Iron Chloride Solution Research Articles

Some physicochemical properties of aluminum and iron chloride solutions

Some physicochemical properties of aluminum and iron chloride solutions are considered. The density and viscosity of aluminum and iron chlorides are plotted as functions of the FeCl3/(FeCl3 + AlCl3) ratio and temperature, and pH of aluminum hydroxochlorides is plotted as a function of the Al2O3 content in a solution and its basicity (ratio of contents Al/Cl). The joint solubility of aluminum hydroxochloride and sodium chloride in water has been analyzed.

Removal of Phosphate from Aqueous Solution Using Alginate/Iron (III) Chloride Capsules: a Laboratory Study.

Binding phosphate at participation of alginate/FeCl3 capsules was studied with laboratory experiments. The hydrogel microcapsules were obtained with the dropping-in method, by gelation of sodium alginate water solution by iron (III) chloride solution. Phosphate adsorption characteristics were studied in a static batch system with respect to changes in contact time, initial phosphates concentration, pH of solution, and temperature. After 24 h of the tests, average 87.5% of phosphate ions were removed from the natural water solutions; after 48 h, an equilibrium was reached. The adsorption data were well fit by the Freundlich isotherm model. Parameter k of the isotherms amounted from 43.4 to 104.7, whereas parameter n amounted from 0.362 to 0.476. The course of processes of phosphate adsorption and iron desorption to aquatic phase, as well as changes in pH, suggests that phosphate adsorption is a major mechanism of phosphate removal, whereas simultaneously, but at a much lower degree, a process of precipitation of phosphate by iron (III) ions released from the capsules to the solution takes its place. Parameters calculated in the Freundlich isotherm equation show that by using several times smaller amounts of iron, it is possible to remove similar or bigger amounts of phosphorus than with other adsorbents containing iron. The alginate/FeCl3 adsorbent removes phosphate in a wide pH spectrum—from 4 to 10. Results suggest that the proposed adsorbent has potential in remediation of contaminated waters by phosphate.

ПЕРСПЕКТИВИ ЗАСТОСУВАННЯ ЧУБУШНИКА ЯК ЛІКАРСЬКОЇ РОСЛИНИ

Medicinal plants are insufficiently studied and almost endless. The use of phytomedication enables reduce the impact of xenobiotics on animals organism through the natural origin of active compounds and associated and auxiliary substances smoothing the basic action and prevent the manifestation of side effects. One of such plants the possibility of using in veterinary practice is still insufficiently studied is mock–orange. Considering on the important role of phenolic compounds in the metabolic regulation of plant and diversity of impact of these substances on organism of animals and humans, in leaves of mock–oranges different cultivar was identified the content of phenolic secondary metabolites to identify the prospects for their further using in veterinary medicine. The qualitative reaction with the Wilson reagent, solution of iron (III) chloride and by cyanidin reaction in extracts from mock–orange leaves was established the presence of phenolic compounds. Further phytochemical investigations established that the content of phenols in the investigated extracts is between 33.0 ± 0.48 to 107.1 ± 0.91 mg/g (in Philadelphus L. 'Avalanche'). The content of flavonoids in alcohol extracts from leaves of different species of mock–oranges varies from 5.3 ± 0.41 to 10.6 ± 0.41 mg/g. Greatest quantity of flavonoids at relatively of low content of phenols contained in the preparation from leaves of Philadelphus coronaries 'Nana '(mock–orange dwarf), the use of which, along with Philadelphus L. 'Avalanche' can be perspective in medical and veterinary practice, considering on the high concentration of phenols and flavonoids and coumarins in these mock–oranges breed.

Effects of Hydrogen on Corrosion Products Formed on Iron in Chloride Solutions

The effects of charged-hydrogen on the properties of the surface films formed on iron after 21 h immersion in pure water and 10-4 to 0.5 mol/L NaCl solutions at 25 °C are investigated by open circuit potential (OCP) measurements, optical microscope, Raman spectroscopy and X-ray diffraction (XRD). Hydrogen-charging favors the formation of with dark film with yellow corrosion sites on iron. After immersion in 10-4 mol/L NaCl solution, the non-charged iron is partly covered by surface film, while the hydrogen-charged iron is fully covered by surface film. After immersion in 0.5 mol/L NaCl solution, the surface of the non-charged iron is partly dark and partly covered with yellow rusts, and the surface of the hydrogen-charged iron has a larger area covered with yellow rusts than that on the non-charged iron. OCP values for hydrogen-charged iron in pure water, 10-3 and 10-4 mol/L NaCl solutions are lower than those for non-charged iron. In 0.5 mol/L NaCl solution, the OCP difference between non-charged iron and hydrogen-charged iron is at first large and gradually becomes smaller with increasing immersion time. Raman spectra and XRD patterns show the presence of magnetite in the film on hydrogen-charged iron after immersion in 10-4 mol/L NaCl solution. In solutions with a high chloride concentration, hydrogen in iron can promote the formation of high valence iron oxide layer by precipitation.

