Cs) and sodium alginate (Alg) as directing agents, representing an environmentally friendly approach that has not been explored previously for this oxide. The impact of these biopolymers on the formation of α-Bi2O3 is thoroughly examined using the precipitation method. The resulting α-Bi2O3 catalysts are characterized using FTIR, XRD, UV/Vis, EDX, SEM, and BET techniques, and they are subsequently utilized for the photocatalytic degradation of Acid Orange 7 (AO7). It is found that both α-Bi2O3-Cs and α-Bi2O3-Alg photocatalysts demonstrate remarkable stability and high photocatalytic activity in degrading AO7 under both ultraviolet-B and visible light. Notably, 90% dye removal at a pH of 6.31 is achieved by α-Bi2O3-Cs without the need for further pH adjustment, contrasting with the 55% achieved by α-Bi2O3-Alg. The pollutant's decomposition was confirmed through LC–MS analysis. Furthermore, the influence of the templating agent on the morphology of the photocatalyst and its efficiency in photodegradation is observed. Optimization studies utilizing Central Composite Design (CCD) and degradation kinetics were reported. Additionally, the adsorption mechanism of AO7 on α-Bi2O3 catalyst is investigated using Density Functional Theory (DFT), and Fukui functions are employed to predict photocatalytic degradation. The consistency between DFT findings and experimental results enhances the comprehension of the mechanisms involved in AO7 dye degradation using α-Bi2O3 catalysts.Graphical Abstract: A novel soft-chemical synthesis method was used to synthesis nanostructured α-Bi2O3. The method uses chitosan (Cs) and sodium alginate (Alg) as directing agents, representing an environmentally friendly approach that has not been explored previously for this oxide. The impact of these biopolymers on the formation of α-Bi2O3 is thoroughly examined using the precipitation method. The resulting α-Bi2O3 catalysts are characterized using FTIR, XRD, UV/Vis, EDX, SEM, and BET techniques, and they are subsequently utilized for the photocatalytic degradation of Acid Orange 7 (AO7). It is found that both α-Bi2O3-Cs and α-Bi2O3-Alg photocatalysts demonstrate remarkable stability and high photocatalytic activity in degrading AO7 under both ultraviolet-B and visible light. Notably, 90% dye removal at a pH of 6.31 is achieved by α-Bi2O3-Cs without the need for further pH adjustment, contrasting with the 55% achieved by α-Bi2O3-Alg. The pollutant's decomposition was confirmed through LC–MS analysis. Furthermore, the influence of the templating agent on the morphology of the photocatalyst and its efficiency in photodegradation is observed. Optimization studies utilizing Central Composite Design (CCD) and degradation kinetics were reported. Additionally, the adsorption mechanism of AO7 on α-Bi2O3 catalyst is investigated using Density Functional Theory (DFT), and Fukui functions are employed to predict photocatalytic degradation. The consistency between DFT findings and experimental results enhances the comprehension of the mechanisms involved in AO7 dye degradation using α-Bi2O3 catalysts. [ABSTRACT FROM AUTHOR]

Organic dyes pollution has caused significant threat to flora, fauna and humans because the toxic of dyes. In this work, with the help of acetic acid as a defect initiator, the hierarchical porous MIL-101(HP-MIL-101) has been synthesized and used for removing anionic dyes Eosin y (EY), Methyl orange (MO), Congo red (CR) and Acid fuchsin (AF) from water. Due to its positive surface charge, larger specific surface area, well-matched pore structure, and the charge, size, and diameter of dyes, HP-MIL-101 showed rapid adsorption and an excellent maximum adsorption capacity of 425 and 336 mg⋅g− 1 for CR and AF, respectively. A series of batch experiments were carried out to investigate the impact of various key factors, including adsorption duration, initial dye concentration, and temperature. In addition, the kinetics, isotherm, and thermodynamics about the adsorption properties were also discussed. In addition, HP-MIL-101 showed stable and high reusability for at least three cycles, with an efficiency of over 95% without significant structural changes. This study highlights the potential of hierarchical porous MOF for mitigating dye pollution and advancing sustainable water treatment methodologies. [ABSTRACT FROM AUTHOR]

