Nickel Ferrite Nanocomposite Research Articles

Zinc oxide and nickel ferrite nanocomposite as an efficient photocatalyst for crystal violet dye degradation

In the present study, photocatalytic activity of NiFe2O4/ZnO nanocomposite was studied for the degradation of crystal violet dye. Microwave assisted green synthesis method was used for the synthesis of ZnO nanoparticles (NPs). Sol-gel auto-combustion method was used to synthesize NiFe2O4 (NiF) NPs. NiF/ZnO nanocomposite was synthesized through solid-state reaction method. Structural phase was confirmed through X-ray diffraction studies. ZnO NPs were found in wurtzite hexagonal structure whereas cubic spinel structure was found for NiF. NiF/ZnO nanocomposite was observed in both phases. The crystallite size was found to be 31 ± 1, 18 ± 2 and (95 ± 1)/(98 ± 1) nm, for NiF, ZnO and NiF/ZnO nanocomposite, respectively. The optical band gap was determined through UV–Visible spectroscopy and is found to be 1.67 ± 0.03, 2.70 ± 0.08 and 1.70 ± 0.05 eV for NiF, ZnO and NiF/ZnO nanocomposite, respectively. Infrared study of NiF showed the tetrahedral and octahedral band whereas for ZnO the characteristic band was observed. FESEM micrographs of NiF/ZnO nanocomposite showed the formation of agglomerated spherical particles and very less number of rod-like grains indicating the formation of NiF/ZnO nanocomposite. The photocatalytic activity of NiF, ZnO and NiF/ZnO nanocomposite for the degradation of crystal violet dye was studied. It was found that NiF, ZnO and NiF/ZnO nanocomposite showed 89 %, 90.46 % and 87.21 % degradation rate in 60, 120 and 50 min respectively.

Biomass-derived Activated Carbon with Nickel Ferrite Nanocomposite for Broadband Microwave Absorption

This study presents a novel approach using a composite material consisting of Biomass-derived Activated Carbon and Nickel Ferrite Nanocomposite as an advanced option for achieving effective microwave absorption over a wide range of frequencies. The use of biomass, which is a sustainable and easily accessible resource, serves as the fundamental basis for this methodology. This approach effectively tackles the need for enhanced electromagnetic interference shielding in communication and radar systems by integrating activated carbon generated from biomass with nickel ferrite nanoparticles. Traditional approaches often encounter challenges related to the limited absorption of bandwidth and environmental considerations. The utilization of Biomass-derived Activated Carbon for Broadband Microwave Absorption (BMAC-BMA) presents a significant advancement, characterized by a noteworthy Absorption Coefficient of 14.25 Np/m, Return Loss of -20.37 dB, specific surface area of 580.25 m²/g, pore size distribution of 2.8 nm, Saturation Magnetization of 1.35 A/m and Reflection Coefficient of 0.1. These characteristic holds promise for driving breakthroughs in technology and communication systems. This study demonstrates the significant impact of using sustainable biomass resources in producing advanced materials for various applications.

Amino acid functionalized metal oxide nanocomposite for the removal of fluoroquinolones

