Degradation Of Methyl Orange Solution Research Articles

Degrade Methyl Orange by Combining Cu2O/Al2O3 and H2O2 as Catalyst

To efficiently degrade printing and dyeing wastewater at low costs, Cu2O/Al2O3 catalyst was prepared by electrochemical method. Under its combined action with H2O2, photocatalytic degradation of methyl orange solution, as simulated wastewater, was carried out. With the aid of X-ray diffractometer, X-ray microanalysis system and scanning electron microscope, the structure and composition of catalyst film were designed by adjusting the electrochemical parameters, and the performance of photocatalyst was evaluated by the degradation rate of methyl orange. It was found that after anodizing aluminum alloy for 2 h in a 2 mol/L H2SO4 solution under a voltage of 15 V, alumina film with reasonable pore size distribution could be prepared on the alloy surface. By electroplating the film in a 0.01 mol/L CuSO4 solution at 5°C, and then hydrothermally treating it at 200°C, the Cu2O/Al2O3 photocatalyst could be obtained. The prepared Cu2O/Al2O3 and 10% H2O2 were used jointly as photocatalyst to degrade 10 mg/L methyl orange solution for 480 min, which achieved a methyl orange degradation rate of up to 82.1%.

The Study on the Novel Complex Structure and Photocatalytic Degradation Ability of Manganese

The vigorous development of the dye industry has led to increasingly serious harm to the water environment. Currently, dye wastewater has become one of the most difficult industrial wastewater to degrade. Therefore, how to treat dye wastewater in a green and economical manner is receiving increasing attention. Photocatalytic technology has attracted much attention in the treatment of dye wastewater due to its advantages such as fast speed, no selectivity, and complete degradation. However, the current application of traditional photocatalytic materials is greatly limited due to the high recombination rate of photo generated charge carriers and the difficulty in separating and recovering powder catalysts. Therefore, it is of great significance to study the preparation and application of visible light response catalysts with high catalytic activity. The structure of the complex was characterized by X-ray single crystal diffractometer, and the manganese complex was determined by UV and IR spectroscopy, which was then used for the photocatalytic degradation of methyl orange solution.

Preparation of a Novel Copper–Cobalt Composite Catalyst and Study on Performance Degradation of Methyl Orange

A novel Co–Cu composite heterogeneous Fenton-like catalyst was prepared by using a modified hydrothermal method for the degradation of methyl orange solution. The catalyst was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and a Fourier transform infrared spectrometer (FT-IR), which confirmed that the catalyst contained Co(OH)2, Cu2O, and an exhibition of a hexagonal crystalline structure with sizes within the range of 0.5–5 μm. The influential factors were researched with the use of univariate analysis and the results showed that: the catalyst has better catalytic properties in the pH range of 2–10 and there was an optimum value of the dosage of the catalyst; the greater the dosage of the catalyst, the faster the COD degradation rate achieves its maximum value; the COD degradation rate increases with a higher reaction temperature. When the pH is 7, the dosage of the catalyst is 0.3 g/L, the dosage of hydrogen peroxide is 50 mL/L, and the reaction temperature is 313 K. The COD degradation rate reached 94% after 50 min of treatment, which proved that the catalyst exhibited high catalysis in a Fenton-like process. Furthermore, reuse of the catalyst and the degradation mechanism of methyl orange were also researched.

Tribo-Catalytic Degradation of Methyl Orange Solutions Enhanced by Silicon Single Crystals

Coating materials on the bottoms of reactors/beakers has emerged as an effective method to regulate tribo-catalytic reactions. In this study, silicon single crystals were coated on the bottoms of glass beakers, in which 30 mg/L methyl orange (MO) solutions suspended with alumina nanoparticles were subjected to magnetic stirring using Teflon magnetic rotary disks. With a gentle rotating speed of 400 rpm for the Teflon disks, the MO solutions were changed from yellow to colorless and the characteristic absorption peak of MO at 450 nm in the UV-Vis spectrum disappeared entirely within 120 min. Mass spectrometry tests were further performed to gain insights into the degradation process, which suggested that the degradation was initiated with the cleavage of the nitrogen-nitrogen double bond in ionized MO molecules by the attack of •OH radicals. Through comparison experiments, we established that the observed degradation was related to the friction between alumina and silicon during magnetic stirring, and hydroxyl and superoxide radicals were formed from the friction, according to electron paramagnetic resonance analysis. It is proposed that electron-hole pairs are excited in silicon single crystals through friction with alumina, which diffuse to the surface of the single crystals and result in the degradation.

