Catalyst For Degradation Of Methylene Blue Research Articles

Quick methylene blue dye elimination via SDS-Ag nanoparticles catalysts

Methylene blue dye, being toxic, carcinogenic and non-biodegradable, poses a serious threat for human health and environmental safety. The effective and time-saving removal of such industrial dye necessitates the use of innovative technologies such as silver nanoparticle-based catalysis. Utilizing a pulsed Nd:YAG laser operating at the second harmonic generation of 532 nm with 2.6 J energy per pulse and 10 ns pulse duration, Ag nanoparticles were synthesized via an eco-friendly method with sodium dodecyl sulphate (SDS) as a capping agent. Different exposure times (15, 30, and 45 min) resulted in varying nanoparticle sizes. Characterization was achieved through UV–Vis absorption spectroscopy, scanning electron microscopy (SEM) imaging, and energy dispersive X-ray (EDX). Lorentzian fitting was used to model nanoparticle size, aligning well with SEM results. Mie’s theory was applied to evaluate the absorption, scattering, and extinction cross-sectional area spectra. EDX revealed increasing Ag and carbon content with exposure time. The SDS-caped AgNPs nanoparticles were tested as catalyst for methylene blue degradation, achieving up to 92.5% removal in just 12 min with a rate constant of 0.2626 min−1, suggesting efficient and time-saving catalyst compared to previously reported Ag-based nanocatalysts.

Commelina erecta, L. biomass‑silver nanoparticle composite as a heterogeneous catalyst for methylene blue degradation

Commelina erecta, L. biomass‑silver nanoparticle composite as a heterogeneous catalyst for methylene blue degradation

Effect of mass ratio on rGO/TiO2 composite as catalyst for methylene blue degradation under UV irradiation

Adsorption and photocatalytic are commonly used methods for the removal of dye contained in industrial wastewater. Therefore, this study aimed to combine reduced Graphene Oxide (rGO) with Titanium Oxide (TiO2) through various compositions using the hydrothermal method to obtain a catalyst of rGO/TiO2 nanocomposites for the removal of contaminants from wastewater. The synthesized rGO/TiO2 nanocomposites were mixed with methylene blue (MB) to reduce their content in water under dark conditions and UV light irradiation. The change of the optical properties of MB under both conditions was also examined, where a decrease in absorbance was observed. Under UV light irradiation, the maximum wavelength [Formula: see text] of MB shifted from 664[Formula: see text]nm to 649[Formula: see text]nm but remained constant at 664[Formula: see text]nm in dark conditions. The results of optical characterizations confirmed that the adsorption of MB by rGO/TiO2 nanocomposites under dark conditions did not change the MB structure. However, a significant degradation was observed with photocatalytic process under UV light irradiation. Nanocomposites rGO/TiO2 with rGO 60% and TiO2 40% (GT40) have better performance in reducing MB under UV light irradiation.

Photocatalytic degradation of methylene blue dye using biogenic copper oxide nanoparticles and its degradation pathway analysis

In order to remove the toxic organic dyes from the environment, biogenic inorganic semiconductor nanoparticle based photocatalyst has drawn attention due to its low cost, simplicity, eco-friendliness, high efficiency and ease of process. Herein, Copper oxide nanoparticles (CuO NPs) were prepared by using Syzygium Cumini seed extract as reducing as well capping agent. The formed CuO NPs were characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), B.E.T isotherm, UV–Visible spectroscopy, Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS) analysis. The CuO NP’s photocatalytic activities have been analyzed with methylene blue (MB) degradation. The effect of the catalyst for MB degradation has been optimized at various catalyst amount, dye concentration and pH environments. The results showed that, the CuO NPs can effectively degrade 97 % of MB in 60 min, following pseudo first order kinetics, while the rate constant was found to be 0.06 min−1. The present catalyst material showed 95 % MB degradation with similar morphology of freshly prepared catalyst even after five consecuetive reuse cycles and worked effectively over a wide pH range. The degradation pathway of MB was studied through the HR-MS technique.

