Methyl Orange Solution Research Articles

Synthesis of an Environmentally Friendly Boron Nitride/Dye Composite Photocatalytic Material and Study on Degradation Mechanism of Tetracycline Wastewater

AbstractHerein, a boron nitride‐dye composite photocatalytic material is synthesized by a simple and environmentally friendly method. In this method, boron nitride (BN) is added to Methylene blue (MB), Congo red (CR), Rhodamine B (RhB), methyl orange (MO) solution respectively, the formed composites (BN‐RhB, BN‐MB, BN‐MO and BN‐CR) can further work as photocatalyst to degrade tetracycline (TC) under visible light irradiation. The degradation rate of TC are 278.5, 303.3, 89 and 115.5 times by BN‐RhB, BN‐MB, BN‐MO and BN‐CR higher than that of BN. This is from the sensitization of dyes for BN and these dyes have different absorption ranges for visible light. After the adsorption of BN for RhB‐MO, RhB‐CR, MB‐MO and MB‐CR mixed solutions, BN‐RhB‐MO, BN‐RhB‐CR, BN‐MB‐MO and BN‐MB‐CR composites are formed. Compared with BN, their photodegradation rate for TC are improved by about 102.75, 118, 388 and 460.75 times, respectively. The photodegradation rate of BN‐MB‐CR (k=0.01843) is better than that of BN‐MB (k=0.01213), being from that binary dyes are more conducive to improve the electron transfer efficiency than single dyes. The involved photo‐active species during photodegradation process and the photodegradation intermediate products of TC have detected as well. The photodegradation rate (k=0.01213) of BN‐MB for TC is also higher than that of g‐C3N4 (k=0.00599), g‐C3N4‐MB (k=0.01027), TiO2 (k=0.01061) and TiO2‐MB (k=0.01163). This work is helpful to develop an environment‐friendly water treatment material.

Superhydrophilic wollastonite-nanoTiO2 composite photocatalyst prepared by a wet grinding method: The effects of carriers and their application in the self-cleaning coatings

A wollastonite-nanoTiO2 composite (WOT-PC) was prepared by a facile mechanochemistry method, which is expected to improve the photocatalytic performance and its recycling ability. According to the results of photocatalytic degradation, the degradation extent of the 10 ppm (10 mg/L) methyl orange solution was 99% after 20 min UV irradiation, indicating the good photocatalytic performance of WOT-PC. The XPS results suggests that stable Ca–O–Ti and Si–O–Ti bind wollastonite and nanoTiO2 together chemically. Furthermore, Ca–O–Ti may promote the separation efficiency of photoinduced electrons and holes during irradiation. To study the bending of energy structures of nanoTiO2, UPS was used. The results showed a negative shift of the energy structure bands and a positive shift of the Fermi level to TiO2, revealing that electrons more easily move to the surface of TiO2 after wollastonite supports nanoTiO2. The WOT-PC coating exhibits great self-cleaning ability because of its superhydrophilicity and photocatalytic performance, reflecting the promise of WOT-PC as an outdoor wall coating in practical applications.

Ferroelectric polarization effect on the photocatalytic activity of Bi0.9Ca0.1FeO3/CdS S-scheme nanocomposites

BiFeO3 (BFO), as a kind of narrow band-gap semiconductor material, has gradually emerged advantages in the application of photocatalysis. In this paper, Ca doped BFO nanoparticles Bi0.9Ca0.1FeO3 (BCFO) were prepared by sol-gel method. And BCFO and CdS nanocomposites with two morphologies were obtained by controlling the time of loading CdS under a low temperature liquid phase process. It is found that the band gap becomes narrower after doping Ca into BFO, which is conducive to the absorption of visible light. Among all the samples, the composite of CdS nanowires and BCFO nanoparticles obtained by reaction time of 10 min has the best photocatalytic performance. The degradation rate of Methyl Orange solution was 94% after 90 min under visible light irradiation, which was much higher than that of pure BCFO and CdS. Furthermore, significant enhancement in the degradation rate (100% degradation in 60 min) can be achieved in poled samples after electric polarization process. The highest degradation rate is due to the promoted separation of photogenerated carriers induced by the internal polarization field and the formation of S-scheme heterostructure between BCFO and CdS. Such BCFO-CdS nanocomposites may bring new insights into designing highly efficient photocatalyst.

