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A new amphiphilic azo‐functionalized polyhedral oligomeric silsesquioxane (POSS) derivative was synthesized by functionalizing octa(3‐aminopropyl)silsesquioxane (OAS‐POSS) with 4‐((4‐(dodecyloxy)phenyl)diazenyl)benzoic acid, affording a hydrophilic amino POSS head and hydrophobic dodecyl tail with a diphenyl‐azo connector. Prepared amphiphilic azo‐functionalized POSS (azo‐POSS) exhibited high ability for encapsulation and transferring cationic dyes into the organic phase by vigorously mixing with aqueous solutions of each dye. The photo‐controlled encapsulating properties of the synthesized phase transfer reagent was studied using cationic dyes, such as methylene blue (MB), crystal violet (CV) and thymol blue in acidic conditions. Results showed more than 95 % encapsulation of MB. However, no considerable encapsulation was shown in the case of anionic dyes such as eriochrome black T (EBT) and thymol blue in alkaline solutions. By trans/cis isomerization of the azo moiety of the phase transfer reagent by UV irradiation (365 nm), the amount of dye encapsulation was decreased, which could be attributed to the formation of cis isomer that led to the folding of the dodecyl alkyl tail on the POSS moiety, and therefore prevent to lay the 3‐aminopropyl moieties of POSS head to the water/DCM interface to adsorb and encapsulate MB molecules. [ABSTRACT FROM AUTHOR]

Tribocatalysis is one of the emerging processes for organic dye degradation application. The process uses mechanical energy as a source for breaking down organic pollutants present in water. The synergistic effect of two catalysis processes for eliminating organic pollutants, here in the present study photocatalysis an advanced oxidation process is integrated with the tribocatalysis process for enhancing the degradation efficiency of the tribocatalysis process by using BaTiO3 ceramic powder as a catalyst. The responsible factors for dye degradation via the tribocatalysis process such as surface roughness of the materials utilized, force applied, and energy band gap of the catalyst are also studied. The Methylene Blue dye's degradation was ~39%, ~60%, and ~76% through tribocatalysis, photocatalysis, and photo-tribocatalysis respectively by using 400 mg BaTiO3 ceramic powder in 8 h. The synergistic effect of photocatalysis and tribocatalysis process showed enhanced degradation compared to individual processes. [ABSTRACT FROM AUTHOR]

Aerogels present a huge potential for removing organic dyes from printing and dyeing wastewater (PDW). However, the preparation of aerogels with multiple dye adsorption capabilities remains a challenge, as many existing aerogels are limited to adsorbing only a single type of dye. Herein, a composite aerogel (CG/T‐rGO) with the addition of carboxymethyl chitosan, gelatin and tannic acid reduced graphene oxide (T‐rGO) was synthesized by freeze‐drying technology. The electrostatic interactions between dye molecular and GEL/CMCS (CG) networks, as well as the supramolecular interactions (H‐bonds, electrostatic interactions and π–π stacks) between T‐rGO, have endowed the aerogel with the ability to adsorb multiple types of dye, such as methylene blue (MB) and methyl orange (MO). Results exhibited that the prepared CG/T‐rGO aerogel possessed strong mechanical strength and a porous 3D network structure with a porosity of 96.33 %. Using MB and MO as adsorbates, the adsorption capacity (88.2 mg/g and 66.6 mg/g, respectively) and the mechanism of the CG/T‐rGO aerogel were investigated. The adsorption processes of aerogel for MB and MO were shown to follow the pseudo‐second‐order kinetic model and Langmuir isotherm model, indicating the chemical adsorption of a monolayer. The proposed aerogel in this work has promising prospects for dye removal from PDW. [ABSTRACT FROM AUTHOR]

