Malachite Green Research Articles

Innovative fabrication of highly efficient CeO2 ceramic nanomaterials for enhanced photocatalytic degradation of toxic contaminants under sunlight

In this research, we report an innovative sonochemical technique for synthesizing cerium oxide (CeO2) nanoparticles utilizing glucose as a capping agent, significantly boosting their photocatalytic performance under visible light. Through meticulous optimization, our CeO2 nanoparticles demonstrated exceptional degradation efficiencies: 97.2 % for Acid Red 14, 99.1 % for Captopril, 98.7 % for Malachite Green, and 98.3 % for Amlodipine, substantially outstripping performance metrics of commercial TiO2 and untreated samples. Our kinetic analyses, based on the Langmuir-Hinshelwood model, indicated a superior rate constant of 0.0701 min⁻1 for Acid Red 14 degradation—reflecting a stark enhancement over other catalysts tested. Furthermore, mechanistic insights revealed that the significant improvement in photocatalytic activity was predominantly due to the generation of hydroxyl radicals and effective utilization of electron vacancies, with the role of these reactive species validated by detailed scavenger tests. This enhancement in photocatalytic efficiency is attributed to the sonochemical synthesis paired with glucose modification, which optimizes the nanoparticles' surface characteristics crucial for reactivity. Moreover, the nanoparticles showcased remarkable stability and reusability, maintaining an 87.8 % degradation rate after 11 cycles, evidencing minimal loss in activity and underscoring their potential for long-term applications in environmental remediation. This study not only paves the way for the practical application of CeO2 nanoparticles in pollutant degradation but also illustrates the broader applicability of sonochemically synthesized nanomaterials in sustainable environmental management, offering a promising solution to the challenge of complex organic pollutants in aquatic environments.

Toxicological Impact of Malachite Green on Freshwater Fish: A Comprehensive Review

Triarylmethane dyes, such as malachite green, are widely used in the culinary, pharmaceutical, textile, and other sectors for a variety of purposes, including aquaculture parasiticides. It controls fungal attacks, protozoan infections, and some other diseases caused by helminthes on a wide range of fish and aquatic organisms. Nonetheless, the dye's purportedly harmful effects have raised a lot more questions about its usage. The exposure time, temperature and the concentration all raise the dye's toxicity. It has been linked to chromosomal breaks, mutagenesis, cancer,teratogeneity, and pulmonary toxicity. Multi-organ tissue damage is one of malachite green's histopathological consequences. Fish exposed to malachite green have notable changes in their blood's biochemical characteristics. Malachite green and its reduced form, leucomalachite green, have been found in a variety of tissues, including eggs and fries, as well as serum, liver, kidney, and muscles. Despite a wealth of information about malachite green's toxicity, several developing countries still utilize it as a parasiticide in aquaculture and other industries. Hence, there is a significant likelihood of malachite green disposition in the food chain. To counteract its toxicological effect, it is crucial to identify a substitute because of its high toxicity.

ZnO nanostructures grown from spent batteries: Ambient catalytic aspects and novel mechanistic insights

The present work includes a facile and economic microwave assisted hydrothermal synthesis of Zinc Oxide (ZnO), Diethylene Triamine Pentaacetic Acid (DTPA) stabilized Zinc Oxide (ZD) and DTPA stabilized Silver doped Zinc Oxide (ZAD) nanostructures using Zn from spent alkaline batteries. The synthesised nanostructures were well characterised using electronic, vibrational and X-Ray spectroscopic techniques as well as thermal and microscopic techniques revealing the successful stabilisation of DTPA in ZD and doping of Ag in ZAD. The Fourier Transform Infrared Spectroscopy (FTIR) spectra showed peaks characteristic to the presence of ZnO in the fingerprint region and those to the presence of DTPA. The X-Ray Diffraction Spectroscopy (XRD) pattern of ZnO, ZD and ZAD indicated the hexagonal wurtzite structure of ZnO and face centred cubic metallic Ag in ZAD. The Transmission Electron Microscopy (TEM) images revealed rod shaped morphology for ZnO and spherical morphologies for ZD and ZAD. The nanostructures proved to be efficient catalysts to achieve 100 % degradation of Malachite Green, Crystal Violet and Reactive Blue-21 and their binary mixtures under ambient conditions in presence of Hydrogen peroxide (H2O2). ZAD exhibited relatively rapid degradation with rate constants 0.754 min−1, 0.187 min−1 and 0.0150 min−1 for MG, CV, and RB-21 respectively as well as 99 % reduction in Chemical Oxygen Demand (COD) value of the dye solutions. Scavenging studies and Electron Paramagnetic Resonance (EPR) studies using different spin trapping agents revealed the involvement of singlet oxygen species, hydroxyl radicals (OH.) and superoxide radicals (O2.-) in the degradation process. This work aligns with Sustainable Development Goals 6, 12 and 13.