Preparation of pyridine-modified cotton fibers for anionic dye treatment

In order to prepare low-cost, biodegradable and processable adsorbent materials, and also provide a new solution for textile dyeing, novel modified cottons were obtained by introducing 4-aminopyridin into the surface of cotton fibers, and used for the removal of the anionic dyes from aqueous solution. The two modified cottons were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), which confirmed the amino groups and pyridine groups grafted onto the surface of modified cottons. The maximum adsorption capacities for congo red, methyl orange and orange II were 984.87 mg/g (pH = 12), 489.8 mg/g (pH = 8.5) and 599.66 mg/g (pH = 8), respectively. Kinetic and isotherm studies were carried out to investigate the adsorption behavior of the modified cottons on the anionic dyes. The results showed that the adsorption of the anionic dyes by modified cottons followed a pseudo-second-order kinetic model, the equilibrium data was well consistent with the Langmuir isotherm model, and chemisorption and monolayer adsorption were the main adsorption mechanisms. The reuse efficiency of modified cotton was over 80% after six cycles. In addition, the presence of cationic dyes has almost no effect on the adsorption of anionic dyes, and the modified cotton exhibited highly selective adsorption of methyl orange in mixed solutions of methyl orange and methylene blue. This paper also provided a new solution for textile dyeing.

Contact-electro-catalysis for the degradation of organic pollutants using pristine dielectric powders

Mechanochemistry has been studied for some time, but research on the reactivity of charges exchanged by contact-electrification (CE) during mechanical stimulation remains scarce. Here, we demonstrate that electrons transferred during the CE between pristine dielectric powders and water can be utilized to directly catalyze reactions without the use of conventional catalysts. Specifically, frequent CE at Fluorinated Ethylene Propylene (FEP) - water interface induces electron-exchanges, thus forming reactive oxygen species for the degradation of an aqueous methyl orange solution. Contact-electro-catalysis, by conjunction of CE, mechanochemistry and catalysis, has been proposed as a general mechanism, which has been demonstrated to be effective for various dielectric materials, such as Teflon, Nylon-6,6 and rubber. This original catalytic principle not only expands the range of catalytic materials, but also enables us to envisage catalytic processes through mechano-induced contact-electrification.

Sorption-photocatalytic performance of NbOx nanocrystals synthesized via heat-stimulated oxidation of niobium carbide

In this work, nano-sized niobium oxides with different crystal structures can be produced by thermal treatment of nonstoichiometric nanocrystalline niobium carbide (NbCy) and serve as effective sorbents and photocatalytic materials. Differential thermal analysis of initial NbCy powder was carried out, and temperatures of thermal treatment for the were chosen. The nanopowders were studied using powder X-ray diffraction, scanning electron microscopy, low-temperature N2 adsorption–desorption, X-ray photoelectron spectroscopy and diffuse reflectance electron spectroscopy methods. The specific surface area of samples annealed at 100, 200, 300, 400, 500 °C was about 224, 255, 273, 224 and 47 m2/g, respectively. The photocatalytic activity of the obtained nanopowders was analyzed during the oxidation of an aqueous solution of methyl orange on exposure to visible light. The photocatalytic activity of nanopowders grows with the annealing temperature increasing from 100 to 500 °C and reaches the maximum value for the higher niobium oxide Nb2O5. The time of complete decoloration of dye was 165 min. The tests performed to establish the sorption equilibrium between catalyst and dye in the dark revealed that the nanopowder produced during annealing at 300 °C possesses a high sorption capacity of 76.5%, which allows it to be considered as an effective sorbent.

