Malachite Green Degradation Research Articles

Cellulose nanocrystals doped silver nanoparticles immobilized agar gum for efficient photocatalytic degradation of malachite green

The present study involves the synthesis of green functional material based on the silver nanoparticle (Ag NPs) doped cellulose nanocrystals (CNC) immobilized agar gum (AA) biopolymer using chemical coprecipitation method. The stabilization of Ag NPs in cellulose matrix and functionalization of the synthesized material through agar gum was analyzed using various spectroscopic techniques such as Fourier Transform Infrared (FTIR), Scanning electron microscope (SEM), Energy X-Ray diffraction (EDX), Photoelectron X-ray (XPS), Transmission electron microscope (TEM), Selected area energy diffraction (SAED) and ultraviolet visible (UV–Vis) spectroscopy. The XRD results suggested that the synthesized AA-CNC@Ag BNC material is composed of 47 % crystalline and 53 % amorphous nature having distorted hexagonal structure due to capping of Ag NPs by amorphous biopolymer matrix. The Debye-Scherer crystallite sized was calculated as 18 nm which is found in close agreement with TEM analysis (19 nm). The SAED yellow fringes simulates the miller indices values with XRD patterns and supported the surface functionalization of Ag NPs by biopolymer blend of AA-CNC. The XPS data supported the presence of Ag0 as indexed by Ag3d orbital corresponding to Ag3d3/2 at 372.6 eV and Ag3d5/2 at 366.6 eV. The surface morphological results revealed a flaky surface of the resultant material having well distributed Ag NPs in the matrix. The EDX and atomic concentration results given by XPS supported the presence if C, O and Ag in the bionanocomposite material. The UV–Vis results suggested that the material is both UV and visible light active having multiple SPR effects with anisotropy. The material was explored as a photocatalyst for remediation of wastewater contaminated by malachite green (MG) using advance oxidation process (AOP). Photocatalytic experiments were performed in order to optimize various reaction parameters such as irradiation time, pH, catalyst dose and MG concentration. The obtained results showed that almost 98.85 % of MG was degraded by using 20 mg of catalyst at pH 9 for 60 min of irradiation. The trapping experiments revealed that •O2− radicals played primary role in MG degradation. This study will provide new possible strategies for the remediation of wastewater contaminated by MG.

Green synthesis of novel YMnO3-doped TiO2 for enhanced visible-light- driven photocatalytic degradation of malachite green

Recently, new methods of utilizing chemistry materials to overcome environmental issues worldwide, for instance, water purification have widely evolved since it is well-aligned with the sustainable development goals 6: clean water and sanitation. These issues have become a vital research topic for researchers in the last decade, particularly, the use of green photocatalyst due to the limitation of renewable resources. Herein, we report the modification of titanium dioxide with yttrium manganite (TiO2/YMnO3) by a novel high-speed stirring technique in n-hexane-water utilizing Annona muricata L. leaf extracts (AMLE). The YMnO3 incorporation in the presence of TiO2 was introduced to accelerate the photocatalytic performance for the degradation of malachite green in aqueous media. TiO2 modification with YMnO3 presented a drastic decline of bandgap energy from 3.34 to 2.38 eV and the highest rate constant (kapp) of 2.275 × 10-2 min-1. Surprisingly, TiO2/YMnO3 exhibited an extraordinary photodegradation efficiency of 95.34%, which was 1.9-fold higher than that of TiO2 under visible light illumination. The enhanced photocatalytic activity is ascribed to the formation of a TiO2/YMnO3 heterojunction, narrower optical band gap, excellent charge carrier separation. H+ and .O2– were the major scavenger species that play a significant role in the photodegradation of malachite green. Additionally, TiO2/YMnO3 shows outstanding stability over five cycles of photocatalytic reaction without significant loss of its effectiveness. This work presents a recent understanding of the green construction of a novel TiO2-based YMnO3 photocatalyst with excellent efficiency in the visible region for environmental technology application in water purification specifically in degrading organic dyes.