Conductive nanocomposites based on TEMPO-oxidized cellulose and poly(N-3-aminopropylpyrrole-co-pyrrole)

In this paper, conductive composite films were synthetized based on oxidized cellulosic nanofibres (CNFo), 1-(2-cyanoethyl)pyrrole and pyrrole. The 1-(2-cyanoethyl)pyrrole was reduced into N-(3-aminopropyl)pyrrole before being grafted on carboxyl groups of CNFo. Oxidative polymerization of polypyrrole (Ppy) was conducted in an iron(III) chloride (FeCl3) solution, onto the N-(3-aminopropyl)pyrrole grafted. The resulting composite films were characterized by FTIR-ATR Spectroscopy, scanning electron microscopy (SEM) equipped with energy-dispersive x-ray spectroscopy (EDX), tensile strength measurement, thermogravimetric analysis (TGA), wettability and electrical conductivity measurements. The grafting of 1-(2-cyanoethyl)pyrrole played a leading role in improving these properties by increasing potential connections between chains of conducting polymer and cellulose fibres. The outcomes show that the PPy nanoparticles coating on the grafted films increase a lot of characteristics of our composite such as wettability, mechanical properties, thermal protection and more importantly the electrical conductivity which was improved by a 10E5 factor in comparison to the uncoated films. In this condition, this nanostructure could be considered in the design of high-performance electrodes for supercapacitor, battery and sensor applications.

Properties of Ferrofluids Prepared with an Isoparaffin Base.

Magnetite nanoparticles were synthesized by adding ammonium hydroxide to an iron chloride solution. An unsaturated oleate surfactant was adsorbed on the magnetic particles, and a nonionic Span 20 surfactant was applied onto the oleate-adsorbed particles to form a bilayer structure. The bilayer nanoparticles formed stable dispersions with isoparaffin as the liquid base. The experimental parameters were determined at each concentration to prepare isoparaffin-based ferrofluids with concentrations of 200, 300, 400 and 500 mg/mL; these were characterized by density, dispersion, magnetization and viscosity. The density of the fluids increased in proportion to the concentration from 0.93 g/mL to 1.22 g/mL, whereas the dispersion stability decreased from 97% to 69% with increasing ferrofluid concentration. The saturation magnetization of the ferrofluids depended upon the content of particles in the fluid, with values of 17.8 to 42.2 mT at the concentrations of 200 to 500 mg/mL, respectively. The fluid viscosity increased exponentially with the concentration increase in the same range, from 5.1 cP to 53.7 cP at 20 degrees C and from 3.2 cP to 25.6 cP at 40 degrees C.

Structural and Magnetic Properties of Fe Films Electrodeposited on Al Substrates

Series of Fe films have been prepared by electrodeposition in a solution of iron chloride onto Al substrate. Different deposition times were used in the elaboration process. The texture, the strain, and the grain size values were derived from X-ray diffraction experiments. Scanning electron microscopy (SEM) has been used to get the surface and the cross section images. Vibrating Sample magnetometer has been used to obtain the hysteresis curves; the external magnetic field was applied in different directions in the film plane, and also perpendicular to the film. Hysteresis curves have been obtained at low temperatures [120 K (−153 °C) to room temperature]. The 〈100〉 texture, small strain, and grain size ranging from 58 to 113 nm are found for these Fe/Al films. All samples show an in-plane magnetic anisotropy, with no preferred orientation within the film plane. Depending on the film thickness range, different mechanisms have been found to be responsible for the coercive field H C behavior. These magnetic properties are correlated with the structural ones and with the SEM observations.