Elevating electron transfer of recyclable SERS sensor using AuNPs/TiO2/Ti3C2 heterostructures for detection of malachite green in sunfish

Malachite green (MG)-contaminated aquatic products pose a serious threat to animal and human health. Hence, a novel recyclable surface-enhanced Raman scattering (SERS) substrate based on AuNPs/TiO2/Ti3C2 heterostructures was developed for the detection and degradation of MG in aquatic products. Specifically, AuNPs/TiO2/Ti3C2 heterostructures were synthesized by in situ oxidation and electrostatic adsorption based on Ti3C2 nanosheets. The excellent photocatalytic and SERS performance of the AuNPs/TiO2/Ti3C2 was demonstrated by Density functional theory (DFT) calculations and experimental results, which was attributed to the enhancement of charge transfer (CT) after the formation of heterostructures. The results demonstrate that AuNPs/TiO2/Ti3C2 is highly sensitive and recyclable. The detection limit of the sensor for MG is 8.91 × 10−5 mg/L. The sensor can be recycled for five times under the condition of light, and shows satisfactory self-cleaning performance in the food matrix, providing a possible alternative solution for the recyclable detection of MG.

Synthesis of multifunctional rGO/g-C3N4/FeTiO3 ternary nanocomposites for photocatalyst, antibacterial, and ecotoxicity assessment of zebrafish embryo model

The wastewater from the dye and pharmaceutical industries antibiotics has caused serious environmental and health problems for humans and other species. For the development of superior photocatalysts, effective separation of photogenerated electron-hole pairs is essential in addition to optimizing solar absorption throughout a wide wavelength range. In order to produce bare, rGO/g-C3N4, rGO/FeTiO3, and rGO/g-C3N4/FeTiO3 (GCNFeT NCs) nanocomposites, this study describes the fabrication of perovskite-type titanate (FeTiO3) and its incorporation onto graphitic carbon nitride (g-C3N4) and reduced graphene oxide (rGO) using a hydrothermal synthesis technique. The generated nanocomposites structural, morphological, and optical properties were evaluated. After being exposed to solar light for 90 min, the resultant GCNFeT NCs efficiently broke down 80 % of Tetracycline (TC) and 90 % of Malachite Green (MG) dye. The photocatalytic efficacy is significantly improved by these results when compared to the pure and binary composites. Substantial catalytic efficiency to GCNFeT NCs was shown by the degradation rate constant (k) for MG and TC elimination by GCNFeT NCs, which was almost 20 times greater than that of pure and binary composites. Additionally, the antibacterial activity of GCNFeT nanocomposites was studied, and the results showed that it was significantly more efficient against Gram-negative bacteria than Gram-positive bacteria, including Escherichia coli and Staphylococcus aureus. Furthermore, the freshwater zebrafish embryo development proved effective in assessing the non-toxicity of GCNFeT NCs. Our research findings indicate that high doses, GCNFeT NCs induce less toxicity in zebrafish embryo (6.25–100 µg/L). These results demonstrated the enhanced mechanism of GCNFeT NCs, indicating their great potential for use in antibacterial and water remediation applications.