Antibiotic consumption has increased globally, and its discharge into water bodies at concentrations ranging from a few ng/L to mg/L has a detrimental effect on the ecosystems. Amino acid functionalized nickel ferrite nanoparticles were chosen to improve the stability of bare nanoparticles and prevent oxidation and leaching ions in nanoparticles thereby targeting the antibiotics in the contaminated water bodies. The removal of ciprofloxacin and lomefloxacin hydrochloride in the aqueous phase was investigated using a hydrothermally synthesized L-Leucine functionalized nickel ferrite nanocomposite (NFO@L). Various analytical techniques were used to analyze L-Leucine functionalized nickel ferrite, and the nanocomposite's average particle diameter was determined to be between 11 and 15 nm. The maximal measured zeta potential was −21.5 mV. Fourier transform infrared spectroscopy (FTIR), ninhydrin assay and X-ray diffraction (XRD) analysis confirmed the attachment of L-Leucine onto nickel ferrite. The nanocomposite's surface-to-volume ratio was calculated to be 92.916 m2/g. The S-shaped curve from the vibrating sample magnetometer analysis reflected the superparamagnetic behaviour of the nanocomposite with a saturation magnetization of 0.665 emu/g. Various parametric experiments were conducted, in which 93.549% ciprofloxacin was removed in 120 min at 303 K, pH 8 and NFO@L dosage of 100 mg in 100 mL whereas 75.192% lomefloxacin hydrochloride was removed in 140 min at 333 K, pH 9 and NFO@L dosage of 70 mg in 100 mL. The plot of experimental datum in kinetic and isotherm studies fitted well with the Pseudo second order kinetic model and Langmuir isotherm. There was no evidence of iron ions leaching from the final analyte. The recycle and regeneration studies showed good stability with a small reduction after four cycle runs. Based on these findings, the Leucine functionalized nickel ferrite nanocomposite could be a potent adsorbent for the removal of low-concentrated ciprofloxacin and lomefloxacin hydrochloride in the wastewater.

Synthesis and characterization of a novel magnetic chitosan–nickel ferrite nanocomposite for antibacterial and antioxidant properties

A novel nanomagnet modified with nickel ferrite nanoparticles (NPs) coated with hybrid chitosan (Cs–NiFe2O4) was synthesized using the co-precipitation method. The resulting nanomagnets were characterized using various techniques. The size of the nanomagnetic particles was estimated to be about 40 nm based on the transmission electron microscopy (TEM) image and X-ray diffraction analysis (XRD) pattern (using the Debye–Scherrer equation). Scanning electron microscopy (SEM) images indicated that the surface of Cs–NiFe2O4 NPs is flatter and smoother than the uncoated NiFe2O4 NPs. According to value stream mapping (VSM) analysis, the magnetization value of Cs–NiFe2O4 NPs (17.34 emu/g) was significantly lower than NiFe2O4 NPs (40.67 emu/g). The Cs–NiFe2O4 NPs indicated higher antibacterial properties than NiFe2O4 NPs and Cs. The minimum inhibitory concentrations of Cs–NiFe2O4 NPs against S. aureus and E. coli were 128 and 256 mg/mL, respectively. Antioxidant activity (evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging test) for NiFe2O4 NPs and Cs–NiFe2O4 NPs at the concentration of 100 µg/mL were 35% and 42%, respectively. Consequently, the synthesized Cs–NiFe2O4 NPs can be proposed as a viable material for biomedical applications.

Design and Development of Novel Composites Containing Nickel Ferrites Supported on Activated Carbon Derived from Agricultural Wastes and Its Application in Water Remediation

Recently, efficient decontamination of water and wastewater have attracted global attention due to the deficiency in the world's water sources. Herein, activated carbon (AC) derived from willow catkins (WCs) was successfully synthesized using chemical modification techniques and then loaded with different weight percentages of nickel ferrite nanocomposites (10, 25, 45, and 65 wt.%) via a one-step hydrothermal method. The morphology, chemical structure, and surface composition of the nickel ferrite supported on AC (NFAC) were analyzed by XRD, TEM, SEM, EDX, and FTIR spectroscopy. Textural properties (surface area) of the nanocomposites (NC) were investigated by using Brunauer-Emmett-Teller (BET) analysis. The prepared nanocomposites were tested on different dyes to form a system for water remediation and make this photocatalyst convenient to recycle. The photodegradation of rhodamine B dye was investigated by adjusting a variety of factors such as the amount of nickel in nanocomposites, the weight of photocatalyst, reaction time, and photocatalyst reusability. The 45NFAC photocatalyst exhibits excellent degradation efficiency toward rhodamine B dye, reaching 99.7% in 90 min under a simulated source of sunlight. To summarize, NFAC nanocomposites are potential photocatalysts for water environmental remediation because they are effective, reliable, and reusable.