Manganese oxide loaded on activated alumina beads (MnOx/AABs) was prepared by one-pot hydrothermal method and applied to activate periodate (PI) towards the degradation of Rhodamine B (RhB) and other organic dyes. The catalyst was first characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and N2 sorption. Subsequently, the effects of catalyst dosage, oxidant dosage, initial pH as well as co-existing inorganic anion and humic acid on the performance of the MnOx/AABs/PI system were studied. Under optimum conditions (catalyst dosage = 15 beads, PI dosage = 0.2 g/L), the removal efficiency of 50 mg/L RhB reached 99.4%, with a total organic carbon removal efficiency of 51.0%. The removal efficiencies of several other organic dyes were in the range of 70%-95.1%. The leached amount of Mn was measured to be 0.027 mg/L. Mechanism studies revealed that 1O2, IO3⋅ and O2⋅− were identified to be responsible in this reaction system, and 1O2 played a decisive role. In addition, IO4− was converted to IO3− without other toxic products during the degradation process. Reusability test in both the batch and continuous modes showed that the catalyst could be efficiency regenerated by calcination. Combining the results of liquid chromatography-mass spectrometry (LC–MS) and density functional theory calculations, the possible degradation pathway of RhB was proposed. Finally, toxicity evaluation of the degradation products of RhB was performed by theoretical calculations as well as experimental tests with Vigna radiata.Graphical Abstract: Manganese oxide loaded on activated alumina beads (MnOx/AABs) was prepared by one-pot hydrothermal method and applied to activate periodate (PI) towards the degradation of Rhodamine B (RhB) and other organic dyes. The catalyst was first characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and N2 sorption. Subsequently, the effects of catalyst dosage, oxidant dosage, initial pH as well as co-existing inorganic anion and humic acid on the performance of the MnOx/AABs/PI system were studied. Under optimum conditions (catalyst dosage = 15 beads, PI dosage = 0.2 g/L), the removal efficiency of 50 mg/L RhB reached 99.4%, with a total organic carbon removal efficiency of 51.0%. The removal efficiencies of several other organic dyes were in the range of 70%-95.1%. The leached amount of Mn was measured to be 0.027 mg/L. Mechanism studies revealed that 1O2, IO3⋅ and O2⋅− were identified to be responsible in this reaction system, and 1O2 played a decisive role. In addition, IO4− was converted to IO3− without other toxic products during the degradation process. Reusability test in both the batch and continuous modes showed that the catalyst could be efficiency regenerated by calcination. Combining the results of liquid chromatography-mass spectrometry (LC–MS) and density functional theory calculations, the possible degradation pathway of RhB was proposed. Finally, toxicity evaluation of the degradation products of RhB was performed by theoretical calculations as well as experimental tests with Vigna radiata. [ABSTRACT FROM AUTHOR]

The unregulated industrializations has poses serious threat to entire ecosystem by releasing untreated effluents containing hazardous dyes to fresh water. In the forefront polycationic ferrite (ternary ferrite)-chitosan microspheres were used to address the issue of synthetic dyes, contaminating water bodies. In the current study, visible light assisted ternary ferrite Fe2Ni0.5Cu0.5O4 (CNF-NPs) photocatalyst along with their binary ferrite photocatalysts Fe2CuO4 (CF-NPs) and Fe2NiO4 (NF-NPs) were prepared by a facile approach to compare the efficiency of ternary and binary ferrites photocatalysts for degradation of dye. Additionally, chitosan was used to support ferrites, and different chitosan-supported ternary ferrite microspheres (CNF-CM) and binary ferrite microspheres (CF-CM and NF-CM), were tailored respectively. FTIR analysis of CNF-CM composites shows presence of all the characteristics peaks of chitosan and CNF NPs confirming its synthesis. The calculated average crystallite size (18 nm) were obtained from Scherrer's equation applied to XRD data. The composition of CNF-NPs was confirmed by EDX analysis. The CNF-CM has 860 μm microsphere size with a smooth surface as shown in SEM images. The calculated optical band gap of the synthesized photocattalyst lies in visible region (2.01) obtained from Tauc’s plot. The photocatalyst CNF-CM showed 93% degradation efficiency for hazardous methylene blue (MB) and 90% efficiency for rhodamine b (RB) dyes within 140 min of sunlight irradiation at optimum conditions. Inorder to validate the photocatalytic efficiency of the CNF-CM, the experimental conditions were also optimized by statistical optimization methods (RSM, ANN). The ANOVA adequate precision (AP) value of 17.83 (> 4) for MB and 16.91 for RB suggests that the projected output variable range is relatively larger compared to the average standard error, further affirming the competence of the quadratic model. [ABSTRACT FROM AUTHOR]