The enhancement of photocatalytic activity of porous g-C3N4@TiO2 nanotubes heterostructure

The g-C3N4 nanosheets were uniformly grown on TiO2 nanotubes with porous structure via the improved methods of impregnation calcination and facial vapor deposition. The photocatalytic performance of the g-C3N4/TiO2 nanotubes was evaluated by the degradation of methyl orange solution (MO) and exhibited higher photodegradation rate than the pure g-C3N4 or TiO2 nanotubes under xenon light irradiation, which may be attributed to the increased specific surface area and efficiently separation of photon-generated electrons/holes by the heterostructure. This work provides a simple and efficient scheme of manufacturing porous heterostructure nanotubes for environmental and energy applications.

Synthesis of reusable and anti-fouling Co-Al-Ce LDHs coated stainless steel mesh for ultrafast oil/water separation and photocatalytic degradation

Industrial sewage containing oil and dye has already aroused the concerns of cosmopolites. Nowadays, membrane technology is regarded as the spotlight and highly-efficient treatment for various wastewater from human activities. Massive efforts have been put into newly synthesis of low-cost, eco-friendly, low energy consumption, reusable and robust Co-Al-Ce LDHs coated stainless steel mesh (SSM) for wastewater treatment. The CoAlCe-LDHs SSM was fabricated by facile hydrothermal method successfully. While the pristine SSM didn't exhibit selective wettability with water contact angle (WCA) of 114.5°, the novel CoAlCe-LDHs SSM possessed superhydrophilic and underwater superoleophobic property with underwater oil contact angle (UOCA) of 158.5°. The CoAlCe-LDHs SSM was compatibly applied to the separation of oil/water mixtures with highly separation efficiency above 99.5% and ultrafast water flux of 52.2 L·m−2·s−1 under gravity. The easily-fabricated CoAlCe-LDHs SSM was qualified with recyclable, stable and anti-fouling properties, which stayed effective for the separation of oil/water mixtures under at least 30 times recycle and harsh conditions. Moreover, the bifunctional CoAlCe-LDHs SSM also showed excellent photocatalytic activity of dye degradation (with 94.2% degradation of methyl orange solution within 160 min), which can be beneficial to sewage treatment.

Influence of Fe3+ ions on the optical properties and photocatalytic ability of spin coated Fe3+ doped brookite TiO2 thin films

The spin coating process has been used to deposit pure and Fe3+ doped brookite titania films onto glass substrates. In essence, such as films annealed at 500 °C are found to be orthorhombic crystal structure with brookite phase. X-ray diffractometer measurements revealed that Fe ions are incorporated into cation sites of TiO2. The crystallite size reduces with the doping of Fe3+ ions. The scanning electron microscope images show highly uniform, crack free films and the particles size is found to be within the range of 150–200 nm. Energy-dispersive x-ray spectroscopy analysis Fe3+ doped TiO2 films confirmed good stoichiometry of chemical compositions. The Raman spectra of brookite TiO2 exhibit a very strong characteristic band at 153cm−1. The optical band gap was found to be declined from 3.08 eV to 2.54 eV with adding the Fe ions into TiO2 matrix. The EPR studies approve incorporation of Fe3+ in the crystal lattice of brookite by substituting Ti4+ and generation of defects, and Ti3+ states. Photocatalytic ability of films has been studied by degradation of methyl orange solution under illumination of visible light. The 7% Fe doped brookite film was exhibited high catalytic activity compared to other pure and doped films.

COPPER OXIDE THIN FILM SYNTHESIS, CHARACTERIZATION AND APPLICATION AS CATHODE IN PHOTOELECTROCATALYTIC CELL FOR METHYL ORANGE DEGRADATION

A copper oxide thin film was synthesized through a copper sheet annealing process that was carried out using a gas stove, furnace and 1000 W tungsten . The product and its response were measured using a and then characterized by XRD, SEM and EDX. Furthermore, the copper oxide was applied as a photocathode in a cell with Platinum (Pt) as the anode for methyl orange degradation, and the thin film annealed at 60 sec produced the highest current density. According to XRD and EDX results, copper oxide structure was dominated by Cu2O, while SEM showed the presence of a Cu2O porous surface. Methyl orange solution degradation also showed the best result for the copper oxide annealed at 60 sec and in all pH variations, while the best degradation was obtained at pH 1.

Role of Nanocrystallites of Al-Based Glasses and H2O2 in Degradation Azo Dyes.

