Green Synthesis Of Iron Nanoparticles Research Articles

Essential oil analysis of Rhaponticum repens (L.) Hidalgo, and its application in green synthesis of iron nanoparticles to remove Cr (VI) ions from aqueous solutions

Acroptilon repens is a widespread weed in Asia, and has a complicated taxonomy. Recent taxonomical treatment explored that Acroptilon species must be classified in the genus Rhaponticum. Therefore, the scientific name of this species has been converted into Rhaponticum repens. In the current study, essential oil composition, and its ability to green synthesis of iron nanoparticles for future use to adsorb Cr (VI) ions pollution of aquatic solution were evaluated for the first time. The GC-MS analysis revealed oxygenated monoterpenes constituted great proportion of the essential oil, with 1,8-cineole and camphor as the main essential oil components. Several appropriate methods, including UV-Vis, FTIR, XRD, SEM, DLS, and VSM revealed the green synthesis of a mixture of Fe3O4 and Fe2O3 nanoparticles by the extracted essential oil. Sizes of the produced nanoparticles were not equal and detected in the range of 3 to 50 nm, with an average size of 31.5 nm and the magnetic property of 15 emu/g. The green-synthesized nanoparticles could adsorb Cr (VI) ions pollution from aquatic solutions. However, under an optimum condition, the Cr (VI) ions adsorption capacity and removal were 167.6 mg/g and 91%, respectively. Findings revealed the major essential oil composition highly differed from those reported in the previous phytochemical studies. Although the synthesized nanoparticles were not uniform, they could remove Cr (VI) ions pollution.

Supercapacitors and triboelectric nanogenerators based on electrodes of greener iron nanoparticles/carbon nanotubes composites

The development of supporting materials based on carbon nanotubes (CNTs) impregnated with iron nanoparticles via a sustainable and green synthesis employing plant extract of Punica granatum L. leaves was carried out for the iron nanoparticle modification and the following impregnation into the carbon nanotubes composites (CNT-Fe) that were also coated with polypyrrole (CNT-Fe + PPy) for use as electrode for supercapacitor and triboelectric nanogenerators. The electrochemical characterization of the materials by cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) assays revealed that the CNT-Fe + PPy gave rise to better performance due to the association of double-layer capacitance behavior of carbon derivative in association with the pseudocapacitance contribution of PPy resulting in an areal capacitance value 202 mF/ cm2 for the overall composite. In terms of the application of electrodes in triboelectric nanogenerators, the best performance for the composite of CNT-Fe + PPy was 60 V for output voltage and power density of 6 μW/cm2. The integrated system showed that the supercapacitors can be charged directly by the nanogenerator from 0 to 42 mV in 300 s. The successful green synthesis of iron nanoparticles on CNT and further PPy coating provides a feasible method for the design and synthesis of high-performance SCs and TENGs electrode materials. This work provides a systematic approach that moves the research front forward by generating data that underpins further research in self-powered electronic devices.

Synthesis and characterization of iron oxide nanoparticles from Lawsonia inermis and its effect on the biodegradation of crude oil hydrocarbon.

Crude oil hydrocarbons are considered major environmental pollutants and pose a significant threat to the environment and humans due to having severe carcinogenic and mutagenic effects. Bioremediation is one of the practical and promising technology that can be applied to treat the hydrocarbon-polluted environment. In this present study, rhamnolipid biosurfactant (BS) produced by Pseudomonas aeruginosa PP4 and green synthesized iron nanoparticles (G-FeNPs) from Lawsonia inermis was used to evaluate the biodegradation efficiency (BE) of crude oil. The surface analysis of G-FeNPs was carried out by using FESEM and HRTEM to confirm the size and shape. Further, the average size of the G-FeNPs was observed around 10nm by HRTEM analysis. The XRD and Raman spectra strongly confirm the presence of iron nanoparticles with their respective peaks. The BE (%) of mixed degradation system-V (PP4+BS+G-FeNPs) was obtained about 82%. FTIR spectrum confirms the presence of major functional constituents (C=O, -CH3, C-O, and OH) in the residual oil content. Overall, this study illustrates that integrated nano-based bioremediation could be an efficient approach for hydrocarbon-polluted environments. This study is the first attempt to evaluate the G-FeNPs with rhamnolipid biosurfactant on the biodegradation of crude oil.