This research explores the synthesis, characterization, and application of Vanadium Pentoxide nanoparticles (V2O5 NPs), focusing on their efficacy in the photocatalytic degradation of organic dyes under visible light. Utilizing a co-precipitation method, we synthesized V2O5 NPs characterized by an orthorhombic crystal structure with a consistent average particle size of 28 nm. The optical properties of V2O5 NPs, including their band gap, were thoroughly investigated to understand their light absorption capabilities, which are crucial for photocatalytic activity. In our study, Methyl Violet (MV) dye was employed as a model organic pollutant to assess the photocatalytic performance of the nanoparticles. Under visible light irradiation, the V2O5 nanoparticles demonstrated an exceptional photocatalytic degradation efficiency, achieving up to 85% degradation of the MV dye within 100 min. This high level of efficiency is attributed to the nanoparticles’ ability to effectively absorb visible light and generate electron-hole pairs, thereby facilitating a robust degradation process. Further analysis revealed that the photocatalytic activity led to the generation of reactive oxygen species (ROS) such as superoxide and hydroxyl radicals, which are integral to the dye degradation mechanism. These ROS play a critical role in breaking down the dye molecules, significantly contributing to the overall effectiveness of the photocatalytic process. The results of this study highlight the potential of V2O5 nanoparticles as a sustainable and effective photocatalytic material for environmental remediation applications, particularly in the treatment of wastewater containing organic dyes. This research not only advances our understanding of the photocatalytic properties of V2O5 nanoparticles but also demonstrates their practical application in addressing environmental pollution through innovative and efficient degradation of hazardous substances. [ABSTRACT FROM AUTHOR]

In our present study, the photocatalytic degradation of malachite green (MG) an organic dye was carried out using a phycocyanin extract of Spirulina platensis under the irradiation of sunlight. The aim of the present study is to incorporate a simple, novel, an eco-friendly, and cost-effective degradation of dyes without using any harmful metals and chemicals. It was observed that 25 ppm of MG dye got degraded nearly to 100 % at 3 h. The UV absorbance studies indicate the absence of a peak at 620 nm which is a conclusive evidence for MG dye degradation. An optimization study of MG dye degradation was evaluated by Response Surface Methodology using Minitab module 20.4.0.0 statistical software and its percentage of degradation was statistically analyzed using analystat. The FT-IR studies of raw spectra show minimal variation; however, the deconvoluted spectra in the region of 1600–1700 cm−1 indicate the variation in the secondary structure of amide I bands that leads to the dye degradation. The dye degradation study mainly follows the first-order kinetics between the time intervals of 60–180 min. The characteristics of degraded water were assessed by a TOC analyzer. The value of total inorganic carbon (TIC) in MG before treatment was 90 mg/L and seems to be slightly high when compared to MG after treatment which was found to be 87.65 mg/L and the adsorbent-treated water with a low value of 54.25 mg/L. These results well matched with the characteristics of normal water. The presence of phycocyanin in the degraded water was effectively removed by treating with activated carbon and it was confirmed with fluorescence analysis. These results support that the MG dye degradation was exhibited by phycocyanin extract and bio-mimics the quantum dot photocatalytic activity. [ABSTRACT FROM AUTHOR]