Production and Optimization of Bio-Based Silica Nanoparticle from Teff Straw (Eragrostis tef) Using RSM-Based Modeling, Characterization Aspects, and Adsorption Efficacy of Methyl Orange Dye

The brown teff straw was utilized in this study to produce silica using the sol-gel technique. After pretreatment, the raw material of brown teff straw was characterized. The data were analyzed using the central composite design and response surface technique, and four independent parameters, namely, temperature, NaOH concentration, rotational speed, and extraction time, were evaluated for process optimization. Before extracting silica with an alkaline solution, the silica content in the ash was determined using an AAS spectrometer. The silica content of teff straw ash is around 92.89%. The ash was treated with NaOH solution in the concentrations range of 1 M to 3 M (0.5 M interval). The extraction time varied at intervals of 55, 70, 85, 100, and 115 minutes. Temperatures were changed using magnetic stirrer equipment in the range of 80°C to 100°C (5°C interval). At 350 rpm, 400 rpm, 450 rpm, 500 rpm, and 550 rpm, the rotating speed was adjusted. The best extraction conditions for amorphous silica were 1.50 M NaOH, 109.99 min, 94.98°C, and a rotating speed of 499.57 rpm, with a maximum yield of 85.85%. XRD and FTIR analyses were used to assess the physicochemical characteristics of the extracted silica. The aqueous solutions of methyl orange were used to test the adsorption efficiency of silica. The percent of removal efficiency for methyl orange was 90.48%.

Efficient adsorption of methyl orange and methyl blue dyes by a novel triptycene-based hyper-crosslinked porous polymer.

It is still a great challenge to develop new materials for the highly efficient entrapment of organic dyes from aqueous solution. Herein, a novel triptycene-based hyper-crosslinked porous polymer (TPP–PP) was designed and synthesized by a simple Friedel–Crafts reaction. The obtained polymer TPP–PP has a high surface area, abundant pore structure and stable thermal performance. Due to the above characteristics, TPP–PP has good adsorption performance for anionic methyl orange solution (MO) and cationic methyl blue solution (MB). Under the optimal experiment conditions, the TPP–PP showed an excellent adsorption capacity for MO (220.82 mg g−1) and MB (159.80 mg g−1), respectively. The adsorption kinetics fitted the pseudo-second-order model. The adsorption of MO by TPP–PP reaches equilibrium within 180 minutes, and the adsorption of MB reaches equilibrium within 150 minutes. The adsorption behavior was not only spontaneous but also endothermic in reality. At the same time, TPP–PP also has good reusability. After 5 cycles of experiments, the removal rate of MO and MB by TPP–PP can still reach more than 80%. Thus, the Friedel–Crafts reaction crosslinked method might be a promising approach for the synthesis of novel material for the highly efficient extraction of dye wastewater.

Orange dye Removal Efficiency by Few-layer Graphene: an Investigation by UV-Vis Spectroscopy-=SUP=-*-=/SUP=-

Nowadays, few-layer graphene (FLG) has been introduced as a new type of adsorbent. In this research, the orange dyes including, methyl orange (MO) as an industrial dye and the soft drink orange dye (orange Fanta soda) as a food dye, have been removed by FLG adsorbent. In all steps, UV-Vis spectroscopy as a valuable and fast method has been applied. The optical absorption coefficient has been decreased from 0.9 to less than 0.2 by FLG adsorbent for 50 ppm MO dye solution. Therefore, the MO solution with 50 ppm concentration converts to about 10 ppm output solution using 0.05 g of FLG adsorbent in a few minutes. It is about 80% adsorption dye removal efficiency. Also, MO dye removals have been performed in the range of 10 ppm to 500 ppm concentrations, but as the concentration of the solution increases, the dye adsorption ability of FLG decreases. The maximum efficient and optimum MO dye concentrations are about 100 ppm and 50 ppm, respectively, due to 0.05 g FLG adsorbent. It has been completely saturated at about 500 ppm concentration MO dye solution. Also, it has been observed that, for 50 ppm MO dye solution, increasing the amount of mass adsorbent from 0.05 g to 0.25 g can cause the output MO concentration to decrease from 10 ppm to 3 ppm. It has been revealed that about 94% of MO dye can remove by 0.25 g FLG adsorbent. The contact time due to 94% MO removal process is less than 5 minutes. Therefore, only by 0.25 g of FLG adsorbent we can purify wastewater containing 50 ppm MO dye to less than 3 ppm dye concentration, at less than a few minutes. Finally, the FLG glass tube filter can remove more than 90% food orange dye in less than 90 seconds for 50 ml of soft drink solution. Therefore, the FLG tube filtration process is so fast, easy, and high efficient. Keywords: adsorption, Few-Layer Graphene, methyl orange, UV-Vis spectroscopy, orange dye.