Experimental support for new electro active repair method for reinforced concrete

This paper, describes experiments that form the basis of an invention that aims at improving the durability of conventional (mechanical) repairs to concrete structures suffering from chloride induced corrosion of reinforcing steel. The invention comprises application of a short term, low voltage, DC current before or after concrete is broken out and before repair material is applied. It is an additional step in conventional concrete repair. The application of current will last typically 24 h at a current density of typically 5 A/m2 of steel surface area. In laboratory experiments corrosion pits are simulated by placing highly concentrated iron(II)chloride solution in contact with a mortar surface, after which current is applied. The results indicate that this treatment is able to remove 90% or more of the chloride from the simulated pit solutions. Furthermore, the pH has increased from about 3 to more than 12. The combined reduction of chloride content and increase of pH strongly reduces the chloride to hydroxyl ratio of the pore solution and thus the aggressive conditions at the reinforcing steel. After applying alkaline chloride free repair material, this will result in a longer life of the repair, thus reducing the life cycle costs of repaired structures. The process is named EAR, electro active repair.

Effects of a Magnetic Field on Anodic Dissolution and Surface Morphology of Iron in a Chloride Solution with Nitrite Ions

The corrosion of metallic materials in industrial and natural environments,especially localized corrosions such as pitting corrosion, crevice corrosion and stress corrosion cracking, caused huge damage. Some metallic components servicing in corrosive environments can be affected by magnetic fields produced by the special electrical equipment nearby. To analyze and evaluate the corrosion behavior under magnetic field, it is necessary to understand the effect of magnetic field on uniform and localized corrosion. In this study, the effects of a 0.4T magnetic field on the electrochemical behavior and corrosion morphologies of iron in chloride solutions with sodium nitrite ions were studied by optical microscope (OM), scanning electron microscope (SEM) and several electrochemical methods such as potentiodynamic polarization curve, potentiostatic polarization and electrochemical impedance spectroscopy, Potentials in different regions of the anodic polarization curves were chosen to for potentiostatic polarization by applying or removing a 0.4T magnetic field. The current density vs. time curves were measured, as shown in Fig. 1. The impact of magnetic field on the surface morphology of the electrodes after potentiostatic polarization were observed. The anodic current density increased with increasing polarization potential with or without a 0.4T magnetic field. The current density was very low in the passivation regions during potentiostatic polarization, which was reduced by the applied magnetic field, as shown in Fig. 1 a. The effect of the applied magnetic field on the the current density in near the passivation-transpassive transition potential was complex. The applied magnetic field increased the anodic current density under high potentials such as 0.4 V(SCE), as shown in Fig. 1 b. The changing of pit number and area for iron in chloride solutions with sodium nitrite with polarization potential exhibited differences with or without 0.4 T magnetic field. The impact of magnetic field on the pitting corrosion is closely related to the polarization potentials, polarization time and the initial state of the electrode surface. Figure 1

The Effects of Hydrogen on Corrosion Products Formed on Iron in Chloride Solutions

The effects of charged hydrogen on the properties of the surface films formed on iron in pure water and 10-4 to 0.5 mol/L NaCl solutions at 25°Cwere investigated by open circuit potential (OCP) measurements, optical microscope, scanning electron microscope and X-ray diffraction (XRD). After 21h immersion in pure water, the surface of non-charged iron did not significantly and showed only local corrosion sites, while the surface of hydrogen-charged iron was covered with dark film with many yellow corrosion sites on it. After 21h immersion in 10-4 mol/L NaCl solution, the non-charged iron was partly covered by surface film, while the hydrogen-charged iron was fully covered by surface film, as shown in Fig. 1. After 21h immersion in 0.5 mol/L NaCl solution, the surface of the non-charged iron was partly dark and partly covered with yellow rusts, and the surface of the hydrogen-charged iron had a larger area covered with more yellow rusts than that on the non-charged iron, as shown in Fig. 2. Results of OCP monitoring showed that OCP values for hydrogen-charged iron in pure water, 10-3 and 10-4 mol/L NaCl solutions were lower than those for non-charged iron, as partly shown in Fig. 3a. In 0.5 mol/L NaCl solution, the OCP differences between non-charged iron and hydrogen-charged iron was at first big but gradually became smaller with increasing immersion time, as shown in Fig. 3b. Raman spectra showed the presence of magnetite in the film on hydrogen-charged iron after immersion in 10-4 mol/L NaCl solution, as shown in Fig. 4a, which was supported by XRD results. Yellow rust and the XRD peak for hematite in the films on non-charged and hydrogen iron specimens (Fig. 4) indicated that the mechanism for the effect of hydrogen on the corrosion products of iron in dilute NaCl solutions could be different from that in concentrated NaCl solutions. In solutions with a high chloride concentration, hydrogen in iron might be able to promote the formation of high valence iron oxide, while in many other cases it was found that the formation of magnetite was promoted by hydrogen in iron. Figure 1

Preparation of Graphene Encapsulated Silicon Nanoball.

