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This critical review points out the most serious and problematic issues to be found in the literature on the adsorption of dyes on clay minerals. The introduction draws attention to the fundamental problems, namely the insufficient characterization of adsorbents, the influence of impurities on the adsorption of dyes, and the choice of inappropriate models for the description of the very complex systems that clay minerals and their systems represent. This paper discusses the main processes accompanying adsorption in colloidal systems of clay minerals. The relationship between the stability of the colloidal systems and the adsorption of dye molecules is analyzed. The usual methodological procedures for determining and evaluating the adsorption of dyes are critically reviewed. A brief overview and examples of modified clay minerals and complex systems for the adsorption of organic dyes are summarized. This review is a guide for avoiding some faults in characterizing the adsorption of organic dyes on clay minerals, to improve the procedure for determining adsorption, to evaluate results correctly, and to find an appropriate theoretical interpretation. The main message of this article is a critical analysis of the current state of the research in this field, but at the same time, it is a guide on how to avoid the most common problems and mistakes. [ABSTRACT FROM AUTHOR]

Coordination polymers (CPs) are a diverse class of multi-dimensional compounds that show promise as photocatalysts for degrading dyes in polluted water. Herein, a new 1D Cd(II)-based coordination polymer with the formula [Cd(bpyp)(nba)2] (1) (bpyp = 2,5-bis(pyrid-4-yl)pyridine and Hnba = 4-nitrobenzoic acid) is synthesized and characterized. In 1, the two carboxyl groups of two different nba− ligands show μ2-η1:η1 and μ1-η1:η1 coordination modes to connect the CdII centers and sit on either side of the chain along the b direction. The produced CP 1 was utilized as the photocatalyst in the process of the photodegradation of methyl blue (MB), methyl orange (MO), rhodamine B (RhB), and methyl violet (MV) dyes when exposed to UV light. The photocatalytic degradation activities of CP 1 were analyzed, and the results suggest that it exhibits an extraordinary efficiency in the degradation of MB, MV, MO, and RhB. RhB has a 95.52% efficiency of degradation, whereas MV has a 58.92% efficiency, MO has 35.44%, and MB has 29.24%. The photodecomposition of dyes is catalyzed mostly by •O2− and •OH−, as shown by research involving the trapping of radicals. [ABSTRACT FROM AUTHOR]

In summary, the study demonstrates that the photodegradation of methylene blue is influenced by the effective surface charge and colloidal stability of TiO SB 2 sb nanoparticles in aqueous solutions. Designing Highly Active S-g-C 3 N 4 /Te@NiS Ternary Nanocomposites for Antimicrobial Perfo... This research focused on the synthesis of pure nickel sulfide (NiS) nanoparticles, Te-doped NiS nanoparticles (Te@NiS), and nanocomposites combining sulfur-doped g-C SB 3 sb N SB 4 sb (S-g-C SB 3 sb N SB 4 sb ) and Te@NiS through a hydrothermal process. Preparation and Real-World Applications of Titania Composite Materials for Photocatalytic... This article discusses potential applications of the semiconducting transition metal oxide titanium dioxide (TiO SB 2 sb ), which is a cost-effective and non-toxic material known for its excellent photocatalytic properties. Synergistic Correlation in the Colloidal Properties of TiO 2 Nanoparticles and Its Impact... This study explores the relationship between the photodegradation rate of methylene blue (MB) and the effective surface charge of titania nanoparticles (TiO SB 2 sb NPs) in an aqueous solution. [Extracted from the article]

Dye-contaminated water from industry is hazardous to human and aquatic lives. Membrane technology is considered a viable approach to resolve the issue. Herein, copper oxide nanoparticles (CuO NPs) embedded in porous chitosan membranes have been prepared using a solution-casting approach with sodium tripolyphosphate as a crosslinker and polyethylene glycol as a porogen. The prepared membranes have been characterized by physicochemical, mechanical and photocatalytic properties. FTIR results indicate some hydrogen bonding across CuO NPs and the chitosan matrix. XRD and TGA analyses reveal that the membranes are thermally stable and somehow crystalline. SEM examination indicates that the membrane surfaces express porous/roughened texture. The contact angle measurement indicates that the pure chitosan and CuO NPs-embedded membranes are hydrophobic, whereas PEG-leached porous chitosan membranes express hydrophilicity. CuO NPs reinforcement has significantly improved the tensile strength, whereas the elongation at break decreased. The CuO NPs incorporated in chitosan membranes exhibit exceptional photocatalytic activities against methyl orange and methylene blue dyes for their effective removal from aqueous media. [ABSTRACT FROM AUTHOR]

The problem of industrial dyes depollution has pushed the scientific research community to identify novel photocatalysts with high performance. Herein, new photocatalysts composed of BaTiO3, BaTi0.96Cu0.04O3, BaTi0.96Cu0.02V0.02O3 and BaTi0.96Cu0.02Nb0.02O3 powders were prepared by solid-state reaction. The structural analysis of the samples confirmed the formation of the BaTiO3 structure. The splitting of (002) and (200) planes verified the formation of the tetragonal phase. The XRD peaks shifted, and the unit cell volume expansion verified the substitution of the Ti4+ site by Cu2+, V4+ and Nb5+ ions. The morphological measurements showed that the addition of (Cu, V) and (Cu, Nb) ions changes the particles' morphology of BaTiO3, reducing its grains size. After the incorporation of (Cu, V) and (Cu, Nb) ions, the band gap of BaTiO3 was reduced from 3.2 to 2.84 and 2.72 eV, respectively. The modification of BaTiO3 by (Cu, Nb) ions induced superior photocatalytic properties for methyl green and methyl orange with degradation efficiencies of 97% and 94% during 60 and 90 min under sunlight irradiation, respectively. The total organic carbon results indicated that the BaTi0.96Cu0.02Nb0.02O3 catalyst has a high mineralization efficiency. In addition, it possesses a high stability during three cycles. The high photodegradation efficiency of Bi0.96La0.02Gd0.02FeO3 was related to the wide-ranging visible light absorption. [ABSTRACT FROM AUTHOR]

In this work, seven organic dyes were designed (M2–M7) to have the D-π1-Ai-π2-A structure from the reference dye M1, which has the D-π1-π2-A structure. By inserting different auxiliary acceptors Ai (i = 1–7) between the π1 and π2 onto the reference dye M1, we obtained the designed dyes to study their photovoltaic properties for use in DSSC devices. The geometrical structures, absorption spectrum properties, nonlinear optical properties (NLOs), energy levels, frontier molecular orbitals, and some photovoltaic parameters were theoretically investigated using density function theory (DFT) and time-dependent DFT (TD-DFT) methods, with the aim of improving the DSSC performance of the designed dyes. The theoretical results reveal that the designed dyes would be used as potential sensitizers in DSSCs due to their very small energy gaps, broad absorption spectra, higher NLO properties, lower reorganization energy (λtot), lower regeneration driving force (ΔGreg), longer excited lifetime (τ), higher vertical dipole moment (µnormal), reasonable electron injection driving force (∆Ginj), and equally reasonable light-harvesting efficiency (LHE) compared to the reference dye M1. Furthermore, the designed dyes (M2–M8) have better charge transferability, the highest stabilization energy, and the highest ability of electron-donating and electron-accepting, resulting in a high short-circuit current and better power conversion energy (PCE) compared to reference dye M1. These results show that the introduction of different auxiliary acceptors Ai can most effectively improve the photovoltaic performance of our system. [ABSTRACT FROM AUTHOR]