This study deals with the toxicity of the treated solutions of two types of dyes, namely, the anthraquinonic Reactive Bleu 19 dye (RB19) and the bi-azoic Direct Red 227 dye (DR227), which are treated in single and binary mixture systems. The target molecules were removed by the photocatalysis process using ZnO as a catalyst, which was calcined at two temperatures 250 and 420 °C (ZnO250 and ZnO420) prepared in the lab by the one-step calcination method. XRD, TEM, EDX, XPS, FT-IR, BET, RAMAN, and EPR analyses were carried out to characterize the catalyst material. While the phytotoxicity was being conducted using watercress seeds, the cytotoxicity took place using a cell line (raw) and an intestinal cell (caco-2). The XRD analysis showed the partial calcination of ZnO250 and the presence of anhydrous zinc acetate along with the ZnO nanoparticles (NPs). This result was not observed for ZnO420. Despite the complete discoloration (100%) of all the final solutions, ZnO250 exhibited a high cytotoxicity and phytotoxicity against the RB19 dye after the photocatalytic treatment; however, it was not the case of ZnO420 which was selected as an eco-friendly photocatalyst for the degradation of organic dyes based on the results of removal efficiency, cytotoxicity, and phytotoxicity. [ABSTRACT FROM AUTHOR]

Excessive discharge of toxic dyes is detrimental to ecological system and human health. Therefore, an effective photocatalyst must be designed and developed to degrade dyes from wastewater. Herein, a novel one-dimensional (1D) flower-like recoverable ZnFe2O4/C/MnO2/BiOI magnetic composite photocatalyst was synthesized via electrospinning technique combined with hydrothermal method. The photocatalytic activities of composite photocatalyst were evaluated by degrading methyl orange (MO) and Rhodamine B (RhB) under simulated light irradiation. The efficiency of ZnFe2O4/C/MnO2/BiOI photocatalyst in visible light for 150 min reached 91% (MO) and 120 min reached 94% (RhB). Moreover, the degradation rate of MO still remained 78% after five cycles. The design of 1D magnetic flower-like composite provided a new strategy for preparing photocatalysts possessing excellent photocatalytic efficiency and cyclic stability. [ABSTRACT FROM AUTHOR]

A novel cyanine 3 (Cy3)-based bio-conjugated sensor has been developed to detect target DNA or extracted RNA from COVID -19 samples using the fluorescence resonance energy transfer (FRET) experiment. A special sequence of the COVID -19 genome was selected as a complementary DNA (target DNA) part. The opposite chain of this target sequence was designed in 2 parts; one part was attached to the Cy3 organic dye (capture DNA or Cy3- DNA), and the other part was attached to the BHQ2 molecule (quencher DNA or BHQ2- DNA). The Cy3 molecule acts as a donor pair, and BHQ2 acts as an acceptor pair in the FRET experiment. The capture DNA and quencher DNA can form a sandwiched complex in the presence of target DNA. The formation of the entitled sandwiched hybrid causes the decrement of emission intensity of the Cy3 donor in bio-conjugated Cy3-DNA via energy transfer from Cy3 (as a donor) to BHQ2 (as an acceptor). Indeed, in the presence of non-complementary DNA, the pairing of DNA strands does not occur, the FRET phenomenon does not exist, and therefore fluorescence intensity of Cy3 does not decrease. Moreover, this biosensor was successfully applied to analyze real samples containing extracted RNA of COVID -19 prepared for the reverse transcriptase-polymerase chain reaction (RT-PCR) test, and the results were promising. [ABSTRACT FROM AUTHOR]