Concerning application of graphene, a lot of efforts have been made to improve performance of nanomaterials in many fields, such as electric and electronic devices. Some examples are preparation of 3-dimension structured nanomaterials like nanoballs by CVD process and hybridizing with silicon. These graphene-based materials are proven to be available for secondary battery, EMI and ACF in electronics. Especially, some research has shown that they were very effective to enhance safety and volumetric capacity when they were used as anode materials of secondary battery. Although graphite and its compound with metal have been used as an anode material due to their high stability and reversibility, it still has lower charge capacity. On the contrary, silicon is known as a material which increases the charge capacity up to four times, compared with carbon-based materials, but it has lower stability and reversibility. For that reason, a few researchers just started to improve the charge capacity by hybridization of carbon-based material with silicon. In this paper, we prepared nanocarbon based material which has a new structure of graphene encapsulated silicon nanoball as an anode material which is applicable to high-capacity secondary battery. In order to form a graphene encapsulated silicon nanoballs, the polystyrene encapsulated silicon nanoballs were prepared by emulsion polymerization of styrene monomer with silicon nanoparticles. The resulting nanoballs were immersed in iron chloride solution and then dried. Finally they were treated in high temperature through CVD and etched by hydrogen chloride. Morphology of the graphene encapsulated silicon nanoballs was observed by the field emission scanning electron microscope (FESEM) and the field emission transmission electron microscope (FETEM) to search for core-shell structured nanoball. Spherical structure of graphene encapsulated silicon nanoball was investigated by the Raman, the X-ray Photoelectron Spectroscopy to identify graphene layers on the surface of the inner silicon core.

Synthesis of Nylon-ferrous Oxide Chitosan Immobilised Silica Nanoprobe for Detection of Ralstonia solanacearum

Accurate detection of plant pathogen precedes control. Misdiagnosis of diseases results in chemical waste, crop damage and ultimately income loss. Precision in pathogen detection has been made possible by advances in plant pathology, biotechnology and nanotechnology. For instance, PCR and fluorescent kits have been developed to detect diseases. On-farm utilisation of Original Research Article Maina et al.; JAERI, 7(4): 1-17, 2016; Article no.JAERI.23845 2 the aforementioned technologies has been limited by the expertise required and cost. Colorimetric nanoprobes have been applied in detection of water pathogens and heavy metals. This study entailed development of nylon-ferrous oxide chitosan-silica nanoprobe for Ralstonia solanacearum pathogen. Electrospun nanofibres were used as support for ferrous oxide chitosan immobilised silica nanocomposite (FeOCISNC) gel. The materials were selected due to their compatibility, large surface area for microbial adsorption and high affinity of iron by R. solanacearum bacteria. Optimisation experiments were carried out to determine the concentration of components and pH that yielded highest iron oxide nanoparticles (FeONPs). There was significantly high yield (P=.05) when a ratio of 2:3 (v/v) for green tea extract to iron chloride solution and a pH of 6 were used. Synthesised composites were characterised using X-ray powder difraction (XRD). The resulting nanomaterials had crystallite sizes of 3.96, 5.00 and 11.60 nm for FeONPs, FeOCISNC and nylonFeOCISNC respectively. Detection of R. solanacearum was marked by colour change from grey to brown in the presence of the isolated pathogen. This was also corroborated by XRD characterisation; the nanoprobe adsorbed pathogen had a crystallite size of 14.75 nm. Additionally, the time required for optimal adsorption of FeOCISNC gel and pathogen suspension on the nylon nanofiber and nylon-FeOCISNC probe respectively was determined using optical density (O.D) of the suspensions after adsorption. There was no significant difference (P=.05) in the O.D of FeOCISNC gel when nylon nanofibres were immersed for 8 hr, 16 and 48 hr. Also, the O.D of the pathogen suspension was not significantly different (P=.05) after 5, 30 and 60 min which validated the observation that the change in colour intensity from grey to brown on the nanoprobe was not visually different within the time period. The colour change was attributed to the disruption of the pathogen membrane by glucosamine units in chitosan followed by complexation, absorption and reduction of iron oxide. Absorption of iron from the nanocomposite was due to the high affinity for iron by the bacteria. It can be concluded that, the combination of ferrous oxide and chitosan silica nanocomposites gel produced a rapid, precise and user friendly tool for detection of the lethal pathogen. The precise detection will consequently form the basis for the pathogen control.