Advanced oxidation process using reactive oxygen species (ROS) can be efficiently utilized to remove soluble contaminants from water. Herein, we have reported a facile method for the activation of molecular oxygen to produce ROS using Prussian blue analog (PBA)‐derived catalyst CoNx@NC. The two‐electron reduction of O2 by CoNx@NC produces H2O2, which is further dissociated into ⋅OH radicals and decomposes water‐soluble organic dye (methylene blue) and antibiotics (ciprofloxacin and amoxicillin). CoNx@NC is capable of removing 98 % of ciprofloxacin in a short period of time (65 minutes) in the presence of oxygen. Further, CoNx@NC can activate peroxodisulfate in the aqueous medium to produce ROS (SO4⋅−, and ⋅OH) and catalyzes the decomposition of the antibiotics and organic dye. The efficiency of the degradation of antibiotics and dye is improved when peroxodisulfate is used for the formation ROS. The higher oxidation potential and longer life‐time of SO4⋅− than ⋅OH improves the rate oxidation with peroxodisulfate. The Co−N coordination in CoNx@NC stabilizes the system against leaching and shows excellent stability for recycling (for five cycles) during the removal of contaminants. [ABSTRACT FROM AUTHOR]

Organic dye molecules and pathogenic microorganisms exist widely in printing and dyeing wastewater, causing persisting concerns about water environment safety. Herein, newly developed alginate–chitosan–graphene oxide nanosheets gel beads with both exceptional adsorption and antibacterial functions are reported. NaHCO3 is selected as porogen and Ag+ is used as antibacterial enhancer. The adsorption properties of the beads fit well with the Langmuir isotherm and pseudo‐second‐order model, suggesting a monolayer behavior of the adsorption and their reaction rate is controlled by chemisorption. The theoretical liminal value of the adsorption of methylene blue by the beads reaches 847.46 mg g−1. After five adsorption–desorption cycles, the beads retain almost intact adsorption activity, and the sterilization rates of Escherichia coli and Staphylococcus aureus remain at 99.99%. The results give insight into developing new processing routes for constructing gel beads for versatile applications. [ABSTRACT FROM AUTHOR]

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

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

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]

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]

Two‐dimensional MXenes are excellent photocatalysts. However, their low oxidation stability makes controlling photocatalytic processes challenging. For the first time, this work elucidates the influence of the oxidation stabilization of model 2D Ti3C2Tx MXene on its optical and photocatalytic properties. The delaminated MXene is synthesized via two well‐established approaches: hydrofluoric acid/tetramethylammonium hydroxide (TMAOH‐MXene) and minimum intensive layer delamination with hydrochloric acid/lithium fluoride (MILD‐MXene) and then stabilized by L‐ascorbic acid. Both MXenes at a minimal concentration of 32 mg L−1 show almost 100% effectiveness in the 180‐min photocatalytic decomposition of 25 mg L−1 model methylene blue and bromocresol green dyes. Industrial viability is achieved by decomposing a commercial textile dye having 100 times higher concentration than that of model dyes. In such conditions, MILD‐MXene is the most efficient due to less wide optical band gap than TMAOH‐MXene. The MILD‐MXene required only few seconds of UV light, simulated white light, or 500 nm (cyan) light irradiation to fully decompose the dye. The photocatalytic mechanism of action is associated with the interplay between surface dye adsorption and the reactive oxygen species generated by MXene under light irradiation. Importantly, both MXenes are successfully reused and retained approximately 70% of their activity. [ABSTRACT FROM AUTHOR]

The synthesis of inorganic nanoparticles via a green method has obtained a vast attention because of its simplicity, eco‐friendliness, less toxicity and cost‐effectiveness. In this present study, silver nanoparticle has been synthesized via the mixture of tea leaf and aloe vera leaf extract at room temperature. The synthesized silver nanoparticle was characterized in detail. Dynamic Light Scattering analysis shows an average particle size of 90 nm. The polyphenolic compounds present in the tea and aloe vera leaves act as the capping agent for the growth of synthesized nanoparticles. The isolated silver nanoparticles possess remarkable catalytic activity towards the degradation of organic dyes including methylene blue, methyl orange and rhodamine B. The catalyst also shows good cyclability for dye degradation along with chemical and structural stability. The present study suggests that silver nanoparticles synthesized by tea and aloe vera extract could be a potential stable catalyst for the degradation of various kinds of dyes and these types of plant extracts can be used to prepare efficient catalysts for various kinds of applications. [ABSTRACT FROM AUTHOR]