Green synthesis of iron nanoparticles using Pistacia-atlantica leaf extract for enhanced removal of Cr(VI) from aqueous solution

The discharge of chromium-containing wastewater from various industries into aqueous environments is regarded as an important and challengeable matter due to its high toxicity. The application of conventional methods for eliminating this pollutant are often very expensive and difficult. Therefore, the adsorption process has been introduced as a desirable and effective method for removing chromium ions from aqueous media. In this research, iron nanoparticles (Fe-NPs) were synthesized using Pistacia-atlantica leaf extract as a reducing agent, then they were characterized by DLS, XRD, FT-IR, FESEM/EDS, and TEM techniques and its effectiveness to eliminate hexavalent chromium (Cr (VI)) from aqueous solutions was carried out. The capability of the batch adsorption procedure was assessed under different operational factors, such as initial pH, adsorbent dose and initial Cr (VI) concentration. Optimum adsorption conditions were determined at initial pH of 2, Cr (VI) concentration of 25 mg L−1 and adsorbent dose of 0.24 g L−1. Based on the obtained results, the highest removal efficiency (99.9%) by the adsorption process was occurred at pH of 2, concentration of 5 mg L−1 and 30 min of operational time. On the other hand, the results showed that the percentage of the pollutant elevated by increasing the contact time and amount of adsorbent dose, whereas that of was declined by increasing the initial concentration of Cr (VI). Besides, the experimental equilibrium data was evaluated by Langmuir, Freundlich, and Temkin isotherm models, and the outcomes revealed conformity with the Langmuir isotherm model. The Cr (VI) adsorption utilizing Fe-NPs adhered to a pseudo-first-order kinetic model. Eventually, thermodynamic studies demonstrated that the adsorption of Cr (VI) onto the surface of the Fe-NPs is endothermic and spontaneous.

The Antibacterial Activity of Ginkgo Biloba Extract and Its Green Synthesis of Iron Nanoparticles

Background: The ancient plant species ginkgo biloba is thought to provide numerous health benefits to all living creatures. This plant is very bioactive and has a wide range of chemical constituents. There are several proven pharmacological and therapeutic benefits of G. biloba. Objective: The objectives of the present study were to produce iron nanoparticles (FeNPs), isolate a natural compound from Ginkgo biloba leaves, and evaluate the antibacterial properties of the resultant nanoparticles (NPs). Materials and Methods: Five extracts of Ginkgo biloba leaves were produced through various methods: cold water extraction, hot water extraction, cold alcoholic extraction, hot alcoholic extraction, and 70% alcoholic extraction. FeNPs biosynthesis occurred by reacting these Ginkgo biloba leaf extracts with iron sulfate Fe2 (SO4)3. Analysis techniques employed included GC/MS, SEM, XRD, and UV-Vis analysis. Results: The iron nanoparticles (FeNPs) utilized in this using scanning electronic microscopy measurement and UV-VIS spectroscopy, which has a characteristic peak at 217nm, it was possible to detect irregular structures with dimensions of no more than 41 nm. AFM was also used in this study to examine the NPs-Fe's size and morphology. The FTIR measurement also revealed the principal iron oxide bands at 685 and 596cm-1, which are caused by Fe-O vibrational stretching. Bioactivity was also carried out against certain bacteria. Conclusions: Antimicrobial activity showed an inhibiting effect on a variety of harmful bacteria. Klebsiella spp., Staphylococcus epidermidis and Candida albicans.

Fabrication of iron nanoparticles using different bioactive precursors, their characterization and bioactivity evaluation

This study deals with the green synthesis of Iron nanoparticles (FeNPs) using plant extracts of Polygonum plebeium (Knotweed) and Camellia sinensis (Green tea), focusing on their antibacterial potential, biocatalytic action as well as prospective applications as nanofertilizers. Plant materials underwent a thorough cleaning and were processed into aqueous extracts. The synthesis of FeNPs involved blending these extracts with ferric chloride solution, resulting in a versatile nanomaterial that was subjected to various characterization techniques, such as UV-Vis spectroscopy, FT-IR, XRD, SEM, and DLS-Zeta unveiling critical nanoparticle attributes of the synthesized nanoparticles, including the size, crystallinity, morphology, stability, and elemental composition. The synthesized FeNPs exhibited substantial antibacterial activities, against Escherichia coli and Staphylococcus aureus. Additionally, the biocatalytic properties of the synthesized FeNPs were investigated through dye degradation. These nanoparticles further, were demonstrated for their potential as nanofertilizers, enhancing the germination and growth of tomato and radish seeds. The merging of nanotechnology and plant-based synthesis represents a promising intersection with the capacity to revolutionize diverse fields.