Orange dye removal efficiency by few-layer graphene: an investigation by UV-Vis spectroscopy

Nowadays, few-layer graphene (FLG) has been introduced as a new type of adsorbent. In this research the orange dyes including methyl orange (MO) as an industrial dye and the soft drink orange dye (orange Fanta soda) as a food dye have been removed by FLG adsorbent. In all steps UV-Vis spectroscopy as a valuable and fast method has been applied. The optical absorption coefficient has been decreased from 0.9 to less than 0.2 by FLG adsorbent for 50 ppm MO dye solution. Therefore, the MO solution with 50 ppm concentration converts to about 10 ppm output solution using 0.05 g of FLG adsorbent in a few minutes. It is about 80% adsorption dye removal efficiency. Also, MO dye removals have been performed in the range of 10 ppm to 500 ppm concentrations, but as the concentration of the solution increases, the dye adsorption ability of FLG decreases.The maximum efficient and optimum MO dye concentrations are about 100 ppm and 50 ppm, respectively, due to 0.05 g FLG adsorbent. It has been completely saturated at about 500 ppm concentration MO dye solution.Also, it has been observed that for 50 ppm MO dye solution increasing the amount of mass adsorbent from 0.05 g to 0.25 g can cause the output MO concentration to decrease from 10 ppm to 3 ppm. It has been revealed that about 94% of MO dye can remove by 0.25 g FLG adsorbent. The contact time due to 94% MO removal process is less than 5 minutes. Therefore, only by 0.25 g of FLG adsorbent we can purify wastewater containing 50 ppm MO dye to less than 3 ppm dye concentration, at less than a few minutes. Finally, the FLG glass tube filter can remove more than 90% food orange dye in less than 90 seconds for 50 ml of soft drink solution. Therefore, the FLG tube filtration process is so fast, easy, and high efficient. Key words: adsorption, few-layer graphene, methyl orange, UV-Vis spectroscopy, orange dye.

Studies on Synthesis and Characterization of Fe3O4@SiO2@Ru Hybrid Magnetic Composites for Reusable Photocatalytic Application

Degradation of dye pollutants by the photocatalytic process has been regarded as the most efficient green method for removal organic dyes from contaminated water. The current research work describes the synthesis of Fe3O4@SiO2@Ru hybrid magnetic composites (HMCs) and their photocatalytic degradation of two azo dye pollutants, methyl orange (MO) and methyl red (MR), under irradiation of visible light. The synthesis of Fe3O4@SiO2@Ru HMCs involves three stages, including synthesis of Fe3O4 magnetic microspheres (MMSs), followed by silica (SiO2) coating to get Fe3O4@SiO2 MMSs, and then incorporation of presynthesized Ru nanoparticles (~3 nm) onto the surface of Fe3O4@SiO2 HMCs. The synthesized HMCs were characterized by XRD, FTIR, TEM, EDS, XPS, BET analysis, UV-DRS, PL spectroscopy, and VSM to study the physical and chemical properties. Furthermore, the narrow band gap energy of the HMC photocatalyst is a significant parameter that provides high photocatalytic properties due to the high light adsorption. The photocatalytic activity of synthesized Fe3O4@SiO2@Ru HMCs was assessed by researching their ability to degrade the aqueous solution of MO and MR dyes under visible radiation, and the influence of various functional parameters on photocatalytic degradation has also been studied. The results indicate that the photocatalytic degradation of MO and MR dyes is more than 90%, and acid media favors better degradation. The probable mechanism of photodegradation of azo dyes by Fe3O4@SiO2@Ru HMC catalysts has been proposed. Furthermore, due to the strong ferromagnetic Fe3O4 core, HMCs were easily separated from the solution after the photocatalytic degradation process for reuse. Also, the photocatalytic activity after six cycles of use is greater than 90%, suggesting the stability of the synthesized Fe3O4@SiO2@Ru HMCs.