The series of dyes derived from the fluorescein "2–(3–hydroxy–6–oxo–6Hxanthene–9–yl) benzoic acid" with introduction of different acceptor functional groups at the para position were designed as material sensitizers for solar cells. DFT and TD–DFT with B3LYP hybrid function at 6–31G (d,p) basis set were simulated to investigate the significant properties of all isolated dyes together with utilizing a Lanl2DZ basis set of titanium atom of dyes adsorbed on a TiO2 as complex systems in the gas phase at the ground and excited state. The resulted values of electronic parameters such as HOMO, LUMO levels, energy gap and dipole moment of the dyes can be employed to improve the efficient dyes of solar cell. The range of the energy of HOMO was from − 4.903 to − 6.258 eV, LUMO from − 3.010 to − 2.727 eV, the energy gab from 3.539 to 1.926 eV, and the dipole moment from 9.306 to 11.627 Debye of all dyes. The calculated data demonstrated better electronic properties, driving force, chemically reactivity, open–circuit photo-voltage, redox, light harvesting efficiency, oscillator strength, light absorption spectra, electron injection, oxidation potential energy and electron regeneration. Moreover, the favored dye charge transfer and adsorption process on model, including dye–oxide couple (Ti(OH)3H2O) was examined. The calculations which were based on the DFT method showed excellent photoelectric conversion efficiency and strong binding of the dyes on the surface of TiO2. Additionally, there is a probability that the electron injection process happening from each examined molecule to the conduction band of TiO2 and the succeeding regeneration. As a result, the theoretical results can be useful for to synthesize novel, highly photo– effective materials and can play the significant role of sensitizers in DSSC applications. [ABSTRACT FROM AUTHOR]

In this research, four novel push-pull organic dyes with D–π–A structural configuration with a variety of π-spacer segments were investigated from the structural, electronic, optical and photovoltaic characteristics viewpoints, using density functional theory approaches. In fact, we modulated the π-spacer segment by inserting C–C double and triple bonds and phenyl and anthracene units to examine the further improvements in the light-harvesting capability of these dyes in dye-sensitized solar cells (DSSCs). It was corroborated that using C–C triple bond in conjunction with phenyl group as π-linker will reduce the light-harvesting efficiency values in comparison with C–C double bond group, leading to the lower power conversion efficiency of DSSCs. In this context, we made a revision and presented a newly designed dye structure by inserting anthracene together with C–C triple bond and investigated their notable planar π-conjugation effect as an excellent candidate for DSSCs applications. [ABSTRACT FROM AUTHOR]

Excess aluminum (Al) is a stressful condition that affects plant growth and yield quality. This study evaluates growth responses and changes in the contents of photosynthetic pigments and organic solute in maize (Zea mays L.) plants inoculated with Trichoderma asperelloides isolates (T01, T02, T74, T76, or T96) and treated with increasing doses of Al (0, 50, 100, 150, and 200 µM of Al). Uninoculated unstressed plants served as control. Absolute growth rate, root length, dry biomass (shoot, roots and total) and shoot:root ratio were significantly affected in Al-stressed maize plants inoculated with T. asperelloides. Also, chlorophylls (a, b and total) were significantly reduced, whereas carotenoids and anthocyanins increased in those plants. Except for carotenoids, all parameters increased in plants inoculated with T. asperelloides, especially T01 or T02 isolates. Anthocyanins increased by 50% in plants inoculated with T74 and treated with 100 or 150 µM Al as compared to control plants. Total soluble carbohydrates increased by 74% and 101% in plants inoculated with T74 and T76, respectively, and treated with 200 µM Al. Total free amino acids increased more than 50% in plants inoculated with T02 and treated with 150 and 200 µM Al. Free prolines increased by 90%, 145% and 165% in plants inoculated with T74 and treated 100, 150 and 200 µM Al, respectively, in comparison to the unstressed control plants. We concluded that T. asperelloides positively affected growth, photosynthetic pigments, and organic solutes of Al-stressed plants, especially those inoculated with T01, T02, or T74 isolates. [ABSTRACT FROM AUTHOR]