The preparation of Cobalt ferrite‐Ocimum sanctum nanocomposite, referred to as CoFe2O4/OS, has been reported along with its application for the treatment of water containing hazardous organic contaminants. A simple co‐precipitation approach was applied for synthesis of magnetic nanocomposite, and a thorough analysis for its characterization was conducted using several spectroscopic and microscopic techniques. The characterization results showed that the magnetic nanocomposite exhibited substantial functional groups of Ocimum sanctum powder and magnetic ferrite part. The adsorption investigation of nanocomposite for removal of two cationic dyes was carried out with varying parameters, such as pH, contact time, temperature, concentration, and composite dosage. The sorption process was proved feasible and exothermic at the tested temperatures (303–323 K). The sorption data followed Freundlich and Temkin isotherms which recommended the physisorption progression. The kinetic study revealed a pseudo‐second order rate of sorption process for both dye molecules. The facile preparation, economical cost, significant magnetic character, and high sorption capacity will surely construct the water treatment system more competent with the use of CoFe2O4/OS. [ABSTRACT FROM AUTHOR]

Organic dyes, present in the aquatic environment, have negative effects on ecosystems. Attempts are being made to remove these dyes by using number of physico‐chemical methods. Out of all the methods, adsorption technique is the most economical and efficient technique. However, for this purpose, efficient and cost‐effective adsorbents are needed. In this paper processed neem leaf powder (NLP) has been used for methylene blue (MB) dye removal. NLP has been characterized by X‐ray diffraction, FTIR spectroscopic, and scanning electron microscopic techniques. Results have shown that NLP has crystalline character with number of functional groups. MB is removed by using NLP under different varying conditions such as NLP doses, varying MB concentration, and different pH. When fixed amount of NLP (0.2 g) is used, removal of MB increases with time and becomes almost constant after 40 min. Maximum MB removal is obtained at pH = 6.0. Adsorption isotherms and kinetic models are discussed and the data fitted well with Langmuir isotherm and pseudo second order kinetic models. Ab initio calculations have shown that nature of interaction depends on the orientation of groups and both type of adsorption is feasible in the present system. Results show that NLP is an effective adsorbent for removal of MB dye. [ABSTRACT FROM AUTHOR]

Organic dyes, present in the aquatic environment, have negative effects on ecosystems. Attempts are being made to remove these dyes by using number of physio‐chemical methods. Out of all the methods, adsorption technique is the most economical and efficient technique. For this purpose, efficient and cost‐effective adsorbents are needed. Neem leaf powder (NLP) containing Azadirachtin Indica, has been used for methylene blue (MB) dye removal. The interaction of dye on neem leaf containing Azadirachta indica plays an important role. Quantum mechanical calculations using density functional theory have been done in order to have an idea about interaction during adsorption. There is a possibility of both strong and weak interaction depending on the orientation of adsorbent and adsorbate. [ABSTRACT FROM AUTHOR]

Environmental contamination due to organic pollutants including organic dyes (e. g. methylene blue (MB)) and paraquat (i. e. methyl viologen (MV)) has become a serious problem. Herein, the removal for toxic cations of methylene blue (MB+) and methyl viologen (MV2+) has been realized by a three‐dimensional (3D) anionic microporous metal‐organic framework, namely [Me2NH2][In(TDC)2] ⋅ 1.5DMA ⋅ H2O (FJSM‐InMOF). FJSM‐InMOF is capable of selectively adsorbing MB+ in the presence of various dyes due to the effects of size‐exclusion and charge‐matching. Particularly, the strategy of combining adsorption and photocatalytic degradation realizes the thorough treatment of MB+, which has been rarely reported. The adsorbent material can be easily regenerated and reused. Moreover, FJSM‐InMOF exhibits a high capacity and rapid kinetics towards more toxic MV2+. This work poses a new way for the selective removal of cationic organic pollutants and highlights the significance of combining different methods for the decontamination of organic pollutants. [ABSTRACT FROM AUTHOR]