Zn/Fe bimetallic modified Spartina alterniflora-derived biochar heterostructure with superior catalytic performance for the degradation of malachite green

In this study, the synchronous magnetized carbonization method was utilized for preparing photocatalysis ZnO-Fe@SC heterostructure, which exhibited degradation efficiency 99.14% (60 min) for malachite green (200 mg/L) and could still maintain good performance after 5 cycles. The prepared ZnO-Fe@SC was analyzed using UV–Vis DRS, PL, SEM, TEM, BET, FTIR, XPS and VSM, and LC–MS for degradation products. The results indicate that photocatalyst has favorable magnetic properties, chemical stability and low charge carriers (e−/h+) recombination rate. The modification of bimetals enables the composite photocatalyst to enhance the intensity of photogenerated electron transition. Moreover, quenching experiment revealed that the photo-generated holes (h+) and superoxide radicals (·O2−) were the dominant active species during the photocatalytic process, which degraded malachite green into small molecules by demethylation, deamination, ring-opening reactions as deducted from LC–MS analysis. ZnO-Fe@SC was prepared using a green, safe, low cost and operable synthetic method, which has a broad market potential in the field of environmental remediation.Graphical

Sargassum natans I Algae: An Alternative for a Greener Approach for the Synthesis of ZnO Nanostructures with Biological and Environmental Applications.

In this work, the influence of the Sargassum natans I alga extract on the morphological characteristics of synthesized ZnO nanostructures, with potential biological and environmental applications, was evaluated. For this purpose, different ZnO geometries were synthesized by the co-precipitation method, using Sargassum natans I alga extract as stabilizing agent. Four extract volumes (5, 10, 20, and 50 mL) were evaluated to obtain the different nanostructures. Moreover, a sample by chemical synthesis, without the addition of extract, was prepared. The characterization of the ZnO samples was carried out by UV-Vis spectroscopy, FT-IR spectroscopy, X-ray diffraction, and scanning electron microscopy. The results showed that the Sargassum alga extract has a fundamental role in the stabilization process of the ZnO nanoparticles. In addition, it was shown that the increase in the Sargassum alga extract leads to preferential growth and arrangement, obtaining well-defined shaped particles. ZnO nanostructures demonstrated significant anti-inflammatory response by the in vitro egg albumin protein denaturation for biological purposes. Additionally, quantitative antibacterial analysis (AA) showed that the ZnO nanostructures synthesized with 10 and 20 mL of extract demonstrated high AA against Gram (+) S. aureus and moderate AA behavior against Gram (-) P. aeruginosa, depending on the ZnO arrangement induced by the Sargassum natans I alga extract and the nanoparticles' concentration (ca. 3200 µg/mL). Additionally, ZnO samples were evaluated as photocatalytic materials through the degradation of organic dyes. Complete degradation of both methyl violet and malachite green were achieved using the ZnO sample synthesized with 50 mL of extract. In all cases, the well-defined morphology of ZnO induced by the Sargassum natans I alga extract played a key role in the combined biological/environmental performance.

Effective Malachite Green Degradation over the Noble Metal-Doped and MOF-Coupled CsSnBr3 Nanocomposite Catalyst

Environmental protection laws require effective and green solutions to tackle water and air pollution issues. For this purpose, perovskite photocatalytic materials have proven to be a promising solution. In this study, CsSnBr3 perovskite, coupled with ZIF-67 and decorated with noble metal Au, was shown to effectively enhance the charge separation and increase the light-absorbing capacity, and thus make the photocatalytic reaction more efficient by surface plasmon resonance. Characterization results from XRD, FTIR, and UV-visible diffuse reflectance spectroscopy indicated that a mixture of cubic and tetragonal crystalline phases was found in the prepared catalyst material. XPS also revealed that in the presence of two oxidation states for tin (Sn), the Au 4f XPS peaks of Au NPs coincided with those retained in colloidal Au particles. Using malachite green as a model compound, organic pollutant photocatalytic degradation tests proved that CsSnBr3 generated good photocatalytic activity for aromatic pollutant degradation. In this research, the synthesized 4Au-7ZIF-CsSnBr3 catalyst yielded an MG degradation rate twice as high as the unpromoted CsPbBr3.