Al-based metallic glasses have a special atomic structure and should have a unique degradation ability in azo dye solutions. The Al88Ni9Y3 (Y3), Al85Ni9Y6 (Y6) and Al82Ni9Y9 (Y9) glassy ribbons are melt spun and used in degrading methyl orange (MO) azo dye solution with adding H2O2. With increasing cY, the as-spun ribbons have an increasing GFA (glass formability) and gradually decreased the degradation rate of MO solution. TEM (transmission electron microscopy) results show that the Y3 ribbon has nano-scale crystallites, which may form the channels to transport elements to the surface for degrading the MO solution. After adding H2O2, the degradation efficiency of Al-based glasses is improved and the Y6 ribbon has formed nano-scale crystallites embedded in the amorphous matrix and it has the largest improvement in MO solution degradation. These results indicate that forming nano-scale crystallites and adding H2O2 are effective methods to improve the degradation ability of Al-based glasses in azo dye solutions.

Rapid preparation and photocatalytic properties of octahedral Cu2O@Cu powders

To improve the photocatalytic properties of Cu2O, octahedral Cu2O@Cu powders were prepared by a convenient and rapid two-step liquid phase reduction method. Glucose (C6H12O6) and thiourea dioxide (CH4N2O2S, TD for short) were used as pre-reductant and secondary-reductant separately. The microstructure and composition of the products obtained after the reduction processes were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). With the increasing of TD content, the secondary reduced products changed from solid octahedral Cu2O to octahedral Cu2O@Cu composites and finally hollow octahedral Cu2O/Cu composites. The corresponding calculated mass of Cu increased from 6.2 wt% to 80.2 wt%. The photocatalytic behavior of the reduced particles were analyzed by monitoring the degradation of methyl orange solution (MO for short) and electrochemical tests. Photocatalytic performance tests showed that octahedral Cu2O@Cu powders had an excellent photocatalytic activity. The MO degradation rate was improved from 1.4% for photocatalysts without CuNPs to 92.9% after introducing 13.4 wt% CuNPs under visible light irradiation for 60 min. This simple and rapid synthesis process allowed for the fabrication of octahedral Cu2O@Cu material with photocatalytic performance superior to pure octahedral Cu2O and hollow octahedral Cu2O/Cu materials.

Structure and photocatalytic properties of TiO2/Cu3N composite films prepared by magnetron sputtering

In this work, TiO2/Cu3N composite films were prepared by using magnetron sputtering. Results show that the optical band gap of the composite films can be effectively controlled by changing the preparation parameters, and the optical band gap of the composite films is lower than that of the TiO2 films (approximately 3.0 eV). The TiO2 in the composite films mainly appears as anatase phase, and the nano-Cu3N films prepared under the condition of r=1/4 promoted the formation of TiO2 effective electron trap on the surface of the composite films. In terms of degradation of methyl orange solution, the degradation rate of TiO2/Cu3N composite film is higher than that of pure TiO2 film, which can reach 99.2 % (using mercury lamp for 30 min). The nano-Cu3N grain inserted to TiO2 is beneficial to the conversion of Ti4+ to Ti3+, which significantly improves the photocatalytic reduction activity of the films. The TiO2/Cu3N composite films has an excellent catalytic activity and potential application prospects in wastewater treatment.

Role of maze like structure and Y2O3 on Al-based amorphous ribbon surface in MO solution degradation

The Al85Co10Y5 (Co10) amorphous ribbon exhibits an excellent degradation performance in polluted water treatment for the first time by degrading methyl orange (MO) dye. Compared with the Al85Fe10Y5 (Fe10) amorphous ribbon for degradation MO solution, the Co10 ribbon has a higher degradation efficiency, a higher TOC removal rate, a lower reaction activation energy, a stronger reusability and a higher corrosion resistance. The Co10 ribbon is not only applicable for acidic MO solution, but also has high degradation efficiency in alkaline MO solution. Compared with the spherical particles on the surface of Fe10 ribbon, the maze like structure on the surface of Co10 ribbon can increase the reaction surface area and improve the degradation efficiency of MO solution. And more O2− radicals by supplying photo catalytic Y2O3 under visible light irradiation and then enhance the degradation of MO solution. This work not only provides a new method with high efficiency and low cost for the degradation of MO solution, but also provides a new research direction for the degradation mechanism of Al-based alloys.