The CeCoO3/MoS2 heterojunction was successfully prepared through the hydrothermal method. The synthesized heterojunction structure was characterized by various techniques and applied to the conversion of methylene blue (MB) under irradiation of visible light. To characterize the new heterojunction structure, Fourier transformed infrared (FT‐IR), field emission scanning electron microscope (FE‐SEM), energy‐dispersive X‐ray spectroscopy (EDXS), X‐ray diffraction (XRD), photoluminescence spectroscopy (PL), differential reflectance spectroscopy (DRS), and transmission electron microscopy (TEM) analyses were used. The FE‐SEM images illustrated the successful deposition of MoS2 flower‐like on the surface of CeCoO3 perovskite with 46 nm as an average size. The influence of the amount of catalyst, temperature, pH, and electron acceptor were investigated. By CeCoO3/MoS2 heterostructures photocatalyst, the conversion rate of MB reached 98% within 20 min, whereas by CeCoO3 perovskite no significant conversion was observed in MB. The higher photocatalytic performance of CeCoO3/MoS2 heterostructures is assigned to their lower charge recombination compared to CeCoO3 perovskite. Moreover, the photocatalytic mechanism and recycling experiments of CeCoO3/MoS2 heterostructures are discussed in detail. The CeCoO3/MoS2 heterostructures are thus promising photocatalysts for the cleanup of polluted water. [ABSTRACT FROM AUTHOR]

Modeling and simulation of batch adsorption of the organic dye methylene blue (MB) by modified metal‐organic framework‐5 (MOF‐5) were investigated. The reported data on the adsorption of MB dye onto Wells‐Dawson acids (H6P2W18O62)‐immobilized MOF‐5 were employed. The film‐pore diffusion model was developed based on external mass transfer coefficient and pore diffusion coefficient that govern the mass transfer process in batch organic dye adsorption. Applying the estimated parameters, the MB adsorption by using modified MOF‐5 was examined to evaluate the effects of MOF‐5 modification, initial dye concentration, temperature, and the dosage of adsorbent. The adsorption capacity of modified MOF‐5 (H6P2W18O62/MOF‐5) was higher than pure MOF‐5. Besides, a lower initial MB dye concentration, higher temperature, and lower adsorbent dosage resulted in higher MB dye adsorption capacity. [ABSTRACT FROM AUTHOR]

A copper‐based metal‐organic framework (MOF) Bis[5‐(2‐pyridyl)tetrazolato]diaquacopper(II) [{CuP}n], has been designed and structurally characterized by single‐crystal X‐ray crystallography. The three‐dimensional crystal structure belongs to the monoclinic space group P21/c with Z=4. Further a series of isostructural complexes [{Cu1‐xZnxP}n] (x=1, 0.75, 0.5, 0.25, 0), {P=(5‐(2‐pyridyl)tetrazolato)2.2H2O} have been synthesized via a facile one‐pot microwave irradiated solvothermal method. The optical and photocatalytic properties of the synthesized bimetallic complexes were investigated and compared with those of monometallic complexes. The effects of metal substitutions in the ligand backbone were investigated. A striking variation in the bandgap i. e. from 4.1 eV (x=1) to 2.79 eV (x=0) was observed among the catalysts with a minimum value of 1.93 eV (x=0.25). The optimized catalyst Cu0.75Zn0.25P exhibits the highest degradation activity and reached up to 99 % for RhB (rhodamine B) and 96 % for MB (methylene blue) in 120 min of Sunlight, corresponding to the respective photocatalytic degradation rates of 0.0328 min−1 and 0.0301 min−1. The kinetics of the degradation processes were best statistically described by pseudo‐first‐order. The catalyst was also found to have sufficient stability and recyclability with promising applications in removal of organic dye pollutants. [ABSTRACT FROM AUTHOR]

A MOF named [(CH3)NH2] [H2N(CH3)2][ZnTNC4A] ⋅ 4H2O (ZnTNC4A) was synthesized by a resorcinol[4]arene functionalized tetracarboxylic acid ligand (TNC4A=2,8,14,20‐tetra‐1‐naphthalene‐6,12,18,24‐tetramethoxy‐4,10,16,22‐ tetracarboxyl‐methoxy‐resorin[4]arene). The three‐dimensional framework with one‐dimensional channels of ZnTNC4A was characterized by elemental analysis, powder X‐ray diffraction, thermogravimetry, UV‐vis diffuse reflection spectrum, infrared spectrum and N2 adsorption analyse. In addition, ZnTNC4A shows the ability of selective adsorption of methylene blue with a pseudo‐second order kinetic model. The selective adsorption kinetics of a series of dyes showed that the ion exchanged separation process was related to the size and charge of organic dyes. [ABSTRACT FROM AUTHOR]