Single-step solvothermal synthesis of sepiolite-CoFe2O4 nanocomposite as a highly efficient heterogeneous catalyst for photo Fenton-like reaction

In present research, a novel sepiolite-CoFe2O4 (Sep-CoFe2O4) catalyst was prepared using a facile solvothermal strategy. The structure, morphology, and photoelectric properties of the synthesized catalyst were explored by the SEM, TEM, VSM, DRS, XRD, XPS and EDX methods. The results showed that CoFe2O4 particles had a spherical shape and was successfully deposited on the fibrous structure of Sep clay. The prepared Sep-CoFe2O4 catalyst was employed in heterogeneous photo-Fenton reaction for methylene blue (MB) degradation. Sep effectively prevented the aggregation of CoFe2O4 and clearly enhanced the efficiency of the heterogeneous catalyst for degradation of MB under visible light irradiation. In photo Fenton-like reaction, complete degradation of MB (C = 10 ppm) was achieved in 150 min at mild pH value. The reusability experiments showed that the suggested catalyst can be reused after five successive cycles. Besides, a possible degradation mechanism using the photo Fenton-like system was presumed. Accounting for the high catalytic capability, low cost, as well as good chemical stability, the Sep-CoFe2O4 has great potential working as a heterogeneous photo-Fenton catalyst for degradation of organic contaminants.

Preparation of Cobalt and Nitrogen‐Doped Porous Carbon Composite Catalysts From ZIF‐9 and Their Outstanding Fenton‐like Catalytic Properties Towards Methylene Blue

AbstractTo activate peroxymonosulfate (PMS) and degrade methylene blue (MB), cobalt and nitrogen‐doped porous carbon composite catalysts were prepared through pyrolysing zeolitic imidazolate framework ZIF‐9 and dicyandiamide (DCDA) at 700–900 °C with various mass ratios. Powder X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and Brunauer‐Emmett‐Teller results showed that Co, porous carbon and carbon nanotubes (CNTs) co‐existed in the catalyst prepared at 800 °C with a ZIF‐9/DCDA ratio of 1 : 3. Thermogravimetric analysis suggested that CNT@ZIF‐800 had a higher ratio of graphitic to turbostratic carbon than CNT@ZIF‐700. It had degraded 94.8 % MB within 30 min, which was about 1.9 times faster than its counterpart C‐ZIF‐800. It also showed faster degradation rates towards Congo red (98.5 %, 5 min) and slower rates towards rhodamine B (90.7 %, 30 min) than MB. Furthermore, XPS revealed that it had 14.5 % more Co−Nx/pyridinic‐N active sites than C‐ZIF‐800. EPR suggested that 1O2 might be the primary catalytic species whereas the SO4−⋅ and ⋅OH the secondary ones. The formation mechanism of such active species might be originated from the synergistic activation of PMS by CNTs, Co−Nx/pyridinic‐N and abundant Co sites in the CNT@ZIF‐800. This work not only provided efficient Fenton‐like catalysts for MB degradation, but also clarified the catalytic mechanism.

Adsorption of Cu2+ on Fe/SUZ-4 and its application as catalyst for methylene blue degradation

The effect of KOH treatment on the crystal structure, morphology, and adsorption/catalytic performance of SUZ-4-based material was investigated by XRD, SEM, FT-IR and BET characterizations. Based on the catalytic performance, the concentration of the KOH solution was set at 3.0 mol/L. The influence of pH, temperature, contact time, adsorbent dosage, and initial concentration of Cu2+ on the adsorption capacity of Fe/S3 was studied. The adsorption process was better fitted by Langmuir and pseudo-second-order models based on the kinetic and isotherm data. The obtained Cu–Fe/S3 after adsorption was used as catalyst in the MB degradation instead of discarding. The catalyst exhibited MB removal rate of 81.5% from the 100.0 mL aqueous 150 mg/L MB solution with 0.1 g adsorbent in the presence of 0.5 mL H2O2 at pH = 7. The mechanism for the reaction has been proposed, in which the redox cycle of Fe3+/Fe2+ and Cu2+/Cu+ pairs was important for the generation of hydroxyl radicals in the Cu–Fe/S3/H2O2 system.

Utilization of camellia oleifera shell for production of valuable products by pyrolysis

Camellia oleifera shell is used as the feedstock to prepare the valuable products by pyrolysis using microwave heating at 400-800 °C. The yield of pyrolysis product is influenced by pyrolysis temperature, which indicates that high pyrolysis temperature promotes to generate bio-gas and restrains the production of biochar. However, pyrolysis temperature little influences the yield of bio-oil. The main compound of bio-oil is phenols, hydrocarbons, ketones, aldehydes and furans, respectively. While, bio-oil produced at 600 °C has as high as 78 % of phenols, which has potential application in chemical industries. The pyrolysis temperature has significantly influenced the composition and heating value of bio-gas. The maximum heating value of bio-gas is 12.44 MJ/Nm3, which is achieved at 600 °C. The physiochemical properties of biochar are also influenced by pyrolysis temperature. Biochar could be used as an adsorbent to adsorb Ag+ from aqueous solution, which is formed the value-added ABiochar composite by reduction. The adsorption and reduction process of Ag+ are investigated. While, ABiochar composite can be used as the catalyst for methylene blue degradation. ABiochar composite can be also used in the lithium ion battery cathode material for energy storage.