Photocatalytic La4Ti3O12 nanoparticles fabricated by liquid-feed flame spray pyrolysis

Hexagonal plate-like nanoparticles (NPs) of the layered perovskite La4Ti3O12 were fabricated using liquid-feed flame spray pyrolysis (LF-FSP) followed by subsequent heat-treatments. Their photocatalytic activity was evaluated using decolorization of methyl orange solutions under Uv irradiation. LF-FSP combusts metalloorganic precursor aerosols to produce mixtures of cubic simple perovskite (ABO3) phase and lanthanum oxycarbonate (La2O4·846C0.846) phase with very low agglomeration and average particle sizes (APSs) of 23 nm (as-produced NPs). Rietveld refinement of synchrotron XRD powder patterns verified that the simple perovskite in the as-produced NPs is LaTiO3 (originally cubic Pm-3m-type space group) and heat-treating gives NPs of the trigonal layered perovskite La4Ti3O12 (R-3-type space group). La4Ti3O12 NPs heat-treated at 1100 °C/3-6h/air exhibits hexagonal plate-like morphology and high crystallinity offering enhanced photocatalytic degradation of methyl orange solutions compared to the as-produced NPs. The LF-FSP approach to obtaining layered perovskite La4Ti3O12 NPs provides a simple route to photocatalytic materials in reasonable quantities.

Construction of hierarchical square biscuit-shape BiOBr photocatalyst with enhanced visible-light-response photocatalytic activities

Herein, we first explore an efficient solvothermal method to fabricate hierarchical square biscuit-like BiOBr architecture (SBBA), and further utilize it as a visible-light-responsive photocatalyst. The photocatalytic performance of the resultant SBBA is comprehensively evaluated by photocatalytic degradation of methyl orange solution as a model wastewater under the visible light irradiation. The SBBA photocatalyst with a band gap of ∼2.56 eV exhibits remarkable photocatalytic activities in terms of degradation efficiency and reproducibility. More importantly, a plausible electron transfer and involved degradation mechanism are put forward. The excellent photocatalytic activities consolidate it as a promising photocatalyst in practical wastewater treatment.

Degradation of methyl orange by photo assisted fenton reaction using Indonesian bauxite as catalyst

Photo fenton catalyst is an effective and environmentally friendly catalyst for degrade organic pollutants. Novel photo fenton catalyst was successfully prepared from Indonesia bauxite was used as a catalyst for degradation of methyl orange solution. This catalyst is more cheaper than Nafion-based catalyst and more greener than other synthesized catalysts. It is easily prepared from Indonesian natural resources. X-ray diffraction measurements provide structure and mineral composition of bauxite, while XRF provides information on the composition of Fe by 18% by weight of bauxite mass. The presence of large amounts of Fe in bauxite acts as a catalyst in the decomposition of metyl orange. Testing of photo fenton activity to decompose metyl orange showed that Indonesian bauxite had high catalytic activity, was able to decompose 99.4% metyl orange within 40 minutes on irradiation using an 9Watt UVC radiation source.

Green preparation of Ag-ZnO-rGO nanoparticles for efficient adsorption and photodegradation activity

To improve the photocatalytic performance of ZnO nanoparticles, based on the collective effect as electron sink of Ag and perfect two-dimensional (2-D) feature of graphene, Ag-ZnO-rGO nanoparticles were prepared by polyvinyl alcohol assisted freeze-drying and subsequent hydrothermal reduction method. Through photocatalytic degradation of methyl orange solution under UV irradiation, all as-prepared samples were assessed and compared with those of published works. The surface morphology, microstructure and optical property of materials were systematically studied by XRD, XPS, SEM, TEM and DRS, respectively. XPS and Raman spectra results confirmed that GO has successfully been reduced to rGO; SEM and TEM characterizations manifested that Ag-ZnO NPs were uniformly distributed in rGO with two-dimensional sheets structure; DRS characterization and Kubelka-Munk formula calculation illustrated that Ag-ZnO-rGO exhibited the smallest band gap and the best optical absorption performance. Moreover, the photocatalytic degradation results indicated that Ag-ZnO-rGO NPs combine the advantages of graphene and Ag which not only has significant adsorption but also maintains high photoreactivity.