Macroscopic Graphene Fibers Directly Assembled from CVD-Grown Fiber-Shaped Hollow Graphene Tubes.

Using a copper wire as the substrate for the CVD growth of a hollow multilayer graphene tube, we prepared a macroscopic porous graphene fiber by removing the copper in an aqueous mixture solution of iron chloride (FeCl3, 1 M) and hydrochloric acid (HCl, 3 M) and continuously drawing the newly released graphene tube out of the liquid. The length of the macroscopic graphene fiber thus produced is determined mainly by the length of the copper wire used. The resultant macroscopic graphene fiber with the integrated graphene structure exhibited a high electrical conductivity (127.3 S cm(-1)) and good flexibility over thousands bending cycles, showing great promise as flexible electrodes for wearable optoelectronics and energy devices-exemplified by its use as a flexible conductive wire for lighting a LED and a cathode in a fiber-shaped dye-sensitized solar cell (DSSC) with one of the highest energy conversion efficiencies (3.25%) among fiber-shaped DSSCs.

Macroscopic Graphene Fibers Directly Assembled from CVD‐Grown Fiber‐Shaped Hollow Graphene Tubes

AbstractUsing a copper wire as the substrate for the CVD growth of a hollow multilayer graphene tube, we prepared a macroscopic porous graphene fiber by removing the copper in an aqueous mixture solution of iron chloride (FeCl3, 1 M) and hydrochloric acid (HCl, 3 M) and continuously drawing the newly released graphene tube out of the liquid. The length of the macroscopic graphene fiber thus produced is determined mainly by the length of the copper wire used. The resultant macroscopic graphene fiber with the integrated graphene structure exhibited a high electrical conductivity (127.3 S cm−1) and good flexibility over thousands bending cycles, showing great promise as flexible electrodes for wearable optoelectronics and energy devices—exemplified by its use as a flexible conductive wire for lighting a LED and a cathode in a fiber‐shaped dye‐sensitized solar cell (DSSC) with one of the highest energy conversion efficiencies (3.25 %) among fiber‐shaped DSSCs.

Into the groove: instructive silk-polypyrrole films with topographical guidance cues direct DRG neurite outgrowth

Instructive biomaterials capable of controlling the behaviour of the cells are particularly interesting scaffolds for tissue engineering and regenerative medicine. Novel biomaterials are particularly important in societies with rapidly aging populations, where demand for organ/tissue donations is greater than their supply. Herein we describe the preparation of electrically conductive silk film-based nerve tissue scaffolds that are manufactured using all aqueous processing. Aqueous solutions of Bombyx mori silk were cast on flexible polydimethylsiloxane substrates with micrometer-scale grooves on their surfaces, allowed to dry, and annealed to impart β-sheets to the silk which assures that the materials are stable for further processing in water. The silk films were rendered conductive by generating an interpenetrating network of polypyrrole and polystyrenesulfonate in the silk matrix. Films were incubated in an aqueous solution of pyrrole (monomer), polystyrenesulfonate (dopant) and iron chloride (initiator), after which they were thoroughly washed to remove low molecular weight components (monomers, initiators, and oligomers) and dried, yielding conductive films with sheet resistances of 124 ± 23 kΩ square−1. The micrometer-scale grooves that are present on the surface of the films are analogous to the natural topography in the extracellular matrix of various tissues (bone, muscle, nerve, skin) to which cells respond. Dorsal root ganglions (DRG) adhere to the films and the grooves in the surface of the films instruct the aligned growth of processes extending from the DRG. Such materials potentially enable the electrical stimulation (ES) of cells cultured on them, and future in vitro studies will focus on understanding the interplay between electrical and topographical cues on the behaviour of cells cultured on them.

Synthesis of carbon-encapsulated iron nanoparticles from wood derived sugars by hydrothermal carbonization (HTC) and their application to convert bio-syngas into liquid hydrocarbons

Carbon-encapsulated iron nanoparticles (CEIN)were prepared from a solution of Iron(II) chloride (FeCl2) and wood derived sugars under hydrothermal carbonization (HTC) conditions. The obtained nanostructures were characterized by SEM, TEM, HRTEM, XRD, TPD, Raman, and FTIR. The size of these nano-spheres was approximately 100–150 nm in diameter with an iron core diameter of 10–25 nm. The carbon-encapsulated iron nanoparticles were used as catalysts to thermochemically convert wood derived syngas into liquid hydrocarbons. These nanoparticles showed excellent catalytic performance when used as catalysts for the Fischer–Tropsch synthesis (FTS) process, and these nanoparticles showed high selectivity towards creating C5+ hydrocarbons. While undergoing reactions with biomass derived syngas at 290 °C, the CO conversion rate from this catalyst was found to be 89.5% and hydrocarbon selectivity was discovered to be 65%.