Synthesis and Characterization of Fe3O4 and Au- co-doped Fe3O4

Co-precipitation was used to synthesis Au/Fe3O4 nano-composites different Au contents, (XRD) , (SEM) were used to analyze the nano-composites' microstructure and phase (EDX) , (XPS) were used to confirm the compositions of the powders. UV-Vis spectroscopy utilized to examine the particles' band gaps. Malachite green(MG) degradation was examined using the photocatalytic property of the nanocomposites, also the powders with 0.5 mol of Au exhibit the highest photocatalytic degradation efficiency. The reaction conditions for Au(0.5)/Fe3O4 were also evaluated.

Sonochemical reassembling of Acacia nilotica bark extract mediated Mg doped WO3@g-C3N4 ternary nanocomposite: A robust nanophotocatalyst

One of the most significant environmental issues of the modern era is malachite green dye wastewater due to its high toxicity, susceptibility for mutagenicity, and carcinogenicity. In order to tackle this problem, we prepared Z-scheme type Mg-doped WO3 supported onto g-C3N4 ternary photocatalyst by sonochemical intercalating Mg into WO3@g-C3N4 binary composite in the Acacia nilotica bark extract medium. X-ray diffraction, SEM, EDS, HR-TEM, photoluminescence, and BET surface area analysis were used to explore the structural, morphological and surface characteristics. The findings indicated that the formation of highly crystalline with aggregated lump-based flakiness and various nano-sized crystals in stacked layers with smooth assemblies were taken place. The photoluminescence spectra illustrated that the annihilation of the plasmonic excitons was sufficiently suppressed in ternary composite. Under solar light irradiation, the designed Mg doped WO3@g-C3N4 ternary nanocomposite shown better photocatalytic activity for Malachite green (MG) degradation than undoped g-C3N4 and WO3@g-C3N4 binary composite. It was also investigated how physical parameters like pH, and catalyst dose affected the photo-degradation of MG as well as examined the recyclability up to 4 cycles. The radical scavenging studies suggested that the primary species responsible for the breakdown of MG by the Mg doped WO3@g-C3N4 ternary nanophotocatalyst materials is the •O2– radicals. Photodegradation of MG followed pseudo-first order kinetics with highest rate constant 0.090 min−1 using ternary composite. The superior visible radiation absorption, enhanced surface area, improved separation efficacy of excited e--h+ couples, and the photo-generated electron movement from g-C3N4 to WO3 bands via Mg can all be contributed to the ternary WO3@g-C3N4 nanocomposite’s excellent photocatalytic performance as well as recyclability.

Dynamics of the role of LacMeta laccase in the complete degradation and detoxification of malachite green.

Laccases highlight for xenobiotic bioremediation, as well as application in the fine chemical, textile, biofuel and food industries. In a previous work, we described the preliminary characterization of laccase LacMeta, a promising enzyme for the bioremediation of dyes, able to decolorization malachite green (MG), trypan blue, methylene blue. Here we demonstrate that LacMeta is indeed suitable for the complete degradation and detoxification of MG dye, not just for its discoloration, since some works show false positives due to the formation of colorless intermediates such as leucomalachite. The optimal pH and temperature parameters of LacMeta were 5.0 and 50°C, respectively (MG as substrate). LacMeta was tolerant of up to 10 mmol L- 1 EDTA (82%) and up to 5% (V/V) acetone (91%) and methanol (71%), while SDS promoted severe inhibition. For ions, a high tolerance to cobalt, zinc, manganese, and calcium (10 mmol L- 1) was also observed (> 90%). Even under high-salinity conditions (1mol L- 1 NaCl), the residual bleaching activity of the dye remained at 61%. Furthermore, the bleaching product of MG did not inhibit the germination of sorghum and tomato seeds and was inert to the vegetative structures of the germinated seedlings. Additionally, this treatment effectively reduced the cytotoxic effect of the dye on microorganisms (Escherichia coli and Azospirillum brasilense), which can be explained by H-NMR spectral analysis results since LacMeta completely degraded the peak signals corresponding to the aromatic rings in the dye, demonstrating extreme efficiency in the bioremediation of the xenobiotic at high concentrations (50mg L- 1).