Engineered hybrid iron‐cobalt metal oxide nanoparticles for effective adsorption of malachite green dye

AbstractBACKGROUNDHybrid iron and cobalt metal oxide nanoparticles are well known; however, are not optimized in terms of size and stability. We engineered these hybrid nanoparticles using the co‐precipitation method and characterized them by various techniques, which are then used for the effective adsorption and removal of malachite green (MG) dye.RESULTSThe ideal conditions for synthesis are determined to be 50:50 ratio of Fe2O3 and CoO, pH of 11, temperature range of 40 °C–60 °C, and reactant addition time of 20 min. These hybrid nanoadsorbents effectively eliminated MG dye from aqueous solutions. Factors such as initial MG dye concentration, pH of the medium, contact time, temperature, and nanoadsorbent dose were optimized for the MG removal to achieve a maximum removal efficiency of 96.9%. Non‐linear fitting of data indicates that both Langmuir and Freundlich models provided the best fit, suggesting the presence of both monolayer and multilayer adsorption of MG on hybrid nanoparticles. The kinetics of MG dye removal are better controlled by the intraparticle diffusion (IPD) phenomenon. The adsorption of MG onto the hybrid nanoparticles was confirmed to be endothermic, with negative ΔG and positive ΔH values. The optimized synthetic conditions also positively impacted the hybrid nanoparticles which enhanced the adsorption and exhibited ferromagnetic behavior as compared to the superparamagnetic behavior reported in the literature, making them significantly important for dye removal applications.CONCLUSIONThese findings demonstrate the potential of optimized hybrid nanoparticles as effective nanoadsorbents for dye removal applications, with implications for further applications in photocatalysis and sensing. © 2024 Society of Chemical Industry (SCI).

Corn Husk‐Derived Carbon Fused with Iron Oxide as Adsorbent for Cationic Dyes

AbstractThe development of nanomaterials for dye degradation has garnered significant interest due to their efficiency, environmental benefits, and cost‐effectiveness. In this study, a nanocomposite adsorbent composed of α‐Fe2O3 coupled with carbon derived from eco‐friendly corn husk has been developed. This material effectively captured cationic dyes, Methylene Blue (MB) and Malachite Green (MG), from aqueous solutions, including industrial dye effluent from local industry. The synthesized nanocomposite demonstrated rapid removal of MB and MG from the solution without the need for additional oxidizing or reducing agents. The adsorption conditions by varying parameters such as adsorbent dose, contact time, solution pH, initial dye concentration, and temperature have been optimized. Adsorption isothermal studies indicated that the Langmuir isotherm model best explained the adsorption process. Kinetic studies revealed that the adsorption process follows a pseudo‐first‐order model for MB, while the intraparticle diffusion model is more appropriate for MG. Moreover, the nanocomposite exhibited excellent reusability and regenerability for dye adsorption. Our study showcases the effectiveness of the synthesized nanocomposite adsorbent, comprising α‐Fe2O3 integrated with carbon derived from eco‐friendly corn husk using a simple and sustainable methodology, in efficiently removing cationic dyes from textile wastewater. This approach offers a promising solution for environmental remediation.

Efficient removal of high concentration dyes from water by functionalized in-situ N-doped porous biochar derived from waste antibiotic fermentation residue

Using biochar for dye wastewater treatment is attracting interest due to its excellent adsorption properties and low costs. In this work, a novel biochar derived from oxytetracycline fermentation residue (functionalized OFR biochar, FOBC) was investigated as a efficient adsorbent for typical dyes removal. At 25 °C, the maximum adsorption capacity calculated by Langmuir model of FOBC-3-600 for methylene blue (MB), malachite green (MG), and methyl orange (MO) reached 643.97, 617.89, and 521.03 mg/g, respectively. The kinetics and isotherm model fitting showed that the chemisorption and physisorption both occurred during the adsorption process. Dyes were efficiently adsorbed through pore filling, electrostatic attraction, π-π interactions, and surface complexation. And the cycling experiment and environmental risk assessment indicated that the FOBC-3-600 had excellent recyclability and utilization safety. Overall, this study provides a practical method to simultaneously treat the dyeing wastewater and utilize the antibiotic fermentation residue.

Highly efficient malachite green adsorption by bacterial cellulose and bacterial cellulose/locust bean gum composite

In this study, bacterial cellulose (BC) and BC/locust bean gum (LBG) composite produced from banana hydrolysate were both used as the adsorbent for various organic dyes adsorption especially for malachite green (MG) adsorption for the first time. The BC/LBG(2%) composite exhibited significantly enhanced swelling rate and textural characteristics while maintained the basic structure of BC as depicted by XRD, FT-IR, and NMR, providing a foundation for its application as an excellent adsorbent. The composite exhibited a high adsorption rate and adsorption capacity for MG (exceeding 95 % and 2000 mg/g), and had a good selectivity for MG adsorption in the solution containing crystal violet (CV), rhodamine B (RB), and methyl orange (MO). The MG adsorption process conformed to multiple models including Langmuir and pseudo-first-order models. And the adsorption mechanism mainly comprised chemical adsorption (hydrogen bonding and electrostatic interactions) and physical adsorption. The reusability of BC/LBG(2%) composite was attractive for industrial application that the MG adsorption rate reduced merely a little (still higher than 88 %) after the 5th regeneration process. Overall, considering its adsorption capacity, selectivity, and reusability, BC/LBG(2%) composite prepared by in-situ fermentation with LBG addition was a competent adsorbent for MG adsorption and MG containing wastewater treatment.