Nano ZNO and surface modification ZNO with graphite oxide deposition to enhance the catalytic activity

Preparation of ZnO nanoparticles and surface modification ZnO with the carbon material graphite oxide, were synthesized. The synthesized materials were characterized by PXRD, FT-IR, and UV-visible analysis. The materials show better optical and structural properties, which are beneficial in the photocatalytic degradation studies. Under light, zinc oxide and graphite oxide were used to degrade the methyl orange solution. The prepared materials by sol-gel preparation showed enhanced catalytic activity in the photocatalytic activity of methyl orange. An optimal loading content of graphite oxide was investigated. The enhanced photocatalysis was studied in detail. The study provides a promising application for the photocatalytic degradation of organic pollutants in photocatalysis. In the present work, the authors included the new novel materials of ZnO. The ZnO is modified with the surface deposits of rGO. The combined materials of semiconductor materials show a better response to light for the degradation studies. The use of such a combination is a new study and the results reflect the modification of semiconductor materials in the p-block elements such as C, N, F, P and so on for the enhanced photocatalytic applications of semiconductor mediated materials, which are widely used in photocatalysis. The PXRD analysis of ZnO and rGO shows better crystallinity in the case of ZnO, whereas after the deposition of rGO, crystallinity is lost due to the overlap of the main base material semiconductors, which explains the new catalytic and recombination effects of the materials used.

Statistical Analysis of Synthesis Parameters to Fabricate PVDF/PVP/TiO2 Membranes via Phase-Inversion with Enhanced Filtration Performance and Photocatalytic Properties

Non-solvent induced phase-inversion is one of the most used methods to fabricate membranes. However, there are only a few studies supported by statistical analysis on how the different fabrication conditions affect the formation and performance of membranes. In this paper, a central composite design was employed to analyze how different fabrication conditions affect the pure water flux, pore size, and photocatalytic activity of polyvinylidene fluoride (PVDF) membranes. Polyvinylpyrrolidone (PVP) was used to form pores, and titanium dioxide (TiO2) to ensure the photocatalytic activity of the membranes. The studied bath temperatures (15 to 25 °C) and evaporation times (0 to 60 s) did not significantly affect the pore size and pure water flux of the membranes. The concentration of PVDF (12.5 to 17.5%) affected the viscosity, formation capability, and pore sizes. PVDF at high concentrations resulted in membranes with small pore sizes. PVP affected the pore size and should be used to a limited extent to avoid possible hole formation. TiO2 contents were responsible for the decolorization of a methyl orange solution (10−5 M) up to 90% over the period studied (30 h). A higher content of TiO2 did not increase the decolorization rate. Acidic conditions increased the photocatalytic activity of the TiO2-membranes.

Adsorption kinetics of simulated mixture wastewaters over porous Bi2MoO6@BiOCl@MOF-199 heterostructure

In this work, we mainly investigate the adsorption properties of the simulated single and mixture wastewaters over porous Bi2MoO6@BiOCl@MOF-199 (BMO@BOC@MOF-199), including methylene blue (MB), rhodamine blue (RhB), methyl orange (MO) and chromium (VI). It is found that BMO@BOC@MOF-199 has a high adsorption capacity for MB, but a poor adsorption capacity for MO. Specifically, for single MB solution, 67%, 80% and 96% of MB are adsorbed by BMO@BOC, MOF-199 and BMO@BOC@MOF-199, respectively. The higher adsorption capacity of BMO@BOC@MOF-199 could be due to its higher surface area and larger pore volume. For single MO solution, nevertheless, only 16%, 13% and 7% of MO are adsorbed by BMO@BOC, MOF-199 and BMO@BOC@MOF-199, respectively. The different adsorption efficiency for MB and MO could be relative to their different molecular structures, which have different electrostatic interactions with adsorbent surface. For single RhB and single Cr(VI) solution, BMO@BOC@MOF-199 has adsorbed 30% RhB and 10% Cr(VI). In RhB-MO mixture solution, 32% RhB and 9% MO can be adsorbed by BMO@BOC@MOF-199, while in Cr(VI)–RhB-MO mixture solution, 7% Cr(VI), 3% RhB and 42% MO can be adsorbed by BMO@BOC@MOF-199. It is seen that in RhB-MO mixture solution, the adsorption efficiencies of RhB and MO by BMO@BOC@MOF-199 do not obviously change as compared to single RhB and single MO solution, while in Cr(VI)–RhB-MO mixture solution, the adsorption efficiency of MO has increased by 5 times, compared to single MO solution; but the adsorption efficiency of RhB has decreased by 9.7 times as compared to single RhB solution, and the adsorption efficiency of Cr(VI) has decreased slightly, compared to single Cr(VI) solution. The results are mainly attributed to the competitive adsorption on the adsorbent surface. This work can help us to understand the adsorption process for practical wastewater.

