Methylene Blue Reaction Research Articles

Highly efficient solution grown CuXO/Cu nanostructures for catalytic reduction of nitroarenes and visual colorimetric detection of Zn2+ using clock reaction of methylene blue

Highly efficient solution grown CuXO/Cu nanostructures for catalytic reduction of nitroarenes and visual colorimetric detection of Zn2+ using clock reaction of methylene blue

Study of the Photocatalytic Activity of Titanium and Tungsten Oxides Obtained by Electric Explosion of Metal Conductors in Air

Oxides as a shape of micro- and nanosized powder, containing agglomerates of particles with a high specific surface, were obtained by means of electric Ti and W wire explosion in the air. An X-ray phase analysis showed that the only product of Ti destruction is TiO2, while the electric explosion of W conductors results in the formation of WO3 + W2O7 mixture, which tungsten anhydride WO3 dominates in, and traces of a residual metallic W come across. The photocatalytic properties of electroexplosive powder were studied using a model oxidation reaction of methylene blue. It was revealed that both TiO2 and the WO3 + W2O7 mixture demonstrate catalytic activity within a wide spectrum of radiation, including the visible one. The catalytic activity of the WO3 + W2O7 mixture under ultraviolet and incandescent lamp radiation was inferior to that of TiO2, however, in the solar radiation, the rate of dye degradation with the participation of tungsten oxides is higher. In this case, the average rate of decreasing concentration of the dye in water containing a mixture of WO3 + W2O7 depends but a little on the type of the radiation source.

Study on decolorization of methylene blue with a kind of electrolytic active water

Electrolytic active water was prepared by electrolytic treatment of sodium chloride aqueous solution using a self-made device. In order to investigate the properties of electrolytic active water , the pH value, available chlorine contents and decolorization ability on methylene blue solution were tested and compared with that of sodium hypochlorite aqueous solution. Experimental results showed that the electrolytic active water has higher oxidation capacity and decolorization efficiency for methylene blue compared with sodium hypochlorite solution, implying maybe other reactive oxygen species components besides hypochlorite existed in the electrolytic active water. The electrolytic active water was stable under long-term storage, and mechanical force with oxidation activity did not decrease. In addition, the decolorization kinetics of methylene blue in the electrolytic active water was explored, and it was found that, in general, the decolorization reaction of methylene blue in electrolytic active water was consistent with the first-order reaction kinetics model, but when the pH value of electrolytic active water solution was weakly alkaline or neutral, the decolorization reaction of methylene blue was closer to the second-order reaction kinetics model.

Cathodoluminescence Spectroscopy of Complex Dendritic Au Architectures for Application in Plasmon‐Mediated Photocatalysis and as SERS Substrates

AbstractComplex 3D metallic nanostructures with large surface areas and broadband absorption are attractive candidates for efficient photocatalysis and spectroscopy. Here, hierarchical Au dendrites are self‐assembled over centimeter‐scales by electrodeposition and the plasmon modes are locally mapped using cathodoluminescence spectroscopy. A correlation between the spatial and spectral distribution of the plasmonic “hot‐spots” and the morphology of these structures are demonstrated. Electrodynamic simulations show that the spectra of the plasmon modes are determined by the local geometry of sharp features. Their performance as both surface‐enhanced Raman scattering (SERS) substrates and as photocatalysts for the N‐demethylation reaction of methylene blue is investigated. High hot‐spot densities result in larger SERS enhancement, while the sample with the lowest hot‐spot density has a reaction yield 136% larger than the sample with the highest density. These findings indicate that maximizing the hot‐spot density is not sufficient to optimize plasmonic substrates for all applications. The spectral and spatial distribution of the plasmon resonances will modify the hot electron generation efficiency and need to be considered for plasmon‐enhanced photocatalysis. This work extends the understanding of light–matter interactions in complex 3D structures and provides direction for the rational design of plasmonic architectures for different applications.