Pollution by organic dyes has received extensive attention due to their high toxicity, biohazard, and high stability in the natural environment, and the development of high‐efficiency dye degradation and heavy metal ion reduction technologies is urgently needed in photocatalysis. However, the interface microenvironment between catalyst and pollutant is often ignored, and the poor compatibility of the catalyst‐pollutant interface constrains further efficient catalysis. Herein, to improve the compatibility of the catalyst‐pollutant interface, a surfactant‐capping strategy for enhanced photocatalysis of rhodamine B (RhB) on one‐dimensional rod‐like Bi2S3 nanocrystals was investigated. Specifically, polyvinylpyrrolidone (PVP)‐capped Bi2S3 (Bi2S3‐PVP) showed enhanced RhB degradation rate compared with pure Bi2S3, and further studies suggested enhanced reaction interface compatibility at the Bi2S3‐PVP‐RhB interface. This work provides an interface microenvironment modulation strategy for improving photocatalytic performance towards organic dyes. [ABSTRACT FROM AUTHOR]

Electrospun nanofiber mats have a high specific surface area and very small pores which can be tailored by the spinning process. They are thus highly suitable as filters for small particles and molecules, such as organic dyes. On the other hand, they are usually very thin and thus have low mechanical properties. As a potential reinforcement, mycelium of Pleurotus ostreatus was grown on poly(acrylonitrile) nanofiber mats and thermally solidified after fully covering the nanofiber mats. This study investigates whether the filtration efficiency of the nanofiber mats is altered by the mycelium growing through it and whether the mechanical properties of the nanofibrous filters can be improved in this way. The study shows fast and reliable growth of the mycelium on the nanofiber mats and high filtration efficiency for astra blue and chlorophyll, while indigo carmine showed only very low filtration efficiency of up to 20%. For chlorophyll and safranin, membranes with mycelium showed higher filtration than pure nanofiber mats. In diffusion cell tests, especially astra blue was strongly adsorbed on the membranes with mycelium. [ABSTRACT FROM AUTHOR]

In this study, a novel hydroxyapatite (HAp)‐based composite, Co‐Cu/ZIF@HAp, was constructed through in situ growth and simultaneous sonication followed by magnetic string. Herein, the HAp‐based nanocomposite was obtained in which HAp was coated with cobalt–copper bimetallic zeolitic imidazolate framework (ZIF) in one‐pot synthesis method. The as‐synthesized composite was characterized by PXRD, FTIR, FE‐SEM, EDS, HR‐TEM, TGA‐DTG, XPS, BET, and UV‐DRS techniques, which suggested that HAp was well coated with bimetallic ZIF. The prepared composite was utilized as a catalyst in degradation of organic pollutants. Removal of organic pollutants such as organic dyes has become indispensable due to their higher stability, toxicity, and mutagenic nature. Two commonly found organic dyes, namely, Eosin Yellow (EY) and Brilliant Green (BG), were chosen for the investigation of photocatalytic activity of the as‐prepared catalyst. The degradation process was carried out under solar radiation, and there was no utilization of any oxidizing and reducing agent. Several parameters such as amount of catalyst dose, initial concentration of the dye solution, and effect of different pH conditions were evaluated for better understanding of photocatalytic performance of Co‐Cu/ZIF@HAp composite. Both EY and BG dyes were almost degraded up to 98.3% and 99.5%, respectively, within 50 min by the as‐prepared nanocomposite. Also, quenching test was performed that confirmed the formation of superoxide radicals (O2−.) as reactive oxygen species (ROS) in the photodegradation process. The as‐synthesized catalyst was repeatedly used for five times to ascertain the stability and reusability of catalyst. [ABSTRACT FROM AUTHOR]

Synergistic effects in bimetallic catalysts produce a catalyst with superior activity than a monometallic component. In this work, a novel magnetic crosslinked copoly(ionic liquid) nanohydrogel was synthesized and employed for the stabilization of AuCo bimetallic nanoparticles (Fe3O4@PolyIL‐AuCo). This material was characterized using different instrumental techniques such as FT‐IR, TGA, XPS, VSM, solid‐state UV–Vis, SEM mapping, and TEM. Results indicated a narrow size distribution of nanoparticles and high water dispersibility of Fe3O4@PolyIL‐AuCo. Using this catalyst, a series of nitroarenes were reduced to the corresponding amines in aqueous media. In addition, organic dyes were efficiently degraded by this catalyst. Different experiments dealing with the same transformation confirmed that Fe3O4@PolyIL‐AuCo exhibited higher catalytic activity than the similar monometallic Au and Co catalysts. This catalyst was recycled for at least 11 consecutive runs with very small deactivation, and TEM, VSM, and XPS confirmed the stability of the reused catalyst. [ABSTRACT FROM AUTHOR]

This study reports the synthesis of a new composite material, polyaniline cobalt chloride (PAni)–(CoCl2), in powder form via a chemical method at room temperature, with varying weight percentages of the alkyl salt CoCl2 (5, 10, 20, and 40 wt%). The goal of this research is to enhance the physicochemical, magnetic, and electrical properties of the material. Cyclic voltammetry experiments confirmed the electrochemical activity of the PAni-CoCl2 electrode. The PAni-5% CoCl2 composite showed better results in electrochemical impedance spectroscopy (EIS) measurements than the PAni-10% CoCl2 and PAni-20% CoCl2 composites. Magnetization, X-ray diffraction (XRD), UV-vis, and Fourier transform infrared (FTIR) spectroscopy revealed a strong interaction between Co2+ and PAni chains, confirming the formation of a PAni/CoCl2 nanocomposite. The ferromagnetic polyaniline-cobalt chloride composite was used as an absorbent in environmental applications such as the removal of an organic dye, which in our study is methylene blue. [ABSTRACT FROM AUTHOR]

The organic dyes that have been added to water by various industrial effluents possess a serious threat to the environment due to their mutagenic character. TiO2 has been widely employed as a photocatalysis for the degradation of these dyes. However, a non-metal doped TiO2 can be a promising candidate for the advanced treatment of industrial wastewater containing organic dyes. In this work, we have prepared and tested different boron-doped TiO2 photocatalysts to examine the effect of boron addition on the photocatalytic activity of TiO2. The various boron precursors used are boric acid (BA), boron oxide (BO), and boron nitride (BN), through which Boron is formulated and is doped through a single-step sol-gel method. The prepared nanocomposites are characterized using various characterization techniques, such as Field Emission Scanning Electron Microscopy (FESEM), Transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis) and Raman spectroscopy, X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy, photoluminescence, and X-ray Photoelectron Spectroscopy (XPS) analysis. UV light of wavelength 365 nm has been used for studying the photocatalyst behavior. Both rhodamine-B (RhB) and industrial wastewater samples have been studied for degradation kinetics. The boron-doped TiO2 nanocomposites show a high level of dye degradation (>95%) with RhB dye and (>63%) with industrial wastewater samples. Further, TiO2-BA composites in both the cases showed maximum dye degradation compared with other boron nanocomposites with an enhancement in the efficiency of (>13%) over a pure phase of TiO2. [ABSTRACT FROM AUTHOR]