The Adsorption Performance of Polyaniline/ZnO Synthesized through a Two-Step Method

Polyaniline/Zinc oxide (PANI/ZnO) were prepared using a two-step method, and the morphology and the structure of PANI/ZnO composites were characterized through a scanning electron microscope (SEM) and X-ray diffraction (XRD). Factors such as the content of ZnO, the adsorption time and the mass of the adsorbent, and the kinetic equation of PANI/ZnO as adsorbents for the adsorption of methyl orange solution were studied. The results showed that the adsorption efficiency of methyl orange by polyaniline with the increase of adsorbent mass firstly increased and then decreased. Among the composites with the same quality, PANI composites with 8% ZnO have a better adsorption effect for methyl orange, and the maximum adsorption ratio can reach 69% with the increase of adsorption time at 0.033 g; With the increase of adsorbent mass, the adsorption efficiency of PANI composites with 8% ZnO increased continuously. When the mass increased from 0.033 g to 0.132 g, the adsorption rate increased from 69% to 93%, and the adsorption of the methyl orange solution by PANI/ZnO composites was more in line with the quasi-second-order kinetic equation.

CQD/TiO2 nanocomposite photocatalyst for efficient visible light-driven purification of wastewater containing methyl orange dye

In this study, we report a cost effective and facile synthesis method for preparing carbon quantum dot incorporated TiO2 nanocomposite (CQD/TiO2) for rapid photodegradation of methyl orange (MO) under direct and indirect sun irradiations. In practice, TiO2 nanosols and CQD were prepared by sol-gel and hydrothermal routes, subsequently their nanocomposites (CQD/TiO2) by sonication assisted mixing process at ambient conditions. Different analyses like XRD, FTIR and SEM/EDX. TEM, XPS, Zeta-potential were employed to characterize the prepared catalysts. CQD/TiO2 prepared in the weight ratio of 1:10 of CQD and TiO2 exhibited optimized MO-photodegradation (three folded to the activity of pure TiO2) in direct sunlight exposures at pH 11. The results show that variations in the initial concentration and pH of MO solution as well as catalyst loadings have a significant impact on the photocatalytic performance of CQD/TiO2. Similar MO-percentage degradations for five consecutive cycles highlighted its long-term catalytic stability and good reusability potential. Because of good visible-light photocatalytic efficiency, profound catalytic-stability, and reusability for dyes photocatalysis, CQD/TiO2 nanohybrid is a potential candidate for photocatalytic purification of textile and other organic based wastewater under direct and indirect solar light exposures.

Effect of Ag doped MnO2 nanostructures suitable for wastewater treatment and other environmental pollutant applications

A modest sol-gel method has been employed to prepare the pure and Ag doped MnO2 nanoparticles and methodologically studied their physical, morphological, and photosensitive properties through XRD, TEM, EDAX, Raman, UV, PL and N2 adsorption - desorption study. Tetragonal crystalline arrangement with spherical nanoparticles was found out through XRD and TEM studies. The EDAX studies further supported that formation Ag in the MnO2 crystal matrix. The bandgap energy of Ag doped MnO2 was absorbed through UV spectra. Photo -generated recombination process and surface related defects were further recognized by PL spectra. Through visible light irradiation, the photo - degradation of methyl orange (MO) and phenol dye solutions were observed. The optimum condition of (10 wt% of Ag) Ag doped MnO2 catalyst showed tremendous photocatalytic efficiency towards MO than phenol under same experimental study.