The impact of magnetized drinking water on semen quality, fertility and hatchability rates of Fayoumi chicken

The present study was conducted to interpret the effect of magnetic field on water pH and calcium form, and evaluate semen quality, fertility and hatchability rates of Fayoumi chickens receiving magnetized drinking water (MDW). A total of 180 Fayoumi chickens (20 roosters + 160 hens), 54 weeks of age, were divided into two groups. The first group served as control, which received regular drinking water, and the second group was treated with MDW. Semen was collected twice (at day 15 and day 30 of the experiment) to determine semen quality. Fertility and hatchability were determined in two patches of hatching eggs through 1–15 and 16–30 days of the experiment. Results showed that the roosters of MDW group had higher live sperm and sperm motility ratios than those of the control group throughout the experimental period (1–30 days). The abnormal sperm ratio and methylene blue reaction time of MDW-received roosters were significantly lower than those of control roosters. Fertility and hatchability percentages of MDW group were greater compared to those of regular drinking water. Conclusively, alterations in the physiochemical characteristics of MDW and the calcium form can play a role in improving semen quality, fertility, and hatchability percentages during the late laying phase.

The impact of H2O/C2H5OH solvents on the properties of Fenton CuFe2O4 photocatalysts for the degradation reaction of methylene blue

This paper reported a simple method of co-precipitation in aqueous and ethanol solvent systems to prepare a catalyze CuFe2O4 heterogeneous Fenton used for the degradation reaction of methylene blue (MB). The mixtures of oxalate precursors were prepared from the corresponding sulfate salts and oxalic acid in the solvent system of H2O/C2H5OH. The heat treatment of the precursor mixtures was carried out at 600, 700, and 800 oC in the surrounding atmosphere. The change in the volume ratio of water and ethanol with the tendency to gradually decrease the volume of water lead to a decrease in the polarity of the solvent and affected the precursors' precipitation as well as the solid phase reaction. The decrease in the solvent polarity resulted in a slight increase of the particle size and a reduction of the crystallinity. The experimental results showed that the water-ethanol solvent system had the effect of reducing the degree of dispersion in terms of the particle size. Meanwhile, the increase of the precursor calcination temperature resulted in the increased grain size and the higher concentration of Fe3+ ions on the surface compared with samples heat-treated at 600 and 800 oC. Samples, prepared from the solvent system with the ethanol-water volume of 50% or 70%, and then were calcined at 700 oC, showed good catalytic ability for the MB decomposition reaction irradiated by UVA rays and oxalic acid being used as an oxidizing agent. The MB processing efficiency after 90 minutes was 85%.

Strategy to Design-Synthesize Bimetallic Nanostructures Using the Alcohol Reduction Method.

Bimetallic nanomaterials have attracted much attention from various fields such as catalysis, optics, magnetism, and so forth. The functionality of such particles is influenced very much by the intermetallic interactions than their individual contribution. However, compared with the synthesis of monometallic nanoparticles, the reaction parameters that need to be controlled for tuning the size, shape, composition, and crystal structure of bimetallic nanoparticles becomes challenging. This study focuses on synthesizing of bimetallic nanostructures using the alcohol reduction method, where the control over the reducing power is conceivable by varying the combination of the alcohol type, complexing agent, and metal salts. Consequently, various Cu-Co nanostructures such as Cu-Co core-shell (size ranged between 40 and 15 nm) and hollow alloy nanoparticles and nanotubes were successfully synthesized by incorporating diffusion and etching phenomena during the reduction reaction. Moreover, time-resolved sampling revealed that the formation of a Cu-Co alloy hollow nanostructure has been realized by the diffusion of the Cu core into the Co shell by controlling the reduction time gap between Cu and Co and the crystal structure besides the reduction sequences. It should be noted that the synthesis of a high-temperature (∼1300 °C) Cu-Co alloy phase was carried out at 170 °C. Among the Cu-Co alloy nanostructures, Cu-Co hollow alloy nanoparticles exhibited enhanced catalytic activity compared to metallic Cu and other Cu-Co nanostructures from the degradation reaction of methylene blue. The enhanced catalytic performance was considered to be mainly due to the alloy structure.

Electrochemical detection of carbendazim with mulberry fruit-like gold nanocrystal/multiple graphene aerogel and DNA cycle amplification.