Synthesis and Characterization of 2D-WS2 Incorporated Polyaniline Nanocomposites as Photo Catalyst for Methylene Blue Degradation.

2D-WS2 incorporated polyaniline nanocomposites (WS2-PANI) with varying WS2 loadings were synthesized by a facile in situ oxidative polymerization technique which effectively promoted photocatalytic waste-water remediation using methylene blue (MB) as the probe molecules. The physicochemical properties of WS2-PANI (1–5) nanocomposites were investigated using multifarious techniques such as FT-IR, XRD, BET surface area, TGA, FESEM, and HRTEM. An electron microscopy analysis that was performed using HRTEM analysis confirm the layered structure of WS2 with periodic planes (100) separated by 0.27 nm. The photocatalytic performance of the WS2-PANI (1–5) for MB degradation performed under UV photo irradiation clearly showed that 2 wt.% WS2-PANI outperformed other variants with 93% degradation MB within 90 min. Furthermore, the catalytic material was reusable for five cycles without a significant loss of the catalytic performance.

Calcined Aluminum Sludge as a Heterogeneous Fenton-Like Catalyst for Methylene Blue Degradation by Three-Dimensional Electrochemical System

Calcined Aluminum Sludge as a Heterogeneous Fenton-Like Catalyst for Methylene Blue Degradation by Three-Dimensional Electrochemical System

Comparative study of methylene blue adsorption using alkali-activated pumice from Bali and Banten

This study presents the comparison of methylene blue (MB) adsorption using alkali-activated pumice from Bali (A-P1) and Banten (A-P2). Pumice samples were activated under alkaline solution and followed by simple hydrothermal treatment in a polypropylene bottle at 100 °C for 24 hours. The X-ray diffraction (XRD) patterns showed that both treated pumices have different peak characteristics, where only A-P1 was dominated by the mineral phase of GIS-NaP1 zeolite. The change of amorphous to zeolite phases increased negative sides and caused A-P1 to have a higher adsorption capacity than A-P2. Based on the adsorption data of AP1 and AP2, the Langmuir isotherm model shows a better fit with high correlation values (R2) compared to the Freundlich model. This means the interaction between the treated pumice and MB followed the assumption of monolayer coverage on homogeneous surfaces, in which the maximum values of MB adsorption were found to be 51.546 mg/g for A-P1 and 27.027 mg/g for A-P2. In addition, A-P1 and A-P2 were also potentially used as heterogeneous catalysts for MB degradation through Fenton-like process due to the presence of iron oxide contents.

Constructing mesoporous g-C3N4/ZnO nanosheets catalyst for enhanced visible-light driven photocatalytic activity

Novel mesoporous graphitic carbon nitride (g-C3N4) was synthesized via one-step thermal condensation of ethyl cellulose (EC) and urea mixture. Morphology, crystal structure and charge carrier lifetime of the composites were controlled by tuning the amount of EC. The optimized 5 wt% EC/g-C3N4 (OEC/g-C3N4), which showed the highest surface area and longest carrier lifetime, were facilely incorporated into the ZnO nanosheet by the hydrothermal method as catalyst for methylene blue degradation under visible-light irradiation. The optimized photocatalytic activity of OEC/g-C3N4/ZnO nanosheets at a weight ratio of 3% under visible-light irradiation is almost 8.5 times higher than that of ZnO nanosheets. This enhancement in performance is mainly attributed to OEC/g-C3N4 incorporation, which broadens the light absorption and facilitates the separation and transfer of photogenerated electron–hole pairs at the interface. In addition, this method is expected to be extended to other EC/g-C3N4 loaded materials.