Copper silicate (CS) bound to a nonwoven textile was prepared using a very simple procedure employing water glass as a precursor and subsequent copper sulfate treatment. Peroxidase‐like activity of the textile‐based CS derivative was detected for the first time. This new nanozyme was employed for the decolorization of three model organic dyes: Bismarck brown Y, Congo red, and methylene blue. Both adsorption and peroxidase‐like dye degradation were involved during the decolorization process. [ABSTRACT FROM AUTHOR]

Wastewater treatment has become a research hot issue in recent decade. Organic dyes as one of the main pollutants can change the water behavior. To deracinate the organic pollutants from wastewater, there are numerous methods have been taken into consideration. Photocatalysis is the promising strategy for the dye degradation with low cost, high efficiency, and environmental friendliness. Hence, a novel one‐dimensional (1D) magnetic Bi2Fe4O9/C@AgBr composite photocatalyst was prepared employing electrospinning, calcination, and deposition–precipitation methods. The morphology and composition of photocatalyst were characterized, as well as the photocatalytic activities of degrading methylene blue (MB) under visible light were investigated. And the results exhibited that the efficiency of Bi2Fe4O9/C@AgBr under visible light for 60 min is 97.4%. After three cycles, the degradation efficiency of MB could still reach 88.0%. Moreover, radical quenching experiment implicated superoxide radical anions as the primary active species responsible for photodegradation of MB. This work provides a new insight into the design of effective photocatalysts for practical application. [ABSTRACT FROM AUTHOR]

In this work, graphene was synthesized from waste discharged battery electrodes using an electrochemical exfoliation method. The graphene product was characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy and adsorption activity. For application, as‐synthesized graphene was used for preparation of Fe3O4/graphene/chitosan (FGC) nanocomposite as a recyclable‐nanosorbent for removal of organic dyes including methylene blue (MB), methyl orange (MO), brilliant blue FCF (E133), eriochorome black T (EBT) and thymol blue (ThB) from aqueous solution. The obtained results shown that the FGC adsorbent is more attractive to MB and EBT than other evaluated dyes. At optimized conditions, FGC can adsorb MB at maximum adsorption capacity (qmax) of 94.16 mg g−1 and the remaining adsorption efficiency for the 5th cycle was 74.81 % compared to that of the pristine FGC nanosorbent. Moreover, the FGC nanocomposite was also used to remove MB from real wastewater with high removal efficiency. This performance implies a high application potential of synthesized graphene from waste graphite for environmental treatments. [ABSTRACT FROM AUTHOR]

A water‐insoluble Keggin‐type polyoxomolybdovanadate nanocluster, (Et4N)4[VMo12O40]·MeCN (1) was synthesized and crystallized in acetonitrile. The catalyst was characterized by X‐ray crystallography, UV–Vis, thermogravimetric analysis (TGA), cyclic voltammetry (CV), and FT‐IR techniques. Degradation of organic dyes, Amido black 10B (AB10B) and Methylene blue (MB) was investigated by 1/H2O2 system at room temperature and the influence of different conditions on the decomposition of AB10B and MB dyes such as catalyst dosage, oxidant concentration, pH, radical scavengers, and reusability of 1 were studied. [ABSTRACT FROM AUTHOR]

Tetragonal zirconia (t‐ZrO2) nanoparticles (NPs) were successfully synthesized by a green method using β‐cyclodextrin as stabilizer. The structural characterization of the prepared nanoparticles was done by X‐ray diffraction (XRD).The tetragonal crystalline structure of ZrO2 NPs was confirmed by XRD analysis. We employed the Rietveld method to refine the XRD data and the refinement result leads to specify the tetragonal phase of ZrO2 NPs with space group P 42/n m c. The FTIR spectrum gives the information about the presence of Zr−O bonding at 501 cm−1. Particle size and morphological properties were demonstrated by Scanning Electron Microscope (SEM) and elemental compositions were analysed using EDAX spectrum. The band gap energy was estimated using optical absorption spectroscopy and the value was found to be 3.99 eV. The UV (310 nm) and visible (401, 420 and 560 nm) emissions were observed from PL spectrum. Brunauer‐Emmet‐Teller (BET) surface analysis was used for determining the surface area and average pore size of ZrO2 NPs.The photocatalytic degradation of the prepared ZrO2 NPs for organic dyes had been studied under visible light irradiation. Results showed that 68 % degradation was achieved within 135 min for Methylene Blue (MB) dye but other dyes almost remains unchanged during the same reaction times. [ABSTRACT FROM AUTHOR]