Facile green synthesis of nickel-ferrite-rGO (NiFe2O4/rGO) nanocomposites for efficient water purification under direct sunlight

• Green synthesis of NiFe 2 O 4 /rGO nanocomposites using peppermint leaf extract ( Mentha piperita ). • Efficient photocatalytic degradation of cationic and anionic dyes. • Detailed kinetic study of the photocatalytic reactions. • High magnetic separation and recyclability of the synthesized nanocomposites. Facile green synthesis of magnetically separable nickel-ferrite nanocomposites supported over reduced graphene oxide (NiFe 2 O 4 /rGO) using peppermint leaf extract as reducing agent is reported herein. The as-synthesized nanocomposites are magnetic in nature and can be used as fine photocatalysts. It is fascinating that the mixing of inert NiFe 2 O 4 with GO nanosheet produces highly active photocatalyst after the reduction of GO to reduced graphene oxide (rGO). The nanocomposites have been well characterized using different analytical techniques. Morphological and structural studies have shown the formation of spherical NiFe 2 O 4 nanocomposites with particle size 3-5 nm, regularly supported over the layers of rGO. The nanocomposites have actively participated in the photocatalytic degradation of different dyes under direct sunlight within a very limited time. Congo red and Malachite green are completely degraded in 18 mins, while Methylene blue and Methyl orange are completely degraded in 30 and 12 mins respectively. Moreover, study showed that 30 mgL -1 nanocomposite was sufficient to degrade all the dyes completely. However, depending on the Ni/Fe ratio, the photocatalytic activity has been varied. Recovery and reusability of the nanocomposites have been done very smoothly because of the magnetically separable behavior of the nanocomposites, which shows the efficiency of the catalysts up-to 4 th cycle with very minimal loss in activity. This green strategy of the synthesis and utilization of magnetically separable NiFe 2 O 4 /rGO nanocomposites for the waste water purification is remarkable.

2-(Anthracen-9-yl)benzothiazole-modified graphene oxide-nickel ferrite nanocomposite for anodic stripping voltammetric detection of heavy metal ions.

A novel electrochemical sensor, 2-(anthracen-9-yl)benzothiazole (ABT)-modified nickel ferrite reduced graphene oxide (NF@rGO) has been designed for the individual and simultaneous detection of Cd2+, Cu2+, and Hg2+ ions. Herein, NF@rGO nanocomposite, synthesized by a simple hydrothermal methodology, was hooked to ABT under easy and simple stirring conditions. Chelation of active functional groups of ABT with metal ions was augmented with higher adsorption and conductivity provided by NF@rGO. The created synergy resulted in analytical signals via selective oxidation of the ions within a potential ranging from - 1.2 to + 1.2Vvs sat. KCl. The proposed protocol exhibited a wide linear range from 0.05 to 1250nM with excellent detection limit of 123, 54.1, and 86.6pM via anodic stripping voltammetry for the simultaneous determination of Cd2+, Cu2+, and Hg2+ ions, respectively. Simple cost-effective synthetic approach, improved sensitivity with high selectivity, noteworthy repeatability (RSD less than 3%), and reproducibility (RSD less than 7%) equipped with successful real time monitoring (apparent recovery more than 90%) bring about a spiffing sensing platform for the detection of hazardous metal ions.