The latest developments in the adsorption of organic dyes by adsorbents (metal oxides, modified metal oxides) were addressed in this review study. The main goal of this paper is to sort out the dispersion information of adsorbent materials, which are often employed in organic dye adsorption. The review dedicated to the specific dyes adsorption using various adsorbent (metal oxides, modified metal oxides). The review covers the adsorption process including parameters, kinetics, and isotherms. The review gives the brief information of Congo red (CR) adsorption using metal oxide nano‐adsorbents which provide readers with massive dye specific collection. For the first time, several metal‐doped materials that absorb organic dyes are summarized and addressed. The review includes adsorption of organic dyes using single metal oxide, bimetallic oxide, trimetallic oxide, and modified metal oxide. This study also summarized the effects of critical factors such as pH, initial dye concentration, adsorbent dosage, contact time, and temperature on dye adsorption utilizing metal oxide nano‐adsorbents. In addition, the kinetic and applied isotherm models have been discussed. Finally, a few recommendations are made for further research on adsorbent materials. [ABSTRACT FROM AUTHOR]

Here, the zinc sulfide–copper sulfide (ZnS–CuS) nanocomposites have been synthesized using immersing thin layers of ZnS in 0.5 (M) Copper (II) chloride solution at low temperature by a simple and cost-effective chemical bath deposition (CBD) method. The immersion time of ZnS thin films in copper (II) chloride solution was investigated based on the structural, morphological, optical and optical catalytic activity of the prepared layers. The results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the formation of CuS: ZnS nanolayers consists of nanocrystals with an approximate diameter of less than 10 nm during the immersion time of 1 min. The particles forming the layers are dense and have good adhesion to the substrate. The energy gap of the layers decreases with increasing copper, which can lead to phase formation. Their significant photocatalytic activities in the photodegradation of Rhodamine B (RhB) dye in aqueous media have been considered, because ZnS:CuS nanocomposite thin films showed light catalytic activity in the RhB degradation in presence of visible radiation, so that the percentage of dye degradation is decreased by increasing the amount of copper and the duration of exposure to visible light due to slowing down the recombination rate of electron–hole pairs. While investigating the optical catalytic activity of the layers, there was no need to homogenize and centrifuge the solution to separate the nanoparticles from it. The main aim of this study is consideration of the effects of CuS amount on the photocatalytic activity of ZnS–CuS nanocomposite under the CBD method of synthesis condition. [ABSTRACT FROM AUTHOR]

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

Bismuth MOF catalysts were successfully fabricated using the solvothermal method, which involved the use of a mixed solvent composed of DMF and ethanol in varying volume ratios. Subsequently, the catalysts underwent comprehensive characterization using diverse techniques i.e., FTIR, XRD, N2 adsorption-desorption, UV–vis diffuse, and SEM-EDX. The photocatalytic degradation of RhB was investigated using six different bismuth MOF (BiEt) catalysts. Later, parametric analysis study was performed to test the BiEt catalysts under different values of pH, Rhodamine B (RhB) dye concentrations, and different scavengers. The results showed that BiEt1 had total surface area of 16.78 m2/g and pore volume of 0.025 cm3/g with a pore size of 1.5331 nm. The photocatalytic performance of the catalysts was assessed by quantifying the removal capacity and analyzing theUV–vis absorption spectra during the degradation of RhB. The results show that BiEt 1 had the highest photodegradation efficiency toward the RhB and that it required the shortest time of 60 min to achieve 100% removal. The UV–vis absorption spectra of BiEt catalysts during the degradation of RhB showed that the characteristic absorption wavelength of RhB was observed at 576 nm. These findings suggest that the prepared BiEt was an exceptional photocatalyst for the degradation of RhB. It has great potential for environmental remediation applications. [Display omitted] • Bismuth MOF catalysts revealed exceptional photocatalytic performance, achieving 100% removal of RhB dye within 60 min. • BiEt1 exhibited highest removal capacity of RhB and possessed a total surface area of 16.78 m2/g. • DMF/ethanol solvent mixture improved the photocatalytic efficiency. • The pH significantly influenced the photocatalytic activity of Bi-BTC catalysts. • Scavengers hindered efficiency of RhB degradation. [ABSTRACT FROM AUTHOR]

The presence of dyes in effluents from textile industries has a detrimental effect on aquatic ecosystems as it hinders the process of photosynthesis by reducing the penetration of sunlight. The adsorption capacity of a carbon foam-based iron oxide sorbent obtained from natural sources for the removal of organic methylene blue (MB) dye from water was investigated. The adsorption capacities were examined by batch experiments, wherein the impacts of varying iron content, sorbent dosage, contact time, dye concentration, and characterization were assessed. The physical characteristics and surface morphology of the synthesized carbon foam were also investigated. The carbon precursor and iron oxide precursor were coalesced within a singular container and subjected to carbonization process. This resulted in the formation of a porous structure that is capable of effectively providing support to the iron oxide particles. The carbon foam produced is a self-assembled formation that possesses the characteristic shape and underlying network structure reminiscent of bread. As the number of nanoparticles went up, so did the number of active sites. At elevated temperatures, the interactions between the dye molecules were enhanced, resulting in a more efficient process of dye removal. The magnetite sample exhibited endothermic adsorption, and all other samples exhibited exothermic adsorption. The adsorption of MB onto iron supported by carbon foam did not exhibit intraparticle diffusion as the only rate-limiting step for all samples. The adsorption rate was governed by a multistep elementary reaction mechanism in which multiple processes occurred simultaneously. The experimental data in this study may be accurately modeled by the pseudo-second-order kinetic model (R2 > 0.96). Additionally, the Freundlich isotherm best describes the adsorption equilibrium, which is supported by the outstanding fit of data to the model (R2 > 0.999). The findings suggest that the utilization of a natural carbon foam as a support for an immobilized iron oxide sorbent demonstrates considerable effectiveness in the removal of methylene dye from industrial effluent. [ABSTRACT FROM AUTHOR]

ZnO/carbon composites were prepared via hydrothermal method and carbonization using zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and glucose (C6H12O6) as zinc and carbon source, and ammonia as precipitation agent. The effects of glucose addition amount on the morphology and structure of ZnO/carbon composites were discussed. The chemical composition, morphology and structures of ZnO/carbon composites were characterized by XRD, FESEM, TG and Raman spectroscopy. The flower-like ZnO/carbon nanoparticle composites were obtained after carbonization at 600 °C for 2 h. The carbon content in ZnO/carbon composites increased with the increase of glucose, and the carbon content reached 28.8% when the glucose was 1.0 g. As the carbon content increases, carbon nanoparticles change from irregular particles to spherical particles, while the degree of graphitization of carbon in ZnO/carbon composites has not significant change. The photocatalytic performances of ZnO/carbon composites were studied by degradation of organic dye [rhodamine B (RhB) and methylene blue (MB)] under UV light irradiation, and the maximum degradation rate of RhB and MB reached 93.3% and 97.2%, respectively. [ABSTRACT FROM AUTHOR]