An aptasensor for electrochemical detection of carbendazim is reported with mulberry fruit-like gold nanocrystal (MF-Au)/multiple graphene aerogel (MGA) and DNA cycle amplification. HAuCl4 was reduced by ascorbic acid in a CTAC solution containing KBr and KI and formed trioctahedron gold nanocrystal. The gold nanocrystal underwent structural evolution under enantioselective direction of l-cysteine. The resulting MF-Au shows a mulberry fruit-like nanostructure composed of gold nanocrystals of about 200 nm as the core and many irregular gold nanoparticles of about 30 nm as the shell. The exposure of high-index facets improves the catalytic activity of MF-Au. MF-Au/MGA was used for the construction of an aptasensor for electrochemical detection of carbendazim. The aptamer hybridizes with assistant strand DNA to form duplex DNA. Carbendazim binds with the formed duplex DNA to release assistant strand DNA, triggering one three-cascade DNA cycle. The utilization of a DNA cycle allows one carbendazim molecule to bring many methylene blue–labeled DNA fragments to the electrode surface. This promotes significant signal amplification due to the redox reaction of methylene blue. The detection signal is further enhanced by the catalysis of MF-Au and MGA towards the redox of methylene blue. A differential pulse voltammetric signal, best measured at − 0.32 V vs. Ag/AgCl, increases linearly with the carbendazim concentration ranging from 1.0 × 10−16 to 1.0 × 10−11 M with a detection limit of 4.4 × 10−17 M. The method provides ultrahigh sensitivity and selectivity and was successfully applied to the electrochemical detection of carbendazim in cucumber.Graphical abstract This study reports on an ultrasensitive aptasensor for electrochemical detection of carbendazim in cucumber based on mulberry fruit–like gold nanocrystal–multiple graphene aerogel and DNA cycle double amplification.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00604-021-04886-y.

Storage and delivery of H2S by microporous and mesoporous materials

Abstract Hydrogen sulphide has therapeutic functions but because it is a gas its delivery as a drug poses specific difficulties. Porous materials have been emerging as serious candidates for the storage and release of small gas molecules with therapeutic effects. In this work, we study microporous (A, and Y zeolites; ETS-4 and ETS-10 titanosilicates) and mesoporous (SBA-15 with and without surface amines functionalization) materials. The experimental determination of the H2S amounts released from the porous materials in liquid phase was challenging. For this, two methodologies were used, the detection through the methylene blue reaction and by a selective electrode. In the end, considering the storage amounts, the release profile and the cytotoxicity, 4A zeolite and ETS-10 titanosilicate showed the best properties.

Каталитические свойства продуктов гидролиза бромида иттрия

The effect of hydrolysis time, final pH of synthesis, and hydrothermal treatment on the for-mation of yttrium oxyhydroxides obtained by alkaline hydrolysis of yttrium bromide was studied. Hydrolysis was carried out at different duration of the hydrolytic agent addition: 5 minutes, 1 hours and 24 hours, as well as at different final pH values were checked: 8, 9 and 10. Methods for characterization of resulting materials were: thermogravimetry combined with differential scanning calorimetry and mass spectrometry of gaseous products of thermolysis, X-ray diffraction, high-resolution scanning electron microscopy with EDX elemental analysis. In addition, a photocatalytic activity of the obtained samples was evaluated in the decomposition reaction of methylene blue under the UV radiation. It is established that the hydrolysis of yttrium bromide involves the capture of a significant amount of impurities of bromide and carbonate ions, which are present in the structure of the samples. The physical and chemical characteristics of yttrium bromide hydrolysis products depend on both the pH value and hydrolysis duration, as well as on hydrothermal treatment. The latter significantly increases the crystallinity of the samples and their photocatalytic performance in destruction reaction of methylene blue.

Construction of detachable core/shell Fe3O4@C supported noble metal catalysts and their catalytic performance

In this article, magnetically responsive catalysts were successfully synthesized by host-guest chemistry and self-assembly strategy. Firstly, β-cyclodextrin (β-CD) was bound directly to the surface of core/shell magnetic Fe3O4@C (MFC) using chemical bonding methods. Then, in view of the host-guest recognition, p-aminothiophenol (pATP) was captured by β-CD to form inclusion complex on the surface of MFC. Lastly, pre-synthesized gold, silver, platinum nanoparticles (AuNPs, AgNPs, PtNPs) could be adsorbed on the surface of MFC@β-CD-pATP through self-assembly strategy to fabricate ternary composites MFC@β-CD-pATP@metal nanoparticles. Catalytic reduction reaction of methylene blue using NaBH4 as reducing agent evaluates the catalytic performance of three as-prepared magnetic nanocomposites. MFC@β-CD-pATP@AuNPs catalyst showed the fast catalytic reaction rate constant. Significantly, we have explored the separation of magnetic supports and novel metal nanoparticles under mild conditions. This strategy will become a green and environmental way for highly efficient separation of precious metals catalysts, and recycle and reuse of catalyst carriers.