Novel organic dyes system containing responsible group for using in dye-sensitized solar cells and effective anchoring group for improving interaction between dye (photosensitizers) and nanolayer were designed and prepared. All intermediates and organic dyes were purified and analyzed using analytical techniques. The results confirmed the structure of intermediates and organic dyes. Dye-coated TiO2 and ZnO semiconductors were used for the preparation of the photoanode. The synthesized dyes were trapped in J-aggregation, reflected J-aggregation, and red shift in UV–Vis spectra of dyes in solution relative to the coated on nanomaterials. Cyclic voltammetry and DFT methods were used to evaluate the energy levels of the synthesized compounds. Dye-sensitized solar cells were also prepared and evaluated under standard conditions, using the synthesized compounds. The efficiency of Dye 8 as photosensitizer on TiO2 and ZnO was 6.65% and 6.37%, respectively. [ABSTRACT FROM AUTHOR]

A new series of metal-free organic dyes (SM1-5) with dual anchors are synthesized for application in dye-sensitized solar cells (DSSC). Here, a simple triphenylamine (TPA) moiety serves as the electron donor, while di-cyanoacrylamide and di-thiazolidine-5-one units serve as the electron acceptors and anchoring groups. To understand the effect of dye structure on the photovoltaic characteristics of DSSCs, the photophysical and electrochemical properties, as well as molecular geometries calculated from density functional theory (DFT), are used for dyes SM1-5. The extinction coefficients of the organic dyes SM1-5 are high (5.36–9.54 104 M−1 cm−1), indicating a high aptitude for light harvesting. The photovoltaic studies indicated that using dye SM4 as a sensitizer showed a power conversion efficiency (PCE) of 6.09% (JSC = 14.13 mA cm−2, VOC = 0.624 V, FF = 68.89%). Interestingly, SM4 showed the highest values of VOC among all dyes, including N-719, due to its maximum dye coverage on the TiO2 surface, enhancing charge recombination resistance in the sensitized cell. The good agreement between the theoretically and experimentally obtained data indicates that the energy functional and basis set employed in this study can be successfully utilized to predict new photosensitizers' absorption spectra with great precision before synthesis. Also, these results show that bi-anchoring molecules have a lot of potentials to improve the overall performance of dye-sensitized solar cells. [ABSTRACT FROM AUTHOR]

Enzymes are extensively used as catalyst in several fields of production such as chemistry, and pharmaceuticals owing to their selectivity, efficiency and environmentally friendliness. However, their applications are often hindered due to their insufficient stability and difficulties in re-use. As a member of porous crystalline materials, metal organic frameworks are a promising enzyme carrier due to their multi-functional pore surfaces and robustness in variety of harsh conditions. In this study, the horseradish peroxidase (HRP) enzyme was immobilized onto UiO-66-NH2 (Universitetet i Oslo) by a facile incubation method at the room temperature to improve the stability and reusability of enzyme. The prepared HRP@UiO-66-NH2 bio-composite was characterized by using FT-IR, XRD and SEM. The crystal structure of MOF was well-preserved after enzyme immobilization. A colorimetric assay for enzyme activity after released from UiO-66-NH2 has been employed based on the catalytic oxidation of phenol coupled with 4-aminoantipyrine. The robustness and activity of immobilized enzyme after released from UiO-66-NH2 were investigated by biodegradation of methyl orange (MO) and methylene blue (MB) with several parameters such as pH, temperature, the dosage of H2O2 and the dye concentration with comparison to its free form. The optimum condition for dye degradation was obtained at basic conditions. The immobilized enzyme maintained its activity at elevated temperature while free enzyme lost its activity at the same conditions, attributed to the armoring effect of UiO-66-NH2. According to the results of studied various parameters, MO and MB were biodegraded to 60% and 45%, respectively, within 60 min with the optimum conditions at pH 9 and 50 °C at a H2O2 dosage of 3%. The superior pH tolerance and stability suggest potential of UiO-66-NH2 immobilized peroxidase enzyme in industrial applications. [ABSTRACT FROM AUTHOR]