The ferroelectric Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZTO) ceramic particles were immobilized in a polymer matrix of polyvinylidene difluoride (PVDF) in order to fabricate flexible and stable composite films for the treatment of water using the piezocatalysis process. The content of BCZTO in BCZTO/PVDF composite films was 0, 5, and 10 wt. % of PVDF. The presence of the BCZTO phase in PVDF composites was confirmed using x-ray diffraction, Raman spectroscopy, and a scanning electron microscope. Piezocatalytic activity of BCZTO/PVDF composite films was investigated by monitoring the degradation of various organic dyes, pharmaceuticals, and bacteria present in the water. The highest values of dye degradation were achieved in 10 wt. % BCZTO/PVDF composite films, where the model dyes named methylene blue, Rhodamine B, and methyl orange dyes were degraded by ∼91%, ∼86%, and 90% after the sonication for 180 min, respectively. The dye degradation performance using piezocatalysis was found to be repeatable and consistent for up to five cycles. Hydroxyl radical (⋅OH) was identified to be the main reactive species behind piezocatalytic dye degradation. An increment in dye degradation performance was observed with an increment in the power of the ultrasonicator during piezocatalysis. In addition, 10 wt. % BCZTO/PVDF composite films displayed 59% and 50% degradation of pharmaceutical antibiotics named tetracycline and ciprofloxacin, respectively, within 180 min of sonication, respectively. Also, more than 99.99% E. coli bacteria were inactivated using 10 wt. % BCZTO/PVDF composite films under 180 min of sonication treatment and showed a bacterial log reduction of 3.4. These promising results indicate the 10 wt. % BCZTO/PVDF composite film as a potential candidate for the treatment of water using piezocatalysis technology. [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]

A critical challenge that impedes the application of photocatalytic techniques for organic dye degradation from polluted industrial effluents is that traditional powdery photocatalysts exposed limited photo-absorption sites and exhibited inefficient recyclability. To overcome these challenges, this study designed a one-step process to synthesize a monolithic copper selenide (CuSe)-based photocatalyst. The characterization results fully supported that the maintenance of the copper foam during the selenization process was the prerequisite for the monolithic photocatalyst to keep its structural integrity in photocatalytic reactions. The surface of the monolithic photocatalyst fully covered by active CuSe is crucial for the exposure of photocatalytically active sites and the efficient degradation of methylene blue (MB). It was found that the CuSe-based monolithic photocatalyst exhibited excellent MB degradation performances under harsh pH conditions and high MB concentrations. From these perspectives, it is reasonable to conclude that the CuSe-based monolithic photocatalyst as prepared is a promising alternative to traditional powdery photocatalysts for organic dye degradation and industrial effluent cleaning. [ABSTRACT FROM AUTHOR]

In this work, successful nanocomposites composed of different ratios of reduced graphene oxide and copper sulphide (xCuS–rGO) were fabricated to aid in treating water contaminated with organic dyes. XRD, TEM, SEM, XPS, IR, EDX and BET were applied for the characterization of (CuS–rGO). The photocatalytic strength of the prepared nanocomposites was evaluated using artificial sunlight irradiation. The nanocomposites were tested for their ability to degrade both anionic and cationic organic dyes, including amaranth and rhodamine B (RhB). The excellent photocatalytic strength of our composites, relative to pristine CuS and rGO, was interpreted as rGO sheets being very porous. In addition, the charge moved efficiently from rGO to CuS. The combined properties enhanced the efficiency of photodegradation of CuS–rGO composite across the dyes under the illumination of simulated sunlight. The electron transportation from rGO sheets to the CuS conduction band enhances the charge separation and transportation. The role of superoxide radicals in photocatalytic degradation was unveiled and the interactions between the studied dyes and our catalysts were investigated by density functional theory study and scavenging investigation. This work gives new ideas about the preparation and properties of (CuS–rGO) composites and their broad application in solving environmental problems. [ABSTRACT FROM AUTHOR]

The construction of ternary TiO 2 NTs/Ag 3 PO 4 –AgBr photocatalysts was carried out by the SILAR deposition of Ag 3 PO 4 and AgBr on TiO 2 nanotube arrays (TiO 2 NTs) for enhancing the photocatalytic application in H 2 evolution and dyeing wastewater remediation. The adjustment of Ag 3 PO 4 /AgBr deposition cycles was used to optimize the optical absorption and photocatalytic property. The TiO 2 NTs/Ag 3 PO 4 –AgBr (5) prepared with 5 cycle deposition of Ag 3 PO 4 and AgBr exhibited the optimal photoelectric activity and photocatalytic performances. The photocatalytic rate constants for the degradation of MO, RhB and MB dyes achieved 1.35 × 10−2, 3.30 × 10−2 and 4.47 × 10−2 min−1, respectively, and the visible light-driven photocatalytic H 2 evolution rate achieves 46.87 μmol cm−2 h−1. •O 2 − radicals exhibited the key influence on the organic dye degradation, and the as-prepared photocatalysts showed exceedingly high photocatalytic activity and stability. Furthermore, the photocatalytic mechanism was proposed based on the ESR result. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) containing azobenzene building blocks carry great potential for use in intelligent storage, separation, chemical sensing, and catalysis due to their intriguing photo‐responsiveness. However, azobenzene units are often exploited as the linkers to form the framework of COFs, thereby restricting their molecular motion and photoisomerization. Herein, a simple yet robust template‐free solvothermal strategy is reported to yield azobenzene‐dangled COFs (Azo‐COFs) with their azobenzene moieties suspending within the pores. The crystallinity, specific surface area, and morphology of Azo‐COFs can be conveniently tailored by changing the ratio of amine to aldehyde monomers. Notably, the Azo‐COFs provide sufficient free space for the reversible trans‐to‐cis isomerization of the dangled azobenzene units inside the pores, thus reversibly regulating surface wettability of Azo‐COFs. The adsorption capacity of Azo‐COFs toward organic dye molecules is increased by 3.7‐fold when irradiated with ultraviolet light, which can be ascribed to the intelligent closing/opening of molecular gates rendered by photoisomerization of azobenzene moieties. As such, the ability to photoregulate the adsorption of Azo‐COFs highlights their significance in functioning as smart porous nanomaterials for applications in cargo release, molecular sieves, ion transport, energy conversion systems, and environmental remediation. [ABSTRACT FROM AUTHOR]

In this study, biocarbon was obtained from the waste material corn digest. Carbon adsorbents were obtained by physical activation of the precursor with CO2. Detailed physicochemical characterization of the biocarbon was carried out using low-temperature nitrogen adsorption/desorption, Boehm titration, zero-charge point (pHpzc) and iodine number. In addition, the sorption capacity of the biocarbon agents towards an aqueous solution of methylene blue and methyl red was determined, and the kinetics of the adsorption process were determined. The biocarbon adsorbents were characterized by an average developed specific surface area covering the range from 320 to 616 m2/g. The sorption capacity of the biocarbon adsorbents against methylene blue ranged from 40 mg/g to 146 mg/g, and for methyl red it covered the range from 31 mg/g to 113 mg/g. It was shown that the efficiency of organic dye removal by the obtained biocarbons depends on the initial concentration of the adsorbate solution, its mass, shaking rate, adsorbent–adsorbate contact time and temperature. The results obtained from the Langmuir and Freundlich kinetic models showed that the Langmuir model is the most suitable model for describing the adsorption of the studied pollutants on biocarbon. In turn, the adsorption kinetics of dyes is described according to the pseudo-second-order model. Adsorption studies also showed that as the process temperature increases, the removal efficiency of methylene blue and methyl red increases. [ABSTRACT FROM AUTHOR]