A novel approach for the green synthesis of iron nanoparticles using marigold extract, black liquor, and nanocellulose: Effect on marigold growth parameters

This study aimed to investigate a novel method for the green synthesis of iron nanoparticles (FeNPs) using marigold extract (Calendula officinalis L), kraft pulping black liquor, and nanocellulose. Then, the efficacy of FeNPs as a direct nanofertilizer on the growth parameters of marigold was investigated. Characterization techniques including FESEM, EDX, VSM, and FTIR were used to confirm the successful synthesis of FeNPs. The characterization results confirmed the formation and presence of FeNPs in the 20–100 nm range. FeNPs synthesized with nanocellulose notably enhanced marigold growth parameters compared to other materials. However, all nanoparticle variants, including those from marigold extract and black liquor, improved germination, plant height, root length, and plant dry weight compared to the control. Moreover, treatments exhibited higher available iron and total plant iron levels than the control. Thus, employing 10 mg FeNPs (prepared with 5.0 % nanocellulose) appears optimal for enhancing marigold growth and yield.

An approach for cationic dyes removal from wastewater: Green synthesis of iron nanoparticles using Prunus avium stems extracts

Metallic nanoparticles with optical, electrical, catalytic, magnetic, and biological properties are structures that can be used in environmental pollution. The use of iron nanoparticles in environmental rehabilitaion is gaining interest due to their large surface area to volume ratio. The aim of this study is to synthesize and characterize iron oxide nanoparticles by using cherry plant extracts through a green synthesis approach, and to evaluate the use of cherry plant extracts as an adsorbent of methylene blue in wastewater. The physicochemical characterization of nanoparticles was performed with UV–Vis, FT-IR, XRD spectroscopies, SEM microscopy and Zetasizer particle size analysis. As a result of the experiments, the adsorption percentage increased depending on the time and 67.34% methylene blue removal was achieved at the 150th minute. This study highlights the importance of innovative approaches and the increasing use of biocompatible, environmentally friendly, and economical green materials in applications.

Green synthesis of iron nanoparticles from the baru (Dipteryx alata) endocarp extract for the efficient removal of rhodamine B and caffeine from water through the heterogeneous Fenton process

Abstract This study presents the first-time synthesis of iron nanoparticles (FeNPs) using an aqueous extract from the baru fruit endocarp (Dipteryx alata). Characterization through scanning electron microscopy and dynamic light scattering revealed spherical shapes with an average diameter of 419.2 nm. Fourier transform infrared spectroscopy identified phytochemicals from the baru fruit extract, acting as both reducing and stabilizing agents. X-ray diffraction confirmed the amorphous nature of the FeNPs. The Fenton-like catalytic efficiency of FeNPs was investigated for degrading rhodamine B (RhB) and caffeine. The impact of crucial parameters such as pH, H2O2 dosage, nanoparticles concentration, and temperature on the degradation process was assessed. At pH 3.0, with 1.0 g L−1 of FeNPs, 1% H2O2, and 45 °C, RhB and caffeine degradation reached 99.14 and 92.01%, respectively. The catalytic reaction kinetics followed a pseudo-first-order model for caffeine and a pseudo-second-order model for RhB. Phytotoxicity studies on Cucumis sativus confirmed the non-toxic nature of the degraded products of RhB and caffeine. These findings highlight the potential of FeNPs synthesized from the baru endocarp extract as a catalyst for removing organic pollutants, suggesting promising applications in environmental remediation and related fields.

Green synthesis of iron nanoparticles using mulberry leaf extract: characterization, identification of active biomolecules, and catalytic activity.