The intelligent design or development of dual‐functional catalysts using non‐precious metals especially for the oxygen evolution reaction (OER) in sustainable energy systems and degradation of organic pollutants is still a difficult and a significant challenge. Furthermore, the development of these catalysts is of great importance in terms of energy security and solution of the environmental problems. To meet these requirements, herein, we describe the synthesis of a Ni‐ion doped Birnessite@Cryptomelane (Ni2+/B@Cr) hybrid structure as a bifunctional efficient catalyst for the OER in neutral media and degradation of dye pollutants. The Ni2+/B@Cr catalyst exhibited a sharp onset potential at 390 mV (vs. RHE) and achieved a current density of 1 mA cm−2 at a low ƞ of 430 mV with a Tafel slope of ~96 mV dec−1. The results of electrochemical impedance spectroscopy (EIS) studies indicated that Ni intercalation into birnessite layer and heterostructure of the hybrid electrocatalyst Ni2+/B@Cr increased the conductivity by lowering the resistance of charge transfer (Rct = 4.82 Ω) and oxygen evolution processes (ROER = 4.13 Ω). The durability assay identified Ni2+/B@Cr as stable electrocatalyst with 10% loss of activity after long‐term stability tests (10 h, under 500‐mV overpotential). In addition, the Ni2+/B@Cr achieved high (86.67 s−1 g−1) and rapid (173 s) catalytic performance for the reduction of methylene blue (MB). Overall, this paper presents a low‐cost production strategy for the design of highly efficient bifunctional catalysts, offering boosted electrocatalytic and degradation performance for water oxidation and organic dye contamination, respectively. [ABSTRACT FROM AUTHOR]

Cold‐chain management is of high importance in preserving perishable products and in retaining quality. A visible marker on packages indicating complete maintenance of the cold chain assures safe consumption of products by end‐users and assists in reducing waste. Time‐temperature indicators (TTIs) are integrated markers that provide information about exposure of packages to adverse temperature and have been gaining increased attention by consumers. Here we present a methylene‐blue‐based derivative, N,N,N′,N′‐tetramethyl‐N10‐Boc‐phenothiazine‐3,7‐diamine (BocPTDA), that can be used as a solid‐state organic TTI dye, exhibiting an irreversible change from colorless to blue green upon heating. The conversion properties, studied using a silicagel‐coated plate, confirmed that BocPTDA undergoes a color change above 20 °C. At temperatures of 4 °C and below, no visible changes are exhibited, making BocPTDA a well‐suited marker for monitoring abrupt temperature deviations indicating improper cold‐chain management. Thus, application of BocPTDA‐based TTI systems on packages could inform consumers about the cold‐chain maintenance, assuring quality and safe consumption. [ABSTRACT FROM AUTHOR]

By using tritopic and ditopic organic linkers derived from the same 2,4,6‐triphenylpyridine core, copper(II) metal‐organic frameworks with different three‐dimensional structures have been successfully synthesized under ambient conditions. The crystalline framework, PTBMOF ([Cu3(PTB)2(H2O)3]n, where H3PTB=4,4′,4′′‐(pyridine‐2,4,6‐triyl)tribenzoic acid, was observed to be mesoporous in nature and exhibited dual functionality in the removal of organic dyes. While cationic dyes such as methylene blue and malachite green, which are of different sizes, were adsorbed by PTBMOF; anionic dyes such as tartrazine could be effectively degraded in a photo‐Fenton‐like reaction catalyzed by the MOFs under irradiation with visible light. [ABSTRACT FROM AUTHOR]