Unique nonlinear optical properties for converting low-energy incident light into high-energy radiation enable up-conversion materials to be employed in photocatalytic systems. An efficient near-infrared (NIR) response photocatalyst was successfully fabricated through a facile two-step method to load BiOBr on the Nd3+, Er3+@NaYF4 (NE@NYF) up-conversion material. The NE@NYF can transform NIR into visible and UV light and promote charge–energy transfer in the semiconductor. Consequently, the as-obtained photocatalysts exhibit excellent photodegradation performance for rhodamine B dye (RhB) and tetracycline (TC) organic pollutants. About 98.9% of the RhB was decomposed within 60 min with the 20% NE@NYF-B sample, outperforming the pristine BiOBr (61.9%). In addition, the 20% NE@NYF-B composite could decompose approximately 72.7% of the organic carbon during a 10 h reaction, which was almost two-fold more than that of BiOBr. Meanwhile, a possible charge transfer mechanism is proposed based on the recombination of electron–hole pairs and reactive oxygen species. This work provides a rational hybrid structure photocatalyst for improving photocatalytic performance in the broadband spectrum and provides a new strategy for NIR light utilization. [ABSTRACT FROM AUTHOR]

Nowadays, for environmental remediation, photocatalytic process involving graphene-based semiconductors is considered a very promising oxidation process for water treatment. In the present study, nanocomposite (Cu/Ni/rGO) has been synthesized by Dypsis lutescens leaf extract. Characterization of the sample was carried out by UV-visible spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Different parameters like contact time, nanocatalyst amount, dye concentration, effect of temperature. and pH factor were optimized to examine the maximum removal efficiency for dyes rhodamine B and alizarine R with and without visible light source. In both cases, i.e., with or without light, maximum removal was observed at 20 mg of nanocatalyst for 5 ppm concentration of both dyes at 45 °C temperature and pH 10 for rhodamine B and pH 4 for alizarine R, respectively with a 20 min contact time. Maximum removal of dyes 93% rhodamine B and 91% alizarine R were observed under a tungsten lamp as compared to without a tungsten lamp, i.e., 78% of RhB and 75% of AR from mixture solution of these dyes. To assess the rate of reaction, spontaneity, and nature of reaction thermodynamics, kinetics and adsorption isotherms were studied. Thermodynamic values indicated that both dyes depicted endothermic and spontaneous degradation processes. Isotherm data fitted best to a Freundlich isotherm, while results of kinetic studies of both dyes followed the pseudo 2nd order kinetic equation. In the end, scavenging radical studies concluded that hydroxyl radicals were the main active specie involved in the photocatalytic degradation process, and regeneration experiments resulted that Cu/Ni/rGO nanocomposites were re-utilized for about four times. [ABSTRACT FROM AUTHOR]

[Display omitted] Membrane-based technology is emerging as an efficient technique for wastewater treatment in recent years. Membranes made up of two-dimensional materials provide high selectivity and water flux compared to conventional polymeric membranes. Herein, we report the synthesis and use of MoSe 2 membrane for dye and drug separation in wastewater, mainly from textile and pharmaceutical industries. The as-prepared MoSe 2 membrane shows ∼ 100% rejection for organic dyes and ciprofloxacin drug with a water flux reaching up to ∼ 900 Lm-2h-1bar-1. Further, the MoSe 2 membrane shows lower NaCl rejection of ∼ 1.9% for the dye/salt mixture. The interlayer spacing in the MoSe 2 membrane allows the water molecules and ions from the salt to pass through freely but restricts the movement of large contaminants. The membrane is stable against the bovine albumin serum fouling with a flux recovery rate of 96%. It also shows good performance even in harsh environments (pH 3–10). To the best of our knowledge, the MoSe 2 membranes were fabricated for the first time for wastewater treatment application. The dye/salt separation performance of the MoSe 2 membrane is significantly better than several other membranes. This work highlights the promising potential for using two-dimensional materials for textile and pharmaceutical wastewater treatment. [ABSTRACT FROM AUTHOR]

Organic dye‐contained wastewater is a major threat to the global environment and public health. In this study, natural wood and MoS2 are combined to create effective photocatalysts for removing organic pollutants from water under light irradiation. The results show that the photocatalytic degradation activity of wood/MoS2 composites are obviously superior to that of natural wood under solar light as well as possess outstanding stability after three reaction cycles. The improvement in photocatalytic performance for photodegradation is primarily due to an increase in specific surface area and the introduction of catalytic active sites from the edge S, which favors adsorption of organic pollutants and accelerates the degradation process. The synergistic effect of adsorption and photocatalysis also ensures that the composited catalyst is highly universal in its application to organic dye degradation, including RhB (Rhodamine B), MB (Methylene Blue), and MO (Methyl Orange); the kinetic constant for the photocatalytic degradation of RhB, MO, and MB are 0.040, 0.035, and 0.032 min−1, respectively and the degradation performance can be well maintained after three cycle tests. Our study has proved that the wood/MoS2 composite is a novel, low‐cost photocatalyst that plays an important role in environmental protection. [ABSTRACT FROM AUTHOR]

Semiconducting nanomaterials based heterogeneous photocatalysis represent a low-cost, versatile technique for environmental remediation, including pollution mitigation, energy management and other environmental aspects. Herein, we demonstrate the syntheses of various heterogeneous photocatalysts based on highly reduced graphene oxide (HRG) and vanadium oxide (VOx)-based nanocomposites (HRG–VOx). Different shapes (rod, sheet and urchin forms) of VOx nanoparticles were successfully fabricated on the surface of HRG under solvo-/hydrothermal conditions by varying the amount of water and ethanol. The high concentration of water in the mixture resulted in the formation of rod-shaped VOx nanoparticles, whereas increasing the amount of ethanol led to the production of VOx sheets. The solvothermal condition using pure ethanol as solvent produced VOx nano-urchins on the surface of HRG. The as-prepared hybrid materials were characterized using various spectroscopic and microscopic techniques, including X-ray diffraction, UV–vis, FTIR, SEM and TEM analyses. The photocatalytic activities of different HRG–VOx nanocomposites were investigated for the photodegradation of methylene blue (MB) and methyl orange (MO). The experimental data revealed that all HRG–VOx composite-based photocatalysts demonstrated excellent performance toward the photocatalytic degradation of the organic dyes. Among all photocatalysts studied, the HRG–VOx nanocomposite consisting of urchin-shaped VOx nanoparticles (HRG–VOx-U) demonstrated superior photocatalytic properties towards the degradation of dyes. [ABSTRACT FROM AUTHOR]