Comparative evaluation of five plant extracts and juices for nanoiron synthesis and application for hexavalent chromium reduction

The effectiveness of five plant extracts and juices, i.e. extracts of Camellia sinensis (green tea, GT), Syzygium aromaticum (clove, CL), Mentha spicata (spearmint, SM), Punica granatum juice (pomegranate, PG) and Red Wine (RW), for the production of nanoiron suspensions and their application for Cr(VI) reduction was investigated. Polyphenols contained in extracts act as reducing agents for iron ions in aqueous solutions, forming thus iron nanoparticles, and stabilize the nanoparticles produced from further oxidation and agglomeration. The maximum amount of polyphenols extracted per g of herbs was obtained at herb mass to water volume ratio varying from 10 to 20g/L. Suspensions of nanoparticles with sizes below 60nm were produced by mixing iron chloride solution with the plant extracts and juices investigated. The maximum concentration of nanoiron in suspensions was estimated to 22mM, obtained using RW and PG at a mixing ratio of iron solution to extract equal to 2. Lower concentrations, up to 18mM, were achieved using GT and CL extracts. Therefore, PG juice and RW were considered as more effective for nanoiron production, and, together with GT extracts, they were selected for the production of nanoiron suspensions, which have been proven effective for Cr(VI) reduction, reaching removal capacity as high as 500mg Cr(VI) per g of iron in nanoparticles.

Drying of Iron Chloride Solutions: Laser Heating of Levitated Single Particles

AbstractIron chloride solutions are a waste product from the steel industry, which has to be recovered by the so‐called spray roasting process. As this process is a complex sequence of different steps, the drying process of the droplets was separated to get deeper insight into the particle formation process from aqueous iron chloride solutions. Experiments were carried out on single droplets in an acoustic levitator. A CO2 laser was used as heat source for the drying process. Particles with different shapes were generated by various concentrations of FeCl2 and laser power. The characteristic time scales and particle size evolution are compared with literature data.

Creation of functional solid-state composites based on black peat

The paper presents investigations of composite materials based on black peats of Barabinskoe and Taganskoe deposits of the Tomsk region and carboxymethyl cellulose, both modified with iron (III) and copper (II) chloride solutions. In order to improve hydrophobic properties of compositions, optimum salt concentrations are detected. Water sorption and desorption isotherms are obtained for modified specimens. It is suggested to employ synthesized solid-state compositions as insulators in the capacity of both humidity controller and indoor-contaminant absorber.

Chlorococcum sp. MM11—a novel phyco-nanofactory for the synthesis of iron nanoparticles

Green synthesis of iron nanoparticles using a soil microalga, Chlorococcum sp. MM11, and their application in chromium remediation have been investigated. Spherical-shaped nanoiron was synthesized by treating the exponentially growing culture of Chlorococcum sp. with 0.1 M iron chloride solution for 48 h and incubating it under shaking in the dark. The appearance of a yellowish brown colour indicated the biotransformation of bulk iron into nanoiron. Morphological characteristics of nanoparticles with transmission electron microscopy (TEM) and dynamic light scattering (DLS) confirmed the presence of spherical-shaped nanoiron ranging in size from 20 to 50 nm. TEM imaging also revealed the localization of nanoiron on the microalgal cell surface, inside as well as outside the cell. Fourier transform infrared spectroscopy (FTIR) analysis confirmed the involvement of carbonyl and amine bonds from polysaccharides and glycoproteins present in the algal cell wall in the bioreduction as well as capping of nanoiron. Phyco-synthesized iron nanoparticles were tested for their efficiency in reducing Cr(VI), a toxic environmental pollutant. The results showed that nanoiron reduced 92 % of 4 mg L−1 Cr(VI) to Cr(III) instantaneously, while bulk iron reduced only 25 %. Thus, iron nanoparticles with high reactivity, greater stability and environmentally benign and economically viable properties can be synthesized using phyco-nanofactories like Chlorococcum sp. MM11.