Band-Structure Engineering of TiO2 Photocatalyst by AuSe Quantum Dots for Efficient Degradation of Malachite Green and Phenol

Band-Structure Engineering of TiO2 Photocatalyst by AuSe Quantum Dots for Efficient Degradation of Malachite Green and Phenol

Polyoxometalate Intercalated MgAl-Layered Double Hydroxide for Degradation of Malachite Green

Polyoxometalate Intercalated MgAl-Layered Double Hydroxide for Degradation of Malachite Green

ZnAl2O4/sulfur-doped g-C3N4 S-scheme heterojunction for efficient photocatalytic degradation of malachite green

In this study, ZnAl2O4 and sulfur-doped g-C3N4 (SCN) S-Scheme heterojunctions were successfully prepared by in situ self-assembly method for the efficient removal of malachite green (MG). The composite structure was formed by loading ZnAl2O4 nanoscale particles onto SCN nanosheets. The results showed that the 30 wt% ZnAl2O4/SCN composite exhibited the best photocatalytic properties. The degradation of malachite green (MG) by 30 wt% ZnAl2O4/SCN composite reached 98.3% after 120 min of simulated solar illumination. Photo-induced •O2− was regarded as the primary active substance in the MG photodegradation. This study is expected to provide new possible strategies for the removal of contaminants MG in water.

Combined Natural Mineral@ZnCoO System for Photocatalytic Degradation of Malachite Green Under Visible Radiation

Combined Natural Mineral@ZnCoO System for Photocatalytic Degradation of Malachite Green Under Visible Radiation

Green Synthesized Silver Nanoparticles Grafted Zinc Ferrite (Ag/Znfe2o4): An Effective Nanocatalyst Fabricated For the Efficient Degradation of Malachite Green (MG) and Methylene Blue (MB)

Green silver nanoparticles (AgNPs) grafted on zinc ferrite (ZnFe2O4) prepared by co-precipitation and calcination are used as a novel nanocatalyst designed for the degradation of malachite green (MG) and methylene blue (MB).

Integrated Adsorption and Photocatalytic Degradation of Malachite Green Using Carbon Based Nanocomposites (ZnO-AC)

Malachite green dye is widely used in dye industries, aquaculture industries and food industries. The prevalence of this malachite green in the effluent of wastewater could potentially harm human health and destroy the aquatic system. Hence, to completely destroy its presence in the effluent, a technique of integrated adsorption and photocatalytic degradation was introduced. Integrated photocatalyst adsorbent (IPCA) utilizing zinc oxide as photocatalyst and supported on activated carbon derived from melinjo shell, ZnO-AC was synthesized. Activated carbon derived from the melinjo shell provides a porous surface for adsorption while zinc oxide is sensitive to photons and enhances better light absorption. ZnO-AC was subjected to scanning electron microscope (SEM) and Fourier Transform infrared spectroscopy (FTIR) characterization. The analysis revealed a porous sponge network and an intense peak of zinc oxide at 650-700 cm−1. The performance of ZnO-AC was evaluated by studying the effect of initial dye concentration (10-50 ppm), pH (2-11) and ZnO-AC dosage (5-25 mg) in the presence of UV light. In this study, the optimum conditions for dye degradation were found to be 10 ppm initial dye concentration, pH 11 and 15 mg ZnO-AC dosage. Kinetic behaviour of the dye degradation was also investigated. The photocatalytic degradation followed Langmuir-Hinshelwood model and the data corresponded well with pseudo-first-order kinetics.