The discovery of nanoparticles with varied size, shape and composition has stretched the limits of nanotechnology in almost any field. One of the important areas of interest is the use of nanoparticles in heterogeneous catalysis, whereby it offers an advantage by providing large surface area. Our present work focussed on the development of a graphene-based nanocatalyst (Pd@NGO) as an efficient tool to study various organic transformations. The prepared mesoporous catalyst was characterised by X-ray diffraction (PXRD), thermogravimetric analysis (TGA), field emission-scanning electron microscopy (FE-SEM), Brunauer–Emmett–Teller (BET), high resolution transmission electron microscopy (HR-TEM) and Fourier transformer infrared spectroscopy (FT-IR), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and X-ray photoelectron spectroscopy (XPS). TEM images showed the light grey sheets of N-GO on which Pd(0) nanoparticles were immobilised. BET analysis confirmed the mesoporous texture of the designed nanocatalyst by giving the surface area of 12.933 m2 g−1 with a pore volume and average pore diameter of 0.020685 cm3 g−1 and 6.39 nm, respectively. Also, FTIR data affirmed the presence of a characteristic C–N peak near 1271 cm−1 showing successful doping of nitrogen over graphene oxide. The XPS data revealed the presence of various elements like carbon (C 1s), nitrogen (N 1s), oxygen (O 1s) and Pd 3d. The prepared nanocatalyst was explored in Suzuki coupling reaction under green conditions, reduction of nitro compounds and the photodegradation of methyl orange with a degradation efficiency of 98.77%. The photodegradation of dyes is viewed as a potential method for the treatment of industrial wastewater due to its low cost, ecologically acceptable procedure, and lack of secondary contamination. Through direct photodegradation or a degradation process involving sensitization, this approach exhibits the light-enhanced creation of charge carriers and reactive radicals that non-selectively break down a variety of organic dyes into water, CO2, and other organic molecules. Moreover, Pd@NGO shows excellent stability and can be used multiple times, and hence possesses efficient reusability. [ABSTRACT FROM AUTHOR]

1,8‐Naphthalimides (NIs) represent a class of organic dyes with interesting optical properties that has been extensively explored in the last decades in lighting devices, chemosensors, optical probes or medicinal chemistry. However, despite their remarkable potential, reports on organometallic dyes bearing NIs are scarce and virtually inexistent regarding palladium(II) complexes. Herein, we report the synthesis of NIs bearing phosphine and amine chelating moieties and the characterization of their optical properties both as single molecules and when complexed on Pd(II) ions. It is shown that the introduction of phosphine moieties in the naphthalimide core results in a marked increase in non‐radiative processes, leading to a significant reduction of the emission efficiency and lifetime of these dyes, compared to amine‐bearing counterparts. The complexation to Pd(II) sequesters the electronic contribution of chelating moieties, with complexes assuming an optical behavior similar to that of unsubstituted 1,8‐naphthalimide. The complexation significantly increases the acidity of chelating secondary amines, giving rise to an unexpected intramolecular reaction that results in the formation of a novel 1,8‐naphthalimide dye bearing a cyclic phosphorylamide moiety. The new dye exhibits good emission quantum yield, long fluorescence lifetime and sensitivity to basic media, evidencing potential for application in optical imaging and sensing scenarios. [ABSTRACT FROM AUTHOR]

The removal of organic pollutants has become an increasingly important environmental concern. In recent years, there has been significant research into the use of nanomaterials for removing organic dyes in single-component systems. In this study, magnetic mesoporous silica nanoparticles (magnetic MSNs) were prepared with an average particle size of 170 nm. Iron oxide nanoparticles (20 nm) were embedded within the mesoporous silica structure. These nanoparticles were functionalized with amine, derivatized with thiol, and then reacted with 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB). The presence of DTNB molecules attached to the surface was confirmed by FTIR spectra, as evidenced by the appearance of peaks at ∼1528 cm−1 and ∼1365 cm−1. The nanoadsorbents demonstrated high removal efficiency for bromothymol blue (BT) and methyl orange (MO) at a pH below 5, with a maximum adsorption capacity of 139.27 mg/g and 101.62 mg/g for BT and MO, respectively. The linear regression coefficient value suggested that the adsorption of BT and MO onto magnetic MSNs-DTNB followed the Langmuir isotherm and second-order process. Overall, these findings suggest that magnetic MSNs-DTNB could be a promising nanoadsorbent for removing organic pollutants from contaminated water sources. [ABSTRACT FROM AUTHOR]

Results of studying features of spinel structure formation in the CoO–Fe2O3 system obtained using various production techniques are presented. The possibility of forming cobalt (II) ferrite at the surface of a number of carriers is considered. It is shown that depending upon structural characteristics of the substrate, the cobalt (II) ferrite formed has different dispersion and degree of reversibility. It is established that increased catalytic activity in the process of purification of an aqueous solution from an organic dye during hydrogen peroxide breakdown of synthesized materials with an organic carrier has been established. [ABSTRACT FROM AUTHOR]

Efficient and excellent nanoparticles are required for the degradation of organic dyes in photocatalysis. In this study, silver–manganese oxide nanoparticles (Ag-Mn-NPs) were synthesized through a wet chemical precipitation method and characterized as an advanced catalyst that has enhanced photocatalytic activity under sunlight irradiation. The nanoparticles were characterized using scanning electron microscopy (SEM), XRD, UV–vis light spectra, and energy-dispersive X-ray (EDX) spectroscopy, revealing their spherical and agglomerated form. The EDX spectra confirmed the composition of the nanoparticles, indicating their presence in oxide form. These bimetallic oxide nanoparticles were employed as photocatalysts for the degradation of malachite green (MG) dye under sunlight irradiation in an aqueous medium. The study investigated the effects of various parameters, such as irradiation time, catalyst dosage, recovered catalyst dosage, dye concentration, and pH, on the dye's photodegradation. The results showed that Ag-Mn oxide nanoparticles exhibited high photocatalytic activity, degrading 92% of the dye in 100 min. A longer irradiation time led to increased dye degradation. Moreover, a higher catalyst dosage resulted in a higher dye degradation percentage, with 91% degradation achieved using 0.0017 g of the photocatalyst in 60 min. Increasing the pH of the medium also enhanced the dye degradation, with 99% degradation achieved at pH 10 in 60 min. However, the photodegradation rate decreased with increasing dye concentration. The Ag-Mn oxide nanoparticles demonstrate excellent potential as a reliable visible-light-responsive photocatalyst for the efficient degradation of organic pollutants in wastewater treatment. [ABSTRACT FROM AUTHOR]

Composite heterogeneous catalysts of ferrous and manganese oxalate (FeC2O4/MnC2O4) were prepared via simple chemical co-precipitation. The catalytic performance was evaluated by determining the degradation efficiency of rhodamine B (RhB). Under optimum conditions, 6-1FeMn showed the best catalytic performance, and the degradation efficiency exceeded 95 % within 2 min, which was 1.4 times more than ferrous oxalate. Under a wide pH range (1–8), 6-1FeMn showed high degradation efficiency for RhB with good recyclability and reusability. By characterizing the catalysts before and after the reaction and analyzing the degradation process, a possible mechanism was proposed: Mn2+ and Fe2+ synergistically catalyzed and produced a large number of hydroxyl radicals (·OH) by forming a composite active site for efficient reactivation. Mn3+ accelerated the transfer between Fe2+ and Fe3+. In addition, C2O42− reactivated the active site in situ and enhanced the catalytic properties. This study provides new insight into the catalytic degradation of organic dyes using composite heterogeneous Fenton catalysts. [ABSTRACT FROM AUTHOR]