Colorimetric determination of hydrazine and nitrite using catalytic effect of palladium nanoparticles on the reduction reaction of methylene blue

In this research, hydrazine and nitrite determination was performed based on the reaction of methylene blue with hydrazine in the presence of palladium nanoparticles (PdNPs) as catalyst. The system was monitored spectrophotometrically by measuring the decrease in the absorbance of the methylene blue at 662 nm. Subsequently the inhibitory effect of nitrite on this catalytic reaction was also used for nitrite determination. In fact the depigmentation of methylene blue was postponed by nitrite added to the reaction mixture containing methylene blue, hydrazine and PdNPs. This inhibitory effect enables us to measure nitrite. Several factors influencing the analytical performance of the kinetic method such as concentration of reactants and electrolyte, pH of the sample solution and temperature were studied to achieve the optimum conditions and highest sensitivity. The change in absorption intensity of methylene blue was linearly proportional to the concentration in the range of 6–600 μmol L−1 and 0.3–14.2 μmol L−1 with a limit of detection of 3.85 μmol L−1and 0.21 μmol L−1 for hydrazine and nitrite, respectively. The method was successfully applied to the determination of hydrazine in water samples and nitrite in water, meat and saliva samples.

Manganese-Containing Nanostructured Oxide Coatings on Titanium Formed by Plasma Electrolytic Oxidation

Nanostructured manganese-containing oxide coatings on titanium were formed by method of plasma electrolytic oxidation in tetraborate aqueous electrolyte containing manganese acetate with and without the acetonitrile addition. These oxide layers with high content of manganese and coated by ordered "leaf-like" mesh nanostructures are formed in the electrolyte without acetonitrile addition. The oxide layers are displayed high acitivity towards oxidation CO and photoactivity in the degradation reaction of methylene blue. The addition of acetonitrile into electrolyte results in the change in the morphology of the coating surface, a significant reduction in the manganese content and, as a consequence, practical loss of activity in the oxidation of CO in CO2 and a reduction in the photocatalytic activity in the decomposition of methylene blue.

PRODUCTIVE AND REPRODUCTIVE RESPONSES OF BREEDER JAPANESE QUAILS TO DIFFERENT DIETARY CRUDE PROTEIN AND L-VALINE LEVELS

The outcomes of dietary crude protein levels (CP; 18 and 20%) and L-valine (Val.; 0, 0.1 and 0.2%) supplementation on the productive/reproductive performance, egg quality and some blood parameters of breeder Japanese quails were evaluated from 14 to 28 weeks of age. One hundred forty-four birds were individually weighed and randomly distributed into six treatment groups with eight replicates each of two females and one male. Body weight, egg weight and percentages of fertility, hatchability and total embryonic mortality were not influenced by treatments. However, significant interactions due to CP and Val. levels on egg production percentage, egg mass, chick weight and egg quality traits were obtained. Quails fed 18% CP + 0.2% Val. diets had better feed and valine intake, FCR, shell thickness and yolk index. Sexual libido, foam production, sperm concentration and motility percentage and methylene blue reaction time (MBRT) did not differ due to treatments while cloacal gland area and semen ejaculate volume of male quail were significantly improved by 18% CP level. No differences between treatments were observed for blood urea and albumin concentrations of male and female. In contrast, total protein and Superoxide dismutase (SOD) concentrations increased significantly in response to Val. levels and were also enhanced differently in the blood of male and female. Superoxide dismutase concentration in the plasma of male was not influenced by treatments while plasma female's SOD was significantly elevated due to 18 % CP + 0.2 % Val. diet. The results indicated that dietary 18% CP with 0.2% L-valine was suitable for breeder quails at 14-28 weeks of age.

Ag and N co-doped TiO2 nanostructured photocatalyst for printing and dyeing wastewater

Ag and N co-doped TiO2 nanoparticles were synthesized by the sol–gel method. Tetrabutyl titanate was used as the precursor, AgNO3 as the Ag source, and urea as the N source. When the sol was prepared, a 304 stainless steel mesh as the structured material was immerged into the solution. After calcinated at preset temperature, nanostructured photocatalysts were obtained. The photocatalysts were located at the internal shell of a continuous reactor that was designed for photocatalytic reaction. The degradation reaction of methylene blue was carried out in this reactor. The characteristics and doping dosage of the nanostructured photocatalysts were analyzed by thermogravimetric analysis, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy. The degradation product samples were determined by UV–vis spectrometry. Finally, the photocatalytic efficiency was evaluated under batch and continuous reactors. The multifarious kinetic constants were determined under reaction conditions. The result illustrates that the degradation efficiency of methylene blue apparently increased.