Nanosized Zincated Hydroxyapatite as a Promising Heterogeneous Photo-Fenton-Like Catalyst for Methylene Blue Degradation

This study is devoted to synthesis of nanosized zincated hydroxyapatite (Zn-HA) and its utilization as a heterogeneous photo-Fenton-like catalyst for degradation of methylene blue (MB) in aqueous solution. The prepared catalyst was characterized by various techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray, and Fourier transform infrared spectroscopy. The catalytic activity of Zn-HA towards MB and the effects of various experimental factors such as pH, zinc substitution degrees, initial MB concentration, and H2O2 dosage were studied in detail. The results showed that the zinc substitution degree of 0.4 is optimal to get the highest degradation efficiency under conditions of pH = 10, H2O2 dosage of 0.05 M, and MB concentration of 30 mg/L for a contact time of 120 min. The degradation mechanism was proposed and discussed thoroughly. Besides, the ability of long-term use for the synthesized catalyst was also evaluated.

The enhanced catalytic activities of octahedral layer birnessite-type manganese oxide synthesized via precipitation method for the degradation of methylene blue

The catalytic activities of the octahedral layer birnessite-type manganese oxides for the degradation of methylene blue (MB) dye have been studied. The oxide catalysts were prepared via a facile precipitation method using the reaction between KMnO4 (oxidant) and citric acid or oxalic acid (reductant), where the acid is added dropwise into KMnO4 until certain volume achieved to generate a brownish black precipitate. The solid product was treated with either calcination or without calcination process, respectively. The samples without calcination display poor crystallinity with low intensity and broad peak and are identified as birnessite-type manganese oxides. The calcination, however, led to the formation of the highly crystalline birnessite materials. The birnessite catalysts synthesized by the different reductants displayed different crystallinity, morphology, average oxidation state (AOS) of manganese, zero-point charge pH (pHzpc) and particle size that affect their catalytic activities. The results indicated that the activities of birnessite-type manganese oxide catalysts for MB degradation correlated with the nature of catalysts. The citric acid-prepared manganese oxide catalyst (CAC) showed slight higher crystalline phase compared with the oxalic acid-prepared manganese oxide catalyst (OAC). The data from AOS of manganese suggested that the CAC catalysts have a lower value of AOS of manganese than OAC catalysts, indicating more defects due to the presence of more oxygen vacancy or more Mn3+ content. The smaller particle size and AOS of manganese for CAC catalysts are also considered to be responsible for their higher catalytic activities for MB degradation. The birnessite-type manganese oxide catalysts prepared without calcinations also showed much enhanced catalytic activities for MB degradation.

Synthesis of magnetic Cu/CuFe2O4 nanocomposite as a highly efficient Fenton-like catalyst for methylene blue degradation

A magnetic Cu/CuFe2O4 nanocomposite was synthesized by a facile one-pot solvothermal method and characterized as an excellent Fenton-like catalyst for methylene blue (MB) degradation. The content of zero-valent copper (Cu0) in Cu/CuFe2O4 composite could be simply controlled by changing the dosage of sodium acetate in the synthetic process, and the Fenton-like catalytic performance of Cu/CuFe2O4 composite enhanced with increasing the Cu0 content. In the presence of H2O2 (15 mM), the as-synthesized 3-Cu/CuFe2O4 nanocomposite could remove 99% of MB (50 mg/L) after only 4 min at pH 2.50, greatly higher than that of pure CuFe2O4 and Cu0 under the same condition. The enhancement activity of Cu/CuFe2O4 nanocomposite was due to the synergistic effect between Cu0 and CuFe2O4. The radical capture experiments and coumarin fluorescent probe technique confirmed that MB was degraded mainly by the attack of OH· radicals in Cu/CuFe2O4–H2O2 system.

Synthesis of a MnO2/Fe3O4/diatomite nanocomposite as an efficient heterogeneous Fenton-like catalyst for methylene blue degradation.

Heterogeneous Fenton-like catalysts with the activation of peroxymonosulfate (PMS), which offer the advantages of fast reaction rate, wide functional pH range and cost efficiency, have attracted great interest in wastewater treatment. In this study, a novel magnetic MnO2/Fe3O4/diatomite nanocomposite is synthesized and then used as heterogeneous Fenton-like catalyst to degrade the organic pollutant methylene blue (MB) with the activation of PMS. The characterization results show that the Fe3O4 nanoparticles and nanoflower-like MnO2 are evenly distributed layer-by-layer on the surface of diatomite, which can be readily magnetically separated from the solution. The as-prepared catalyst, compared with other Fenton-like catalysts, shows a superb MB degradation rate of nearly 100% in 45 min in the pH range of 4 to 8 and temperature range of 25 to 55 °C. Moreover, the nanocomposite shows a good mineralization rate of about 60% in 60 min and great recyclability with a recycle efficiency of 86.78% after five runs for MB. The probable mechanism of this catalytic system is also proposed as a synergistic effect between MnO2 and Fe3O4.