The synthesis of iron-based nanoparticles (Fe NPs) using traditional preparation methods suffered from the disadvantages of high cost, environmental harm, and easy agglomeration. In this study, a novel eco-friendly method was proposed for the synthesis of iron nanomaterials (ML-Fe NPs): using antioxidant components extracted from mulberry leaf to reduce divalent iron (II). The preparation conditions of ML-Fe NPs were optimized by orthogonal tests. The prepared ML-Fe NPs exhibited an amorphous core-shell structure, displaying excellent dispersion and stability. During the synthesis process of ML-Fe NPs, the polyphenol molecules in mulberry leaf extract played a dominant role. A possible synthetic mechanism involving complexation, reduction, and encapsulation was proposed. Furthermore, the ML-Fe NPs were utilized to construct an ML-Fe NPs/peroxymonosulfate catalytic system for the degradation of Rhodamine B dye wastewater. The ML-Fe NPs demonstrated remarkable catalytic potential, achieving a 99% degradation efficiency for Rhodamine B within a span of 40min.

Optimization and chemical free fabrication of green synthesized iron nanoparticles as potential MRI contrast agent.

The current research article has investigated the synthesis and characterization of novel iron nanoparticles (INPs) from neem and betel leaves extract combination using response surface methodology-central composite design and coated with chitosan-curcumin (CCINPs) as a biocompatible and contrast agent for magnetic resonance imaging (MRI). The coating of INPs with chitosan and curcumin (CCINPs) was carried out using a simple, easy, chemical-free ultrasonication method and characteristics were confirmed by UV-visible (Vis) spectrophotometer (UV-Vis), Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, atomic force microscopy, and vibrating sample magnetometer. The biocompatibility of the particles was ensured by conducting hemolytic and cell viability assays. The nanoparticle was found to be nonhemolytic (<5%) up to 150μg/mL for both INPs and CCINPs. The cell viability was stable (peripheral blood mononuclear cells-PBMCs) till 48h at 150μg/mL of INPs and CCINPs. Both the test results produced were found to be biocompatible and additionally, an in vitro MRI study of INPs and CCINPs demonstrated the efficiency of the nanoparticle as a negative contrast agent with enhanced contrast nature in CCINPs. Thus, overall results indicate that the green synthesized chemical-free novel CCINPs could be a potential candidate for a wide range of applications such as MRI, drug delivery, and in magnetic fluid hyperthermia.

Synthesis of Green Iron Nanoparticles Using Henna Plant Extract for Seed Germination and Vegetative Growth of Trigonella foenum-graecumL

This paper presents the green synthesis of iron nanoparticles (FeNPs). Iron sulfate served as the substrate and henna extract as the reducing agent in the synthesis of FeNPs. FeNPs were analyzed using a variety of techniques, including UV-visible spectroscopy, nano zeta-sizer analysis, and Fourier transform infrared spectroscopy (FTIR). By using UV-visible spectroscopy, the electron transition band of iron oxide, or the peak at 291 nm, was found to be the source of the FeNPs. The characteristic bands of iron oxide were detected at 790 by FTIR. These bands are associated with the stretching vibration of Fe-O at 1022 and 1516 cm-1. to determine how applying different combinations of nano-fertilizers affects the growth and yield of fenugreek. The experiment consisted of nine treatments. The results demonstrated that T8 performed better than the other treatments in terms of all elements of vegetative development and yield contents. The T8 yields plant height of 43.12 cm, fresh weight of 30.41g, dry weight of 2.44g, seed weight of 5.09g, and pod weight of 7.39g with an increase rate of (55.56, 82.97, 162.36, 105.24, and 122.59)%.