Research of Interaction Processes of Fast and Thermal Neutrons with Solution of Organic Dye Methyl Orange

The emergence of powerful sources of ionizing radiation, the needs of nuclear energy, technology and medicine, as well as the need to develop reliable methods of protection against the harmful effects of penetrating radiation stimulated the development of such branches of science as radiation chemistry, radiation biology, radiation medicine. When an organic dye solution is exposed to ionizing radiation, it irreversibly changes color. As a result, the absorbed dose can be determined. The processes of interaction of neutron fluxes with an aqueous solution of an organic dye methyl orange (МО) – C14H14N3О3SNa, containing and not containing 4% boric acid, have been investigated. The work was carried out on a LINAC LUE-300 at NSC KIPT. A set of tungsten plates was used as a neutron-generating target. The electron energy was 15 MeV, the average current was 20 μA. The samples were located behind the lead shield and without it, with and without a moderator. Using the GEANT4 toolkit code for this experiment, neutron fluxes and their energy spectra were calculated at the location of experimental samples without a moderator and with a moderator of different thickness (1-5 cm). An analysis of the experimental results showed that when objects without lead shielding and without a moderator are irradiated, the dye molecules are completely destroyed. In the presence of lead protection, 10% destruction of the dye molecules was observed. When a five-centimeter polyethylene moderator was installed behind the lead shield, the destruction of dye molecules without boric acid on thermal neutrons was practically not observed. When the fluxes of thermal and epithermal neutrons interacted with a dye solution containing 4% boric acid, 30% destruction of dye molecules was observed due to the exothermic reaction 10B (n, α). The research has shown that solutions of organic dyes are a good material for creating detectors for recording fluxes of thermal and epithermal neutrons. Such detectors can be used for radioecological monitoring of the environment, in nuclear power engineering and nuclear medicine, and in the field of neutron capture therapy research in particular.

Synthesis of highly sensitive nanomaterial for ultra-fast photocatalytic activity: A detailed study on photocatalytic capabilities of rod-shaped TiS3 nanostructures

Two-dimensional TiS3-nanostructures have been used to successfully remove toxic-industrial pollutants such as methyl-orange(MO) and methyl-blue(MB) from water bodies. Two-dimensional TiS3-nanostructures with exceptional mobility properties have been produced using the chemical vapor transport(CVT) technique and its photocatalytic capabilities are examined for potential environmental applications.Under infrared(IR) irradiation, the produced TiS3-nanoribbons were evaluated for their ability to degrade MO and MB solutions. TiS3-nanoribbons reveal significant high disintegration percentage; it is capable to decompose 90.3% of 50 μM MO pollutant solution in 5 min. Moreover it decomposes 94.4% of 50 μM MO solution as well as 10 μM MB solution in 20 min and 12 min, respectively.

Comparative study on photooxidation of methyl orange using various UV/oxidant systems

Abstract In the present work, a comparative study of the photooxidation of an aqueous solution of Methyl Orange (MeO) has been realized using H2O2 and IO3 −, BrO3 −, ClO3 −, ClO4 −, BO3 − ions in the presence of UV low pressure mercury lamp (UV-C light at λ max = 254 nm). The initial concentration of MeO in all experiments was 6 × 10−5 mol L−1. The degradation rate of MeO follows pseudo-first-order kinetics in all UV/Oxidant systems. The highest degradation rate of MeO was in the BrO3 −/UV254nm system. Different systems were compared for an oxidant concentration of 10−2 mol L−1 and the obtained results showed that decolorization followed the decreasing order: BrO 3 − /UV 254 nm > IO 3 − /UV 254 nm > H 2 O 2 /UV 254 nm > BO 3 − /UV 254 nm > ClO 3 − /UV 254 nm = ClO 4 − /UV 254 nm = UV 254 nm . The optimization of oxidants concentration for each process was determined (10−2 mol L−1 for IO3 − which gives almost the same k app for 5 × 10−3, 10−2 mol L−1 for BO3 − and 5 × 10−2 mol L−1 for H2O2). No degradation of MeO in presence of ClO3 − and ClO4 − because these ions do not absorb at 254 nm, therefore they do not generate radical species which degrade organic pollutants. The mineralization was also studied where it was reached 97% after 5 h of irradiation for both H2O2/UV254 nm and BO3 −/UV254 nm systems.