Fully integrated sensor array for additives, permittivity, and pH monitoring for fishery

Additive abuse in fishery, such as tricaine methanesulfonate (MS222), ciprofloxacin (CPFX), and malachite green (MG), threatens public human health and interferes with the ecological equilibrium of water resources. However, the majority of the present detection methods suffer from high costs, complex operations, and poor portability. Therefore, real-time and rapid detection of the above additive by mobile devices is becoming increasingly important. Here we report the fabrication and performance of an entirely electrochemical system with USB-stick size for simultaneous detection of MS222, CPFX, and MG, as well as pH and permittivity. The limits of detections are 0.17, 0.67, and 0.28 µg/mL, while the resolution ratios are 10 %, 10 %, and 5 % for MS222, MG, and CPFX, respectively. For both pH and permittivity, they have linear regressions measured by brightness and capacitance of the sample respectively, at the range of 1.5–9 (pH) and 10–20 (permittivity). The interference experiments, using target analytes (40 μg/mL) and 15 interfering analytes (80 μg/mL), demonstrated the anti-interference performance of the sensor patches. The field studies on carps, catfishes, and chubs indicated that the developed integrated portable system could be used for real sample analysis with high performance.

Sustainable Wastewater Treatment with Bi2MoO6/Cellulose Acetate Photocatalytic Membranes

AbstractA major challenge for modern society is securing quality water for various uses. Membrane water treatment will be crucial for drinking water, desalination, and wastewater reuse. The development of bismuth molybdate (Bi2MoO6) nanoparticles has enabled the production of novel Bi2MoO6‐incorporated cellulose acetate (CA) membrane nanocomposite. The synthesized Bi2MoO6/CA nanocomposites are thoroughly examined for their structural, morphological, and photocatalytic characteristics using X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) with energy dispersive X‐ray spectroscopy (EDX) analysis. The photocatalytic properties are determined by evaluating the degradation of Malachite Green (MG) and Rose Bengal (RB) by the nanocomposite membranes under the illumination of a UV light simulator. Notably, the Bi2MoO6/CA nanocomposite membrane displays exceptional and sustained photocatalytic efficiency (78%) and (84%) in MG and RB dye degradation, respectively. Moreover, the effective loading of the Bi2MoO6 onto the CA membrane enhances electron and hole adsorption while facilitating carrier movement. Furthermore, the stability exhibited by the Bi2MoO6/CA nanocomposite photocatalysts remains impressive even after multiple cycles, demonstrating their durability. This research introduces a cutting‐edge semiconductor‐based hybrid nanocomposite material that proves highly efficient in the photocatalytic degradation of organic dyes, showcasing promising advancements in environmental remediation strategies.

COMPARISON OF MALACHITE GREEN AND METHYLENE BLUE DYES IN NON-SURGICAL PERIODONTAL TREATMENT IN PATIENTS LIVING WITH HIV/AIDS AND UNDERGOING IMMUNE RECONSTITUTION

The aim of this study was to evaluate the effect of photodynamic therapy (PDT) on non-surgical periodontal treatment in patients failing highly active antiretroviral therapy (HAART). comparing methylene blue (MB) (0.01%) and malachite green (MG) (0.01%) dyes as a therapeutic protocol, measuring the following periodontal clinical parameters: clinical probing depth (CPD), gingival recession (GR), clinical attachment level (CAL), full-mouth plaque index (PI), and full-mouth bleeding index (BI), using polymerase chain reaction (PCR) for identification of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), and Tannerella forsythia (Tf) pathogens. The study was approved by the Research Ethics Committee. Forty-four patients were evaluated, 15 (34.1%) female and 29 (65.9%) male. The mean age was 46 years. In the evaluation of GR, there was a significant difference in the non-resistant group in which MB was used. Resistant patients treated with MG or MB showed significant differences in the decrease of Pg bacteria. PDT associated with MB promoted improvements in CPD and decrease of Aa and Pg bacteria, being an effective therapeutic protocol.