Remediation of organic dyes from wastewater in textile industries is a big challenge to decreasing water pollution. This study was aimed at the preparation of ZnO nanoparticles (NPs) and their application as a photocatalyst for the degradation of methylene blue (MB), sunfix red (SR) and real textile wastewater (RTW) under both UV and visible irradiations. The ZnO NPs were synthesized with a green Thymus vulgaris leaf extract-supported approach following the calcination process. 50 mg L−1 MB and 50 mg L−1 SR dyes were completely photodegrade under UV irradiation after only 20 and 45 minutes, respectively, in the presence of 1.0 mg/mL ZnO NPs. When they are exposed to visible light, the degradation efficiency reached 91 and 75% within 60 and 120 min, respectively. Photocatalytic measurements of RTW depict that 95% (within 60 min under UV illumination) and 79% (within 90 min under visible illumination) were degraded, respectively. The enhanced photodegradation can be attributed to the narrowing of the bandgap of the ZnO NPs, high crystallinity and nearly hexagonal morphology with an average size of 20–30 nm. The present results show that ZnO NPs could potentially be applied for high-efficiency degradation of organic dyes and RTW under both UV and visible light irradiation. We report for the first time, Thymus vulgaris leaf extract–assisted synthesis of ZnO nanoparticles (NPs) has been applied as a photocatalytic dye and RTW degradation. Second, our synthesis approach is more facile and simple than the previous method where complex hydrothermal or solvothermal methods have been applied, which leads to a complex preparation procedure. We systematically prepared ZnO materials in taking account into the variable Thymus vulgaris/ZnO precursor ratio, different calcination temperature and time and in detail, their photocatalytic activity has been fully investigated. [ABSTRACT FROM AUTHOR]

The functionalized NiFe‐LDH with photosensitized GQDs were synthesized through the hydrothermal route by differing the amount of GQDs solution and studied its efficacy towards the mineralization of textile dyes under visible light. The synthesized samples were characterized by XRD, FESEM, HRTEM, DRUV‐Vis, RAMAN, XPS, and BET. The combined effect of the hexagonal carbon lattice in GQD and open layered porous structure of NiFe‐LDH nanosheets results in the contraction of the lattice. Different reactive and conventional dyes were taken as representative dyes to evaluate the activity of the as‐synthesized photocatalysts. The enhanced electron absorption/donor effect between GQDs and NiFe‐LDH, and the growth of oxygen‐bridged Ni/Fe−C moieties enable the composite to exhibit better photocatalytic activity. Both photocatalytic activity and characterization results confirmed that the GQD@NiFe‐LDH nanocomposite heterostructure synthesized at 160 °C by taking 10 mL of GQDs aqueous solution named GNFLDH10 has a higher degree of crystallinity and has the best photocatalytic efficiency compared to other reported visible light catalysts. Specifically, the above optimized GQD@NiFe‐LDH photocatalyst is capable of photo‐mineralizing 50 ppm of Reactive Green in 20 min, Reactive Red in 20 min, and Congo Red in 25 min respectively following a direct Z‐scheme mechanism with substantial reusability. [ABSTRACT FROM AUTHOR]

This study proposes a new method for producing α-Fe2O3–CuO nanocatalyst that is both cost-effective and ecologically benign. The α-Fe2O3–CuO nanocomposite was prepared via moderate thermal oxidative decomposition of copper hexacyanoferrate. Its structure and surface morphology are affirmed via XRD, SEM, FTIR, EDX, TEM, XPS, and VSM. In the presence of H2O2, α-Fe2O3–CuO is employed as a heterogeneous catalyst to stimulate thermally induced degradation of dyes such as direct violet 4, rhodamine b, and methylene blue. The synergistic effect of Fe2O3 and CuO enhanced the catalytic activity of the nanocomposite compared to Fe2O3 and CuO separately. The effectiveness of DV4 degradation is optimized by evaluating multiple reaction parameters. The reaction rate increased substantially with the temperature, revealing its key role in the degradation process. Higher H2O2 levels and the inclusion of inorganic anions like chloride or nitrate also sped up the degradation process. While sulfate and humic acid, particularly at high doses, slowed it. The mechanism of H2O2 activation on α-Fe2O3–CuO is studied. The measurements of chemical oxygen demand and total organic carbon indicate that all dyes are highly mineralized. The remarkable performance and stability of this nanocomposite in removing diverse dyes render it a promising option for wastewater remedy. [ABSTRACT FROM AUTHOR]

Present study reports the hydrothermal synthesis procedure to prepare the facile and sustainable orthorhombic Molybdenum trioxide (α-MoO3) nanoparticles (NPs) for the degradation of thymol blue dye. Synthesized α-MoO3NPs was characterized by FTIR, XRD, Zeta-potential, SEM, and TEM to investigate the functionalities, texture, size, and morphology of α-MoO3 NPs. The average size was calculated up to 68 ± 5 nm. The α-MoO3NPs was successfully applied to degrade toxic organic dye (thymol blue) in aqueous media. To achieve maximum percentage degredation of dye different parameters were optimized, including a catalyst dose, reaction time, effect of microwave irradiation at low power, reproducibility of catalyst. At optimum conditions, the fabricated α-MoO3NPs-based heterogeneous nano-catalyst was highly efficient for degrading thymol blue dye in aqueous media; the percentage degradation was obtained up to 99% within 60 s just using 120 µg of α-MoO3NPs was used under the microwave radiations. The heterogeneous nano-catalyst shows excellent performance and is highly efficient as compared to previously reported work. The schematic diagram for the degradation of thymol blue dye using prepared MoO3 nano-catalyst [ABSTRACT FROM AUTHOR]

This paper proposes a simple and environmentally friendly method for the green synthesis of SnO2–ZnO/bentonite nanocomposite in the presence of Acroptilon repens flower extract as a reducing and stabilizing agent. The synthesized nanocomposite was characterized using various techniques to investigate their structural properties and morphology. The photocatalytic degradation of the organic dye, eriochrome black-T (EBT) under solar irradiation and in the presence of synthesized nanocomposite was investigated. The results indicated that the nanoparticles were well immobilized onto bentonite as a support with minimum agglomeration. Moreover, the results of photocatalytic reactions showed that SnO2–ZnO/bentonite nanocomposite could remove the dyes in just 2.5 h and the degradation efficiencies approached 100% indicating the excellent performance of the catalyst. The kinetic study revealed that degradation of EBT in presence of the SnO2–ZnO/bentonite nanocomposite obeys first-order kinetics with the rate constant of 1.75 × 10–2 min−1. Furthermore, the biosynthesized nanocomposite exhibited a stable performance and high tolerance to the reaction conditions and was reused in three cycles with negligible loss of activity. [ABSTRACT FROM AUTHOR]

Metal ion doping is the most widely used means to improve the photocatalytic performance of semiconductor materials, which can adjust the band gap, broaden the range of optical response and construct impurity levels. The high efficiency modified NaTaO3 perovskite catalyst with good structural and catalytic properties was synthesized by a simple hydrothermal reaction method. A variety of analysis and testing techniques, such as XRD, SEM, DRS, XPS and EPR, were used to analyze the structure properties of the prepared materials. The results show that the influence mechanism of different metal introduction on the structure and properties of the NaTaO3 perovskite was different. Metal doping promoted the bond angle of Ta-O-Ta close to 180°, which restrains the recombination of the photogenerated electron-holes in the crystal. As Ce is introduced into the perovskite, the CeO2 forms and agglomerates around the perovskite, which improves the electron transport performance. With the narrower band gap, the Ce-modified perovskite shows that the degradation rate of ARS is 84% after 180 min of photoreaction. The species of h+, O2− and ·OH play different roles in improving the performance of the photocatalytic degradation process. [ABSTRACT FROM AUTHOR]