Green synthesis of iron nanoparticles using Syzygium aromaticum extracts and their applications: Nitrate removal, malachite green degradation and antibacterial activity

In recent years, the use of green synthesized nanoparticles has emerged as a promising approach to address the challenges associated with environmental pollution. The contamination of water resources, particularly the rise in nitrate and textile dye concentrations poses serious risks to both human health and aquatic ecosystems, promoting eutrophication. In this regard, the current study aimed to synthesize iron nanoparticles (FeNPs) from Syzygium aromaticum extract and characterize their physicochemical properties using various analytical techniques, including Scanning Electron Microscopy (SEM), UV–Visible (UV–Vis), Fourier Transform Infrared Spectroscopy (FT-IR), and X-ray Diffraction (XRD). The synthesized nanomaterials were then tested for their efficiency in removing nitrate and degrading the malachite green (MG) in aquatic systems. The batch experiments demonstrated that the green synthesized zero-valent iron particles (SA-FeNPs) and magnetite particles (SA-MNPs), using clove extract, removed 43 % and 36 % of nitrate, respectively, and degraded 29 % and 63 % of MG. These results suggest the feasibility of using green synthesized nanoparticles as a potential remediation strategy for addressing the issue of water pollution. Moreover, the nitrate removal and MG degradation by SA-FeNPs and SA-MNPs followed the pseudo-second-order adsorption model (∼R2 = 0.99) in the kinetic study. The findings of the study demonstrate the potential of green synthesized FeNPs for their effectiveness in removing nitrate and degrading MG in aquatic systems. Furthermore, the antibacterial activity of the synthesized FeNPs was evaluated against both gram-negative and gram-positive bacteria. The green synthesized FeNPs demonstrated good antibacterial activity, suggesting their potential to be used as an alternative material for developing effective antimicrobial agents. The results highlight the importance of green synthesis of FeNPs using Syzygium aromaticum extract as a sustainable approach for nitrate removal, MG degradation, and antibacterial activity in aquatic systems.

Mycogenic synthesis of iron nanoparticles using thermophilic mould Myceliophthora thermophila and their applicability in environmental remediation

Culture extract of thermophilic mould Myceliophthora thermophila BJTLRMDU7 played important role in the green synthesis of iron nanoparticles (FeNPs) using ferrous sulphate (FeSO4). The mould was grown in potato dextrose broth (PDB) at 45 °C and 200 rpm for 72 h. A colour change from transparent to reddish brown showed the synthesis of FeNPs due to the surface plasmon resonance by the fungal culture extract. The process for the synthesis of nanoparticles was optimized using different reaction conditions. Biogenic iron nanoparticles were synthesized maximally at 50 °C and pH 5.0 after 24 h using 2 mM salt solution and one ml culture extract. Furthermore, formation of iron nanoparticles was significantly accelerated in the presence of light. The absorption peak was maximum around 250–350 nm in UV–vis spectrum. The absorption peaks of Fourier-transform infrared spectroscopy (FTIR) at 619.99 cm−1, 793.57 cm−1, 882.32 cm−1, 1121.46 cm−1, 1627.71 cm−1, 2923.17 cm−1 and 3430.70 cm−1, indicated functional groups of active biomolecules involved in the synthesis of FeNPs. Atomic force microscopy (AFM) images of green synthesized iron nanoparticles indicated the average size of 80 nm, while X-ray diffraction (XRD) data revealed the crystalline nature of FeNPs. These FeNPs efficiently reduced p-nitrophenol (PNP) into p-aminophenol (PAP), which was further confirmed by thin layer chromatography. Biogenic FeNPs showed 96 and 35 % decolourization of bromphenol blue and malachite green, respectively. Further, addition of H2O2 enhanced the decolourization of malachite green up to 96 %. Biogenic FeNPs synthesized from culture extract of a thermophilic mould have been found effective in remediation of environmental pollutants released from various industries.

Accelerated Cr (VI) removal by a three-dimensional electro-Fenton system using green iron nanoparticles.