Macroporous flowerlike Bi2O2CO3-CuBi2O4 nanoheterojunction photocatalyst for high concentrated malachite green degradation: Influence of nanocomposite composition and sonication approach

In this work, the novel CuBi2O4 surface-sensitized bismuth subcarbonate as flowerlike sun-light dual-nanoheterojuncted photocatalysts, in different weight ratios of CuBi2O4 to Bi2O2CO3, were prepared via the facile hydrothermal technique with the assistance of ultrasonic waves. Structural characterization, surface morphology, and optical properties of nanophotocatalysts were investigated with XRD, FESEM, TEM, BET-BJH, DRS, and PL analyses. The results represented the highest degradation percentage (91.6 %) for 200 mg/L malachite green over Bi2O2CO3-CuBi2O4 (1:1)-SH nanocomposite under 180 min sunlight irradiation due to two light absorption edges and separation of the charge carriers promoted owing to the heterojunction formation and the specific flowerlike morphology. It has a meso/macroporous structure with 12.4 m2/g surface area, Vmeso= 0.085 cm3/g and Vmacro = 0.039 cm3/g in which facilitates the intra-diffusion and adsorption of malachite green macromolecules Furthermore, the selected nanophotocatalyst stability, reaction mechanism, and kinetic evaluation were examined.

Excellent catalytic performance of mechanically alloyed AlCrFeMnTiZr0.5 high-entropy alloy for malachite green degradation

• AlCrFeMnTiZr 0.5 HEA powder photocatalyst is prepared by mechanical alloying. • AlCrFeMnTiZr 0.5 catalyst exhibits good malachite green degradation under light. • Nano-reactants are mainly oxides or hydroxides of Al and Mn after catalysis. • Nanoparticles and nanosheets covering surface promote adsorption and degradation of MG. • Exfoliated nano-reactants and exposed fresh surface enhance degradation reusability. This work reports that the mechanical alloyed AlFeMnCrTiZr 0.5 high-entropy alloy (HEA) powder was used as catalyst for malachite green (MG) degradation. The HEA with dual solid solutions shows good catalytic performance under visible light. Its efficiency of reaching degradation saturation and maximum degradation rate are much greater than those of Fe 0 powder. The oxides or hydroxides of Al and Mn nucleate and grow on the powder surface, existing in the form of initial nanoparticles and growing nanosheets, which promote the adsorption and catalytic degradation of MG. The exfoliated nano-reactants and exposed fresh powder surface of catalyst enhance the reusability and sustainability of degradation. The catalytic mechanism is mainly visualized by the synergy of chemical dye decomposition and physical dye adsorption.

Green synthesis of iron nanoparticles for malachite green removal

Green synthesis of iron nanoparticles (Fe NPs) using plant extract is a suitable alternative for chemically synthesised Fe NPs due to their low cost, high stability, high reactivity, and environmental compatibility. The objective of the present study is to synthesise Fe NPs from ethanolic seed coat extracts of Strychnos nux vomica (SN) and Abrus precatorius (AP) and to investigate the removal efficiency for malachite green dye (MG). The synthesised AP-Fe NPs exist in crystalline and amorphous forms with particle sizes ranging between 3-32 nm, whereas SN-Fe NPs are amorphous with particle sizes ranging between 2.1-5 nm. The removal efficiency of prepared Fe NPs for MG shows that the AP-Fe NPs were more effective than SN-Fe NPs. The malachite green removal efficiency increases with increasing nanoparticle dosage and contact time. Acidic pH and low initial concentration of the dye solution were the other favourable conditions for malachite green removal. [4-(dimethylamino)phenyl]-phenylmethanone, benzoic acid and diphenylmethanone are the malachite green degradation products identified after treating with AP-Fe nanoparticles. • Fe nanoparticles were prepared using plant extracts of Strychnos nux vomica and Abrus precatorius . • AP-Fe nanoparticles show high malachite green removal efficiency compared to SN-Fe nanoparticles. • Degradation product of malachite green using AP-Fe nanoparticles were identified.