Recent Advances in Utilizing Lignocellulosic Biomass Materials as Adsorbents for Textile Dye Removal: A Comprehensive Review.

This review embarks on a comprehensive journey, exploring the application of lignocellulosic biomass materials as highly effective adsorbents for the removal of textile dyes (cationic and anionic dyes) from wastewater. A literature review and analysis were conducted to identify existing gaps in previous research on the use of lignocellulosic biomass for dye removal. This study investigates the factors and challenges associated with dye removal methods and signifies their uses. The study delves into the pivotal role of several parameters influencing adsorption, such as contact time, pH, concentration, and temperature. It then critically examines the adsorption isotherms, unveiling the equilibrium relationship between adsorbent and dye and shedding light on the mechanisms of their interaction. The adsorption process kinetics are thoroughly investigated, and a detailed examination of the adsorbed rate of dye molecules onto lignocellulosic biomass materials is carried out. This includes a lively discussion of the pseudo-first, pseudo-second, and intra-particle diffusion models. The thermodynamic aspects of the adsorption process are also addressed, elucidating the feasibility and spontaneity of the removal process under various temperature conditions. The paper then dives into desorption studies, providing insights into the regeneration potential of lignocellulosic biomass materials for sustainable reusability. The environmental impact and cost-effectiveness of employing lignocellulosic biomass materials in textiles including Congo Red, Reactive Black 5, Direct Yellow 12, Crystal Violet, Malachite Green, Acid Yellow 99, and others dyes from wastewater treatment are discussed, emphasizing the significance of eco-friendly solutions. In summary, this review brings together a wealth of diverse studies and findings to present a comprehensive overview of lignocellulosic biomass materials as adsorbents for textile cationic and anionic dye removal, encompassing various aspects from influential parameters to kinetics, adsorption isotherms, desorption, and thermodynamics studies. Its scope and other considerations are also discussed along with its benefits. The collective knowledge synthesized in this paper is intended to contribute to the advancement of sustainable and efficient water treatment technologies in the textile industry.

Simultaneous removal of malachite green and lead from water by consortium dry-biomasses of Bacillus licheniformis AG3 and Bacillus cereus M116

Synthetic textile dye malachite green (MG) and heavy metals present in industrial wastewater are hazardous to the ecosystem. Bioremediation of dyes and heavy metals using dry-biomasses has advantages over chemical methods. This study screened an acclimatized, heavy metal-resistant, and dye-degrading Gram positive Bacillus licheniformis AG3 strain from the textile wastewater near Kolkata, West Bengal. The EDXRF analysis of this colored wastewater effluent showed 36.33 mg/L lead, significantly higher than the WHO recommendation. Previously, Bag et al. showed bioremediation of synthetic dyes using dry-biomass of Bacillus cereus M116 from an aqueous solution (Bag et al. Arch Microbiol 203(7):3811–3823, 2021). Here, a consortium of dry-biomasses of B.licheniformis AG3 and B. cereus M116 strains (1:1 w/w ratio) was prepared for the simultaneous removal of lead and MG from wastewater. Statistical optimization determines that the pH, initial concentration of contaminants, and dry-biomass concentrations are critical for bioremediation under batch procedures. Further, optimization using the response surface methodology showed that 0.01% consortium dry-biomasses eliminated a maximum of 99.35% MG and 96.01% lead (II) within 6 h. SEM–EDS and FTIR confirmed a strong surface biosorption. Furthermore, a fixed-bed biofilter column of the consortium dry-biomasses was prepared, which was able to remove 98.1% MG and 98.5% lead at the 0.5–1 mL/min flow rate. Together, this study developed a biofilter with a consortium dry biomasses of B. licheniformis AG3 and B. cereus M116 for the simultaneous removal of MG and lead from wastewater.

Enhanced Photocatalytic Performance under Ultraviolet and Visible Light Illumination of ZnO Thin Films Prepared by Modified Sol-Gel Method.