Photocatalytic Behavior of Strontium Aluminates Co-Doped with Europium and Dysprosium Synthesized by Hydrothermal Reaction in Degradation of Methylene Blue

Strontium aluminates co-doped with europium and dysprosium were prepared by a hydrothermal reaction through a sintering process at lower temperatures. The physicochemical properties of the strontium aluminates co-doped with europium and dysprosium were characterized and compared with those of strontium aluminates prepared by a sol–gel method. The photocatalytic properties of the strontium aluminates co-doped with europium and dysprosium were evaluated through the photocatalytic decomposition of methylene blue dye. The strontium aluminates co-doped with europium and dysprosium prepared by the hydrothermal reaction exhibited good phosphorescence and photocatalytic activities that were similar to those prepared by the sol–gel method. The photocatalytic activity of these catalysts for methylene blue degradation was higher than that of the titanium dioxide (TiO2) photocatalyst.

New insight into the microstructure of natural calcined laterites and their performance as heterogeneous Fenton catalyst for methylene blue degradation

In this work, natural laterites from Burkina Faso were calcined at different temperatures in the range 400–800 °C. XRD, EDS, N2 adsorption manometry and TGA–DSC analyses together with a thorough analysis of available literature data, support that the laterite sample consists mainly of goethite and hematite embedded in a framework of kaolinite and quartz with different interaction extents. During calcination up to 400 °C, the kaolinite structure is partially destroyed due to the loss of structural water and the goethite phase previously in association with the kaolinite lattice transforms into free hematite crystallites, resulting in a drop of the surface area of the composite material. At 600 °C, the kaolinite lattice is further deshydroxylated leading to an amorphous metakaolin matrix containing mainly surface hematite nanophases. Despite a substantial reduction of the surface area due to the calcination-induced shrinkage of alumino-silicate framework, the laterite calcined at 600 °C exhibits the highest performance in the methylene blue (MB) degradation by the Fenton process with a degradation percentage of 99% after 100 min of treatment at room temperature. The effects of solution pH, H2O2 concentration, initial MB concentration and catalyst dosage were investigated. A slight but significant visible-light-induced removal enhancement effect suggested a visible-light photocatalytic activity of the hematite phase. This calcined laterite demonstrates a strong catalytic stability over several utilizations therefore is worth to be seriously considered in the design of sustainable and readily affordable wastewater treatment solutions in developing tropical countries.

Fabrication of Macroporous Co<sub>3</sub>O<sub>4</sub>–MgO Composite Catalysts for Methylene Blue Degradation Using Oxone as an Oxidant

Fabrication of Macroporous Co<sub>3</sub>O<sub>4</sub>–MgO Composite Catalysts for Methylene Blue Degradation Using Oxone as an Oxidant

Consecutive Reaction to Construct Hierarchical Nanocrystalline CuS "Branch" with Tunable Catalysis Properties.

New CuS nanocrystals with a 3D hierarchical branched structure are successfully synthesized through in situ consecutive reaction method with copper foam as template. The formation mechanism of the 3D hierarchical branched structure obtained from the secondary reaction is investigated by adjusting the reaction time. The morphology of CuS nanosheet arrays with the 3D hierarchical branched structure is changed through Cu2+ exchange. In this method, the copper foam reacted completely, and the as-synthesized CuS@Cu9S5 nanocrystals are firmly grown on the surface of the 3D framework. This tunable morphology significantly influence the physical and chemical properties, particularly catalytic performance, of the materials. The as-obtained material of Cu@CuS-2 with the 3D hierarchical branched structure as catalyst for methylene blue degradation exhibits good catalytic performance than that of the material of Cu@CuS with 2D nanosheets in dark environment. Furthermore, the cation exchange between Cu and Cu2+ indicates that Cu2+ in wastewater could be absorbed by Cu@CuS-2 with the 3D hierarchical branched structure. The exchanged resultant of CuS@Cu9S5 retains its capability to degrade organic dyes. This in situ consecutive reaction method may have a significant impact on controlling the crystal growth direction of inorganic material.