[Display omitted] A nanocomposite based on graphene oxide and cobalt trimesinate was obtained by in situ method and employed in solid-phase extraction of organic pollutants using the triphenylmethane dye, brilliant green, as an example. The maximum adsorption reaches 385.2 mg g–1. [ABSTRACT FROM AUTHOR]

[Display omitted] The development of highly efficient piezocatalysts has attracted widespread attention for energy conversion and pollution abatement. This paper reports for the first time exceptional piezocatalytic properties of a Zn- and N -codoped porous carbon piezocatalyst (Zn-N x -C) derived from the zeolitic imidazolium framework-8 (ZIF-8) for both hydrogen production and degradation of organic dyes. The Zn-N x -C catalyst has a high specific surface area of 810.6 m2/g and retains the dodecahedron structure of ZIF-8. Under ultrasonic vibration, the hydrogen production rate of Zn-N x -C has achieved 6.29 mmol/g/h, surpassing most recently reported piezocatalysts. Additionally, the Zn-N x -C catalyst demonstrates a 94% degradation efficiency for organic rhodamine B (RhB) dye during 180 min of ultrasonic vibration. This work sheds new light on the potential of ZIF-based materials in the field of piezocatalysis and provides a promising avenue for future developments in the area. [ABSTRACT FROM AUTHOR]

In this study, proanthocyanidins-functionalized Fe3O4 magnetic nanocomposites were synthesized by the hydrothermal method. The prepared Fe3O4 nanocomposites were characterized by Fourier transform infrared spectrometer (FTIR), X-ray powder diffractometer (XRD), physical property measurement system (PPMS), particle size analyzer, scanning electron microscope (SEM), and transmission electron microscope (TEM). FTIR results indicated that the obtained products were coated with proanthocyanidins. The SEM and TEM results, as well as particle size distribution analysis, revealed that the obtained products were spherical particles with average diameter of 3 2 8. 6 2 ± 2 6. 7 5 nm. XRD and PPMS characterization confirmed that the Fe3O4 nanoparticles have a cubic spinel structure with magnetic properties. The performance of the Fe3O4 nanocomposites for removing organic dyes in an aqueous solution was investigated. The synthesized products were found to be effective on removing various organic dyes, such as Methylene blue (MB), neutral red (NR) and Rhodamine B (RhB), indicating their considerable potential as efficient dyes adsorbents for wastewater treatment. Proanthocyanidins-functionalized Fe3O4 magnetic nanocomposites were synthesized by the hydrothermal method. The obtained Fe3O4 nanocomposites can efficiently remove the organic dyes in an aqueous solution. Proanthocyanidins-functionalized Fe3O4 magnetic nanocomposites had the potential to be developed as efficient dyes adsorbents for wastewater treatment. [ABSTRACT FROM AUTHOR]

Wastewater remediation is a major issue that threatens the ecosystem and health of human population and hence deserves our undivided attention. Dye effluents, in particular those comprising organic colourants from a number of industrial sites, are a major source of wastewater pollution that poses serious dangers to human health and the environment today. Therefore, the goal of this study is to eliminate these coloured effluents, which are present in substantial amounts in wastewater, either singly or in mixtures. In this respect, we present an easy sol-gel synthesis of CoFe 2- x Cr x O 4 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) nano-ferrites for use as efficient photocatalysts. P-XRD technique was used for the confirmation of cubic spinel nanostructures having crystallite sizes in the nano-regime. Also, the optical band gap values resulted from Tauc plot indicates that incorporation of Cr3+ significantly reduces the band gap values. All the Co–Cr nano photocatalysts can be easily separable using an external magnet as indicated by the magnetic studies. For exploring the photocatalytic activity by photo-fenton process, we chose Rhodamine-B (RhB) as a model dye pollutant. Surprisingly, Cr3+ substitution into cobalt ferrite resulted in a dramatic transformation of the inert CoFe 2 O 4 into a highly visible light active photocatalyst for organic pollutant degradation. The CoFeCrO 4 nanocatalyst showed excellent results for the removal of RhB i.e., 99% removal in 30 min as compared to the CoFe 2 O 4 which was found to be inactive for the degradation. As a result of these exciting photocatalytic results, we were further encouraged to extend the degradation of a few other organic dye contaminants such methylene blue (MB), methyl orange (MO) and the mixture all three dyes (RhB + MB + MO). It was found that CoFeCrO 4 photocatalyst efficiently and swiftly degrades all three dye contaminants individually or in mixture with excellent recyclability and durability. [ABSTRACT FROM AUTHOR]

Advance the photo-activity of the nano-sized ZnO photocatalyst is an essential factor in remediation of environmental pollution caused by industrial-organic dyes. Blends of transition elements including Mn, Fe and Co ions were employed to modify the energy gap and the visible absorption state tail of ZnO as well as inhibit the charge carriers recombination by their flexible oxidation states. Five nanocatalysts composed of ZnO, Zn0.97Mn0.015Fe0.015O, Zn0.97Mn0.015Co0.015O, Zn0.97Fe0.015Co0.015O and Zn0.97Mn0.01Fe0.01Co0.01O were simply synthesized. All the prepared compositions have a single phase of ZnO wurtzite structure. Both compositions of Zn0.97Fe0.015Co0.015O and Zn0.97Mn0.01Fe0.01Co0.01O have high sensitive responses to visible light spectrum owing to band gap reduction and formation of absorption state tails. The SEM images demonstrated that the kind of the transition metal blends added to ZnO powder have a significant effect on its morphology. Remarkably, the addition of (Fe, Co) mixture to ZnO powder leads to formation of homogenous rods structure besides very fine spherical particles. All modified ZnO samples revealed enhanced photocatalytic activity but Zn0.97Fe0.015Co0.015O powder possesses the greatest efficiency (98%) for 25 ppm Reactive Yellow 145 dye in 75 min of solar illumination with acceptable stability. In addition, Zn0.97Fe0.015Co0.015O catalyst revealed high photo-removal activity for 25 ppm Rhodamine B and malachite green with measured efficiencies of 94 and 91% in 75 min, respectively. The suitable catalyst dose was identified to be 0.04 g (100 mL solution) and the main effective radicals are the hydroxyl (·OH) species. [ABSTRACT FROM AUTHOR]

The photocatalytic, sonocatalytic, and sono‐photocatalytic performances of Ba0.5Sr0.5TiO3 (BST) ceramic (synthesized through solid‐state reaction route) were investigated for the degradation of an organic dye named methylene blue (MB). The as‐prepared BST ceramic powder was characterized using a scanning electron microscope, X‐ray diffraction, X‐ray photoelectron, and Raman spectroscopy techniques. The optical energy band gap of BST ceramic was found to be ∼3.17 eV. BST has shown significant catalytic activity following sonocatalysis and photocatalysis processes, i.e, ∼48% and ∼65% in 3 h, respectively. The synergic effect of the sonocatalysis and photocatalysis processes had shown an excellent degradation of 81% in 3 h. To determine the reactive species responsible for the degradation of MB dye, a scavenger test was also performed using isopropyl alcohol (IPA), ethylenediaminetetraacetic acid (EDTA), and benzoquinone (BQ) scavengers. The degree of MB dye degradation was quantified by a phytotoxicity test on "Vigna radiata" seeds. Furthermore, the potentiality of BST ceramic was explored for water cleaning applications while irradiating it to solar radiation in real‐time conditions. [ABSTRACT FROM AUTHOR]

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