Semiconductor oxides are frequently used as active photocatalysts for the degradation of organic agents in water polluted by domestic industry. In this study, sol-gel ZnO thin films with a grain size in the range of 7.5-15.7 nm were prepared by applying a novel two-step drying procedure involving hot air treatment at 90-95 °C followed by conventional furnace drying at 140 °C. For comparison, layers were made by standard furnace drying. The effect of hot air treatment on the film surface morphology, transparency, and photocatalytic behavior during the degradation of Malachite Green azo dye in water under ultraviolet or visible light illumination is explored. The films treated with hot air demonstrate significantly better photocatalytic activity under ultraviolet irradiation than the furnace-dried films, which is comparable with the activity of unmodified ZnO nanocrystal powders. The achieved percentage of degradation is 78-82% under ultraviolet illumination and 85-90% under visible light illumination. Multiple usages of the hot air-treated films (up to six photocatalytic cycles) are demonstrated, indicating improved photo-corrosion resistance. The observed high photocatalytic activity and good photo-corrosion stability are related to the hot air treatment, which causes a reduction of oxygen vacancies and other defects and the formation of interstitial oxygen and/or zinc vacancies in the films.

Plant-mediated bimetallic nanoparticles synthesis for catalytic degradation of malachite green

Plant-mediated bimetallic nanoparticles synthesis for catalytic degradation of malachite green

Enhanced degradation of dyes using a novel CuS/g-C3N4/rGO ternary composite catalyst: Synthesis, characterization, and mechanistic insights

This work reports the synthesis, characterization, and application of a novel CuS/g-C3N4/rGO ternary composite catalyst for the enhanced degradation of dyes. CuS nano-flowers, and the composites CuS/rGO, CuS/g-C3N4, and CuS/g-C3N4/rGO were synthesised using the hydrothermal method and characterized by XRD, SEM, FTIR, UV–Vis, and PL spectroscopy. These samples were studied for the photocatalysis of Malachite green (MG) and Murexide (MX) dyes under visible light. Among the four samples, the CuS/g-C3N4/rGO ternary composite has shown 97.05 % and 72.16 % degradation for MG and MX dyes respectively at the timeframe of 70 min. The results are obtained for a little catalytic load of 10 mg and a higher dye concentration of 25 ppm. Detailed mechanistic insights into the dye degradation process were obtained through the analysis of band-edge potential supported by Impedance and PL spectra. The enhancement in the photocatalytic property of the ternary composite can be attributed to the synergistic effects between individual components, including enhanced light absorption, efficient charge separation and improved catalytic activity. The obtained results demonstrate that the novel ternary composite, CuS/g-C3N4/rGO is a promising catalyst for the degradation of MG and MX dyes in wastewater treatment applications.

Fabrication of high-crystallinity hydrazone‐linked fluorescent covalent organic framework and its sulfonated material for the design of sensing and adsorption dual-functional platforms

Hydrazone-linked fluorescent covalent organic frameworks (COFs) with high crystallinity exhibit remarkable stability under acid-base conditions and in various organic solvents, maintaining structural integrity for cyclic utilization in sensing and adsorption processes. Consequently, developing new high-crystallinity hydrazone-linked fluorescent COFs is of significant importance. Notably, post-modification can enhance the detection diversity, selectivity, and adsorption performance of these COFs. Herein, a new hydrazone-linked fluorescent COF (namely COF-YYL) with high crystallinity was synthesized using 2,5-bis(allyloxy)terephthalohydrazide (DHzDAll) and 4,4′,4″-(1,3,5-triazine-2,4,6-triyl)tribenzaldehyde (TTB) as precursors at room temperature. COF-YYL demonstrated superior characteristics including a high specific surface area (653.33 m2·g−1), good chemical and thermal stability, and dual-functionality in detecting methyl orange (MO) and Cu2+ with limits of detection (LODs) of 33 nM (2.1 ng·mL−1) and 1 ng·mL−1, respectively, and an MO adsorption capacity of 112.81 mg·g−1. To increase functional diversity, COF-YYL underwent post-modification via “click” chemistry between the double bonds on DHzDAll and −SH on 3-mercapto-1-propanesulfonic acid sodium salt (MPS), yielding COF-SO3Na. Compared with COF-YYL, COF-SO3Na exhibited a higher specific surface area (815.23 m2·g−1), better dispersion performance, and richer functional group properties. Leveraging these advantages, COF-SO3Na served as a dual-function platform for detecting and adsorbing four cationic dyes including brilliant green (BG), crystal violet (CV), malachite green (MG), and methylene blue (MB), with satisfactory LODs (170 ng·mL−1) and good adsorption capacities ranging from 98.94 to 162.87 mg·g−1. Further, COF-YYL and COF-SO3Na were used to analyze related analytes in tap water samples, achieving satisfactory recoveries. This study introduces a new high-crystallinity hydrazone-linked fluorescent COF, along with its sulfonated material, increasing the diversity of detection and adsorption platforms.