Green-synthesized iron nanoparticles (GAP-FeNP) were used as particle electrodes in a three-dimensional electro-Fenton (3DEF) process to accelerate the removal of hexavalent chromium [Cr (VI)]. Removal was evaluated by varying the pH (3.0, 6.0, and 9.0) and initial Cr (VI) concentrations (10, 30, and 50 mg/L) at 5 and 25 min. These results demonstrated that GAP-FeNP/3DEF treatment achieved more than 94% Cr (VI) removal under all tested conditions. Furthermore, it was observed that Cr (VI) removal exceeded 98% under pH9.0 in all experimental parameters tested. The results of the response surface methodology (RSM) determined two optimal conditions: the first, characterized by a pH of 3.0, Cr (VI) concentration at 50 mg/L, and 25min, yielded a Cr (VI) removal of 99.7%. The second optimal condition emerged at pH9.0, with Cr (VI) concentrations of 10mg/L and 5min, achieving a Cr (VI) removal of 99.5%. This study highlights the potential of the GAP-FeNP to synergistically accelerate Cr (VI) removal by the 3DEF process, allowing faster elimination and expansion of the alkaline (pH9.0) applicability. PRACTITIONER POINTS: The required time for >99% of Cr (VI) removal by the GAP-FeNP/3DEF process was shortened from 25 to 5min. EF process with GAP-FeNP reduces the time necessary for Cr (VI) removal, which is 67% faster than conventional methods. EF process using GAP-FeNP removed >94% of Cr (VI) after 25 min for all initial Cr (VI) concentrations and pH treatments. Cr (VI) removal by the GAP-FeNP/3DEF process was >98% at a pH of 9.0, widening the solution pH applicability.

Green synthesis of iron nanoparticles using Mangifera indica leaves extract: phytochemical analysis and characterizations, for environmental remediation of pollution

Green synthesis of iron nanoparticles using Mangifera indica leaves extract: phytochemical analysis and characterizations, for environmental remediation of pollution

Degradation of Malachite Green using Green Synthesized Iron Nanoparticles by &lt;em&gt;Coffea arabica&lt;/em&gt; Leaf Extracts and its Antibacterial Activity

The synthesis of biocompatible nanomaterials using bio-renewable plant extract has emerged as a promising alternative to traditional methods in recent years due to its cost-effectiveness, eco-friendliness, non-toxicity, and biocompatibility. In this research paper, we demonstrate using Coffea arabica leaf extract to synthesize zero-valent iron nanoparticles (GC-FeNPs). This study suggests that this method is efficient and environmentally friendly, making it a promising approach for developing biocompatible nanomaterials. The synthesized GC-FeNPs were characterized using Fourier-Transform Infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM), and UV–Vis spectroscopy techniques. According to the analysis of data, polyphenolic/caffeine compounds in the coffee leaf extract act as reducing/capping agents by converting the Fe2+ to Fe0, and minimizing the aggregation. The FT-IR and XRD data confirm the encapsulation of the GC-FeNPs by the polyphenolic/caffeine compounds in the coffee leaf extract. The GC-FeNPs have a quasi-spherical shape morphology with a particle size of about 80 – 100 nm. Further, dye degrading ability, and the antibacterial activity of the GC-FeNPs were investigated using malachite green (MG) and gram-negative and gram-positive pathogens. Experimental data revealed that GC-FeNPs (~ 20 ± 1 mg) showed degradation activity against MG up to 55 % upon the 120-minute incubation. Furthermore, the kinetic analysis of GC-FeNPs on MG degradation was in accordance with the pseudo-second-order kinetic model (R2 = 0.9922). In addition, GC-FeNPs showed an antibacterial activity against gram-negative (E. coli, and S. enterica), and gram-positive (S. aureus) pathogens. The E. coli growth was highly inhibited by the GC-FeNPs compared to other strains. Overall, GC-FeNPs facilitate an alternative approach to degrade MG from textile effluents and industrial wastewater and treat the pathogen-contaminated water.

Sustainable and Green Synthesis of Iron Nanoparticles Supported on Natural Clays via Palm Waste Extract for Catalytic Oxidation of Crocein Orange G Mono Azoic Dye.

In this study, the removal of Crocein Orange G dye (COG) from aqueous solution was investigated using an innovative green catalyst to overcome problems with chemical techniques. Clay bentonite El Hamma (HB)-supported nanoscale zero-valent iron (NZVI) was used as a heterogeneous Fenton-like catalyst for the oxidation of harmful COG. Palm waste extract was herein used as a reducing and capping agent to synthesize NZVI, and HB clay was employed, which was obtained from the El Hamma bentonite deposit in the Gabes province of Tunisia. HB and HB-NZVI were characterized by various techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer, Emmett, and Teller (BET), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), X-ray diffraction (XRD), and zeta potential. Under optimal conditions, total degradation of COG was attained within 180 min. Kinetic studies showed that the dye degradation rate followed well the pseudo-second-order model. The apparent activation energy was 33.11 kJ/mol, which is typical of a physically controlled reaction. The degradation pathways and mineralization study revealed that the adsorption-Fenton-like reaction was the principal mechanism that demonstrated 100% degradation efficiency of COG even after three successive runs. Obtained results suggest that HB-NZVI is an affective heterogeneous catalyst for the degradation of COG by H2O2 and may constitute a sustainable green catalyst for azoic dye removal from industrial wastewaters.