Enhanced photocatalytic organic dye degradation activities of pristine and Zn-doped V2O5 nanoparticles

This research work presents the photocatalytic activities of pristine and Zn-doped V2O5 nanoparticles for the degradation of Methylene Blue (MB), Methyl Violet (MV), and Malachite Green (MG) dyes. The nanoparticles of V2O5 pure and Zn with different atomic ratios (1–5 at%) were prepared by sol–gel method. X-ray diffraction (XRD) studies confirm the orthorhombic phase. X-ray Photoelectron spectroscopy (XPS) confirms the presence of V, O, and Zn elements along with their oxidation states. Further, decreased photoluminescence (PL) intensity spectra confirm the reduced recombination rate. Band structure analysis were studied with valance band XPS (VB-XPS), Mott-Schottky (M−S) curves, and Kubelka-Munk (K-M). The Time resolved photoluminescence (TRPL) and Electrochemical impedance spectroscopy (EIS) studies showed that the charge carrier life time was increased and charge transfer resistance was lowered with increasing Zn concentration. The photocatalytic studies show excellent degradation efficiencies against MB, MV, and MG dyes. The results from the present work show the degradation time decreases as the Zn concentration increases. The reusability test was performed and the dye degradation (DD) mechanism with their kinetics are discussed in detail with the radical test. The consistency of the samples were tested by taking XRD, FTIR and BET analysis after three trials of usage.

Enzymes analysis, degradation kinetics, response surface optimization and heavy metal tolerance of the biodegradation of malachite green by Stenotrophomonas koreensis

Stenotrophomonas koreensis, was isolated from a textile effluent and employed to biologically degrade 98.8% of the recalcitrant toxic dye malachite green in 4 h in the absence of any supplements or media. Chromatographic and Spectroscopic analysis confirmed the degradation of the dye. According to Response Surface Methodology, the optimum conditions for biodegradation were pH 6, inoculum size 6 mL (initial concentration Log10CFU/mL = 6.2), and temperature 45 °C. More than 98% decolorization was achieved within 2.5 h of the addition of soymeal extract or peptone. One of the most promising features of this strain is that even in the presence of heavy metals, S. koreensis actively degraded the dye. The bacteria biodegraded malachite green following the first-order reaction kinetics. LC-MS analysis of the degradation product yielded several intermediates like Michler’s ketone (m/z 269), 4-N,N-dimethylaminophenol (m/z 137), Benzophenone (m/z 182), N,N-dimethylaniline (m/z 121), 4-(N-methylamino)-benzophenone (m/z 211), 4-aminobenzaldehyde (m/z 121), anionic canonical form of 4-aminobenzaldehyde (m/z 120), 4-(N,N-dimethylamino)benzoic acid (m/z 165), 4-(N-methylamino) benzoic acid (m/z 152). The enzymes responsible for the malachite green degradation were tyrosinase, Malachite Green reductase, and NADH-DCIP reductase. The present work is the first to report the degradation of malachite green by S. koreensis.

Pd loaded bismuth ferrite: A versatile perovskite for dual applications as acetone gas sensor and photocatalytic dye degradation of malachite green

Herein we report the palladium loaded bismuth ferrite for its bidirectional application as acetone gas sensor and photocatalytic dye degradation of malachite green. The motivation for loading Pd on bismuth ferrite (BFO) is due to its fascinating catalytic redox reactions causing faster adsorption and desorption of the oxygen molecules over the metal oxide. The planned perovskites were developed via surfactant assisted sol-gel auto-combustion route, and characterized their physico-chemical properties using XRD, SEM, TEM, HRTEM, EDAX, XPS and BET. The developed BFO showed the best selectivity towards acetone, whose response was 69% at 300 °C operating temperature for 500 ppm gas concentration. By tuning the surface area and catalytic behavior using CTAB and Pd loading, respectively, the enhancement in the gas response properties of BFO was achieved to 95% with the response and recovery time of 75 s and 104 s. The 1 wt% Pd loaded BFO showed the highest response (95%) in comparison to rest of the Pd loadings (0.5, 1.5 and 2.0 wt%). Moreover, the sunlight driven photocatalytic dye degradation of malachite green is carried out at 1 h exposure time. Here as well, 1 wt% Pd loaded BFO exhibited the maximum dye degradation efficiency of 51%. The results of this study demonstrate the developed perovskites have a significant potential for the use in dual applications such as acetone gas sensor and MG photocatalysis.