Up-conversion luminescence and Bi SPR effect promoted Z-scheme BiVO4(040)-Bi-(NaYF4:Er,Yb,Tm@BiOBr)/Bi photocatalyst for efficient photocatalytic hydrogen production with simultaneous degradation of malachite green

Photocatalytic hydrogen production with simultaneous degradation of organic pollutants by using solar energy provide a promising strategy to solve the energy and environmental issue in the future. However, for onefold wide band-gap semiconductor, the poor photocatalytic efficiency limits its application on a large scale due to its easy recombination of photo-generated electron-hole pairs and low solar energy utilization. Herein, a novel Z-scheme BiVO4(040)-Bi-(NaYF4:Er,Yb,Tm@BiOBr)/Bi photocatalyst is prepared via photo-assisted isoelectric point method. In this composite photocatalyst, up-convention luminescence material, NaYF4:Er,Yb,Tm, can offer more ultraviolet light and visible light to intensify the activations of BiOBr and metal Bi nanoparticles, respectively. Furthermore, the formation of Z-scheme BiVO4(040)-BiOBr photocatalystic sytem, the spatial separation of the BiVO4(040) and BiVO4(110) facets and the presence of metal Bi surface plasmon resonance effect are contributed to the high-efficiency separation of the photo-generated electron-hole pairs. The experimental results show that as-prepared Z-scheme BiVO4(040)-Bi-(NaYF4:Er,Yb,Tm@BiOBr)/Bi photocatalyst exhibits advanced photocatalytic hydrogen production amount (192.0 μm) and excellent degradation ratio of malachite green (88.51 %) under simulated sunlight irradiation for 5.0 h. The apparent quantum yield of the Z-scheme BiVO4(040)-Bi-(NaYF4:Er,Yb,Tm@BiOBr)/Bi photocatalyst at 420 nm reaches a specific value of 5.8 %. In addition, Z-scheme BiVO4(040)-Bi-(NaYF4:Er,Yb,Tm@BiOBr)/Bi photocatalyst also remains a high stability in the photocatalytic hydrogen production with simultaneous degradation of malachite green within six reuse. At last, the possible reaction mechanism and degradation pathways of malachite green caused by Z-scheme BiVO4(040)-Bi-(NaYF4:Er,Yb,Tm@BiOBr)/Bi photocatalyst under simulated sunlight irradiation are put forward.

Removal of congo red and malachite green from aqueous solution using ternary GO/Bi2O3/MgO materials by co-precipitation method

The present work describes the preparation of Bismuth oxide and magnesium oxide modified with graphene oxide (GO/Bi2O3/MgO) using the co-precipitation method for the elimination of malachite green (MG) and congo red (CR) dyes from aqueous solution. The synthesized GO/Bi2O3/MgO materials were analyzed by using FTIR, SEM, XRD, EDX and EDS. The batch experiment was aimed to investigate the adsorption process by varying various parameters of optimum value for CR and MG dye adsorption such as adsorbent dosage was 100 mg, contact time was 30 min, stirring speed was 250 rpm, initial dye concentration was 30 mg L−1 and pH was 6.5. From experimental data, we concluded that for elimination of MG and CR dye with higher coefficient value (R2) was best fitted with the Langmuir isotherm model. The maximum adsorption capacity was observed to be 45.454 mg/g for MG and 58.823 mg/g for CR, respectively. The mechanism of the adsorbent and both the dyes were explained by electrostatic interaction, π-π interaction, and hydrogen bonding. To check the stability of the GO/Bi2O3/MgO materials, we performed the reusability study using various solvents like methanol, ethanol, water, sodium hydroxide and acetone. Among various solvents, NaOH has shown maximum desorption of both dyes.