Dual template synthesis and photoelectrochemical performance of 3-D hierarchical porous zinc oxide

In this work, a novel hierarchical porous ZnO is successfully synthesized through a sol–gel method, in which a kind of biological material is used as hard template, block copolymer Pluronic F127 as soft template. The phase and morphology of the products are characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and transmission electron microscope (TEM). The results show that the as-prepared ZnO with a hierarchical porous architecture is assembled by multiple-layered porous nanosheets, of which the pore structure is highly ordered. The photocatalytic activity of the as-prepared ZnO is evaluated by photodegradation reaction of methylene blue. The photoelectrochemical (PEC) property of the hierarchical porous ZnO film is also investigated in this work.

Kinetics analysis for development of a rate constant estimation model for ultrasonic degradation reaction of methylene blue

Ultrasound has been used as an advanced oxidation method for wastewater treatment. Sonochemical degradation of organic compounds in aqueous solution occurs by pyrolysis and/or reaction with hydroxyl radicals. Moreover, kinetics of sonochemical degradation has been proposed. However, the effect of ultrasonic frequency on degradation rate has not been investigated. In our previous study, a simple model for estimating the apparent degradation rate of methylene blue was proposed. In this study, sonochemical degradation of methylene blue was performed at various frequencies. Apparent degradation rate constant was evaluated assuming that sonochemical degradation of methylene blue was a first-order reaction. Specifically, we focused on effects of ultrasonic frequency and power on rate constant, and the applicability of our proposed model was demonstrated. Using this approach, maximum sonochemical degradation rate was observed at 490kHz, which agrees with a previous investigation into the effect of frequency on the sonochemical efficiency value evaluated by KI oxidation dosimetry. Degradation rate increased with ultrasonic power at every frequency. It was also observed that threshold power must be reached for the degradation reaction to progress. The initial methylene blue concentration and the apparent degradation rate constant have a relation of an inverse proportion. Our proposed model for estimating the apparent degradation rate constant using ultrasonic power and sonochemical efficiency value can apply to this study which extended the frequency and initial concentration range.

Mesoporous TiO2/WO3 hollow fibers with interior interconnected nanotubes for photocatalytic application

Mesoporous TiO2/WO3 hollow fibers with interconnected nanotubes were prepared by a sol–gel method using polysulfone hollow fibers as a framework template and a block copolymer as an internal template. Polysulfone fibers were immersed in a sol–gel solution and the oxides were deposited on the fibers by vacuum impregnation. The polysulfone and copolymer were removed by thermal treatment at 500 °C for 3 h to form the mesoporous hollow fibers. They preserved the shape and morphology of the polysulfone template after heat treatment. The structure and optical properties of the fibers were characterized, and the performance of the fibers for photocatalytic reaction of methylene blue was investigated. The mesoporous TiO2/WO3 hollow fibers possessed higher surface area (∼130 m2 g−1) and lower band gap energy than pure TiO2 fibers. They exhibited better photodegradation efficiency of methylene blue than TiO2 and WO3 fibers and P25 powder.

Size-controllable synthesis and enhanced photocatalytic activity of porous ZnS nanospheres

Size-controllable porous ZnS nanospheres consisting of nanoparticles have been successfully synthesized using an economical and simple chemical bath deposition. The results show that all the prepared nanospheres exhibit good size uniformity and regularity and are cubic ZnS structure. Moreover, the nanosphere surface is relatively rough and porous. It is interesting that the size and its distribution of ZnS nanospheres can be easily tuned by adjusting pH value. The photocatalytic activity of the ZnS nanospheres was evaluated by photodegradation reaction of methylene blue. The as-prepared ZnS nanospheres with smaller diameter exhibit enhanced photocatalytic activity, which is associated with the larger specific surface area and favorable dispersibility.

Synthesis of NdFeO<sub>3</sub> Perovskites in a Reverse Microemulsion and its Visible Light Photocatalytic Activity

The synthesis of NdFeO3 perovskites in a reverse microemulsion and its photocatalytic property for visible light degradation reaction of methylene blue were investigated, respectively. When the irradiation time prolonged from o to 90 minutes, the degradation rate for methylene blue could achieve 60%. XRD pattern shows that a well-crystallized perovskite structure is observed for the NdFeO3 sampled prepared. The TEM characterization result indicates that the dimension of NdFeO3 nanopowders is in the range of 35~45 nm, which is consistent with the calculation result using the Scherrer equation.