Larvicidal activity of green synthesized iron oxide nanoparticles using Grevillea robusta Cunn. leaf extract against vector mosquitoes and their characterization

Extensive fumigation of synthetic pesticides to control the mosquito vector during each post-monsoon season in Pakistan significantly enhanced the environmental contamination and extinction of beneficial insects from the urban ecosystems. In this context, the present study examined the larvicidal efficacy of green synthesized iron nanoparticles (IONPs), using an aqueous leaf extract of Grevillea robusta against the early 2nd and 4th instar larvae of Aedes aegypti and Anopheles stephensi in Pakistan. The prepared IONPs were characterized by UV–Vis spectrum, FTIR, X-ray diffraction, scanning electron microscopy, and energy-dispersive diffraction. Larvicidal bioassay was conducted at various concentrations (80, 160, 240, 320, and 400 ppm) of IONPs prepared from leaf extract of G. robusta, and readings were taken-every 12 h for two consecutive days. In vitro, larvicidal assay, G. robusta leaf extract IONPs exhibited high mortalities of 64–96% (LC50 = 259.07 ppm; LC90 = 443.92 ppm) for the second instar and 65–98% (LC50 = 238.05 ppm; LC90 = 433.93 ppm) for the fourth instar of Ae. aegypti, while in the case of An. stephensi 56–84% (LC50 = 297.96 ppm; LC90 = 528.69 ppm) for the second and 56–88% (LC50 = 292.72 ppm; LC90 = 514.00 ppm) mortality for fourth larvae at 12–48 h post-exposure times were observed respectively. Significant (p < 0.05) dose-dependent and exposure time-dependent trends were observed among the 2nd and 4th larvalinstar of An. stephensi and Ae. aegypti. However, both species showed similar response and observed no significant (p > 0.05) difference in percentage mortality between the vector mosquitoes An. stephensi and Ae. aegypti. Overall, this study demonstrates that the larvicidal efficacy of green synthesized IONPs at low concentrations can be an ideal eco-friendly and cost-effective biocontrol of vector mosquitoes' larvae of An. stephensi and Ae. aegypti.

Potential of plant mediated biosynthesis of iron nanoparticles and their application in dye degradation process

ABSTRACT In recent years, nanotechnology has emerged as cutting-edge technology with multifarious applications in a wide array of fields. Green synthesis of iron nanoparticles (FeNP) are an upcoming cost effective and eco-friendly technique and recently gained significant importance. In the present study, green FeNPs were prepared using leaf litter which is one of the major seasonal waste contributors in urban built-up areas. Shedding trees during winter months (January – March) were selected. Most abundant trees were Pongamia pinnata (Indian beech), Morus alba (mulberry), Prosopis juliflora (mesquite) and Kigelia africana (sausage tree). Synthesized FeNPs were further used for degrading two commercial dyes, eosin yellow and fuchsin basic, via Fenton’s mechanism. The study showed that the prepared nanoparticles were of iron oxides, but also reported presence of polyphenols as a capping agent. Dye degradation efficiency of nanoparticles synthesized by P. pinnata leaf litter was recorded to be highest, whereas the efficiency of nanoparticles synthesized by K. africana leaf litter was lowest. Chances of iron leaching during dye degradation process was also tested and observed that Fe was present in treated water below the standard guidelines. Thus, FeNPs can serve as a low-cost solution to remediate water pollutants with a green approach. Implications: Nanoparticles prepared in the study were showed as a promising adsorbent and demonstrating high surface area and well-developed porosity. The prepared adsorbent will have a great impact on wastewater treatment technology and possible applications at a large scale. There are several applications of nanoparticles in pollution remediation and at the same time it can solve solid waste issues as it required to prepare nanoparticles. One of the major applications at policy level can be water pollution remediation which is urgently needed.