Preparation and characterization of SnO2−x/GO composite photocatalyst and its visible light photocatalytic activity for self-cleaning cotton fabrics

Sn2+ self-doped SnO2 (SnO2−x) nanocrystal and SnO2−x/graphene oxide (SnO2−x/GO) composite photocatalyst were prepared by hydrothermal method and characterized by transmission electron microscope, energy dispersive X-ray, X-ray diffraction, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy, photocurrent and photocatalytic activity. SnO2−x/GO was hydroxylated with 3,4-dihydroxy phenyl acetic acid to obtain the carboxylated SnO2−x/GO. Cotton fabrics were cationically modified by 3-chloro-2 hydroxy propyltrim ethylammonium chloride and then finished with the carboxylated SnO2−x/GO composite photocatalyst. Cotton fabrics were characterized by SEM, XPS and self-cleaning activity. Photocatalytic activity of SnO2−x/GO composite photocatalyst and self-cleaning activity of cotton fabrics were evaluated by photocatalytic degradation of methyl orange solution and methylene blue solution under the visible light, respectively. Photocatalytic activity of SnO2−x/GO composite photocatalyst firstly increased and then decreased with the increasing molar ratio of Sn4+/Sn, and the GO concentration in SnO2−x/GO. The optimal molar ratio of Sn4+/Sn and GO concentration were 1:4 and 5%, respectively. The SnO2−x/GO finished cotton fabrics exhibited highly efficient and durable self-cleaning activity. In addition, the mechanism for SnO2−x/GO photocatalytic activity, and the mechanism and possible reactions for the chemically binding of SnO2−x/GO composite photocatalyst with cotton fabrics were proposed.

High yield synthesis of homogeneous boron doping C3N4 nanocrystals with enhanced photocatalytic property

Carbon nitride (C3N4) has attracted widespread attention in the photocatalysis field for its stability, facile preparation from low-cost materials, and outstanding visible-light activity. Exploring novel synthesis or modification approaches of C3N4 with excellent photocatalytic property is still a research hotspot in this area. Herein we report a high-yield synthesis of C3N4 and boron-doped C3N4 using the mixed salts KCl-NaCl-LiCl as solvent. Compared with C3N4 sample prepared by the traditional solid-state reaction method, the sample by the molten-salt process showed much better photocatalytic activity for the degradation of methyl orange solution under visible light, which should be originated from high crystallinity and large surface areas as demonstrated by XRD, TEM and BET results. Furthermore, the photocatalytic activity of the molten-salt prepared C3N4 samples was regulated by boron doping, and the best photocatalytic performance was found at the boron content of 0.5%. Moreover, the photoluminescence properties of the samples were also investigated. The relationship between the photoluminescent and photocatalytic performances of the samples were compared and discussed. We believe the synthetic approach reported here provides a new strategy toward the homogeneous doped C3N4-based materials.

The role of microstructure in piezocatalytic degradation of organic dye pollutants in wastewater

Piezoelectrically-induced catalytic effect, piezocatalysis, is considered with a great potential in addressing the environmental issues. In this work, BaTiO3 nanowires (BTO NWs) were prepared by combining the sol-gel-based electrospinning technique and post calcination process. Their microstructure characteristics, including crystal structure, crystalline size, surface area and dimension, were effectively adjusted by altering the calcination temperature, calcination time or precursor concentration. And the roles of these microstructure characteristics in the piezocatalytic activity were thoroughly investigated by degradation of methyl orange solution under ultrasonic vibration. Results indicated that the crystal structure and surface area play an important role in piezocatalytic activity of BTO NWs. Moreover, experimental results indicated that BTO NWs with smaller diameter or being composed of smaller size crystallites contributes to better piezocatalytic performance. Our present work gives a clear understanding of the role of microstructure in piezocatalysis and provides a way to develop high performance piezocatalysts.

Designing visible-light-driven photocatalyst of Ag3PO4/CeO2 for enhanced photocatalytic activity under low light irradiation

In this study the preparation and the evaluation of Ag3PO4/CeO2 composites as visible-light-driven photocatalyst were reported. The composites, with different Ag3PO4:CeO2 molar ratio, were prepared via chemical precipitation and their photocatalytic performance were investigated by photodegradation of methyl orange solution (MO) under low intensity (23 W) visible light irradiation. Characterization analyses showed that the Ag3PO4 particles were irregular spherical-shaped and were well-distributed on the surface of CeO2. The photocatalytic activity of the composite was higher than that of Ag3PO4 and CeO2. The composite with 1:2.5 molar ratio exhibited the highest photocatalytic activity with degradation rate of 0.338 min−1 and 92% degradation efficiency. Besides, the composite can be used up to eight cycles without any regeneration process. Through radical scavenger experiments, the photogenerated holes (h+) and the $$ \cdot {\text{O}}_{2}^{ - }$$ radical were the active species for degradation of MO.