Enhanced electromagnetic shielding effectiveness of MWCNT/zinc-doped nickel ferrite nanocomposites

Nano-composites of MWCNTs and Ni0.5Zn0.5Fe2O4 were synthesized by two different methods i.e. co-precipitation (CM) and physical-mixing (PM). Properties of synthesized materials were studied by various analytical equipments/techniques viz. X-ray diffraction (XRD), Raman spectroscopy, scanning and transmission electron microscopy (SEM and TEM), UV–visible spectroscopy and N5230C vector network analyzer (VNA). The XRD and Raman Spectroscopy confirmed the crystalline phase formation of NZF nano-particles and hybrid NZF/MWCNT nano-composites. The FESEM and TEM images revealed hexagonal flake-like structure of NZF deposited on MWCNTs. The energy band gap of NZF, PM and CM was obtained to be 1.9 eV, 1.3 eV and 1.1 eV respectively. The Electromagnetic interference performance of Ni0.5Zn0.5Fe2O4/MWCNTs nano-composite are reported in the manuscript. The dielectric parameters and EMI shielding effectiveness of nano-materials were carried out by Vector Network Analyzer in the X-band frequency region. The reflection loss (RL) was observed to be maximum with a value of −51.2 dB for PM sample at 11.2 GHz. Total shielding effectiveness of 40.1 dB was observed for CM nano-composite in X-band in frequency range 8.2 GHz–12.4 GHz and thus, these composite materials are good for wider applications in electromagnetic absorption devices.

Predictive capability evaluation and optimization of Pb(II) removal by reduced graphene oxide-based inverse spinel nickel ferrite nanocomposite

Pb(II) is a heavy metal that is a prominent contaminant in water contamination. Among the different pollution removal strategies, adsorption was determined to be the most effective. The adsorbent and its type determine the adsorption process's efficiency. As part of this effort, a magnetic reduced graphene oxide-based inverse spinel nickel ferrite (rGNF) nanocomposite for Pb(II) removal is synthesized, and the optimal values of the independent process variables (like initial concentration, pH, residence time, temperature, and adsorbent dosage) to achieve maximum removal efficiency are investigated using conventional response surface methodology (RSM) and artificial neural networks (ANN). The results indicate that the initial concentration, adsorbent dose, residence time, pH, and process temperature are set to 15 mg/L, 0.55 g/L, 100 min, 5, and 30 °C, respectively, the maximum removal efficiency (99.8%) can be obtained. Using the interactive effects of process variables findings, the adsorption surface mechanism was examined in relation to process factors. A data-driven quadratic equation is derived based on the ANOVA, and its predictions are compared with ANN predictions to evaluate the predictive capabilities of both approaches. The R2 values of RSM and ANN predictions are 0.979 and 0.991 respectively and confirm the superiority of the ANN approach.

Magnetic properties and kinetic roughening study of prepared polyaniline: lead ferrite, cobalt ferrite and nickel ferrite nanocomposites electrodeposited thin films

The purpose of this study is preparation of polyaniline–lead ferrite, polyaniline–cobalt ferrite and polyaniline/nickel ferrite thin layers. The electromagnetic pollution is a serious problem in the world that can be solved by electromagnetic interference (EMI) shielding. The EMI layers can be synthesized by conductive layer composed by magnetic particles. Crystallite size of samples was studied by (XRD) analyze via Debye–Scherrer and Williamson–Hall equations. The X-ray diffraction XRD patterns confirm the crystalline structure of the samples. The surface morphology of the composite layers was investigated by scanning electron microscopy (SEM) and the effect of thickness and different composed particles was investigated. The percentage of the constituents and purity of samples was studied by energy dispersive X-ray analysis (EDX) analysis. Also, surface roughness and kinetic roughening of thin films was investigated using atomic force microscopy (AFM). Hysteresis loop of the magnetic samples were analyzed by vibrating sample magnetometer (VSM). These new easy prepared nanocomposites introduce a suitable and effective coating for electromagnetic interference (EMI) shielding.

Modeling of phenol removal from water by NiFe2O4 nanocomposite using response surface methodology and artificial neural network techniques

This study demonstrates the synthesis, characterization, and modeling of nickel ferrite nanocomposite, NiFe2O4 (NFC) as an adsorbent for the phenol contaminated aqueous environment. The characterization of the prepared NFC was performed with X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) techniques. The optimization and modeling of phenol removal using NFC was done through central composite design (CCD) and effective parameters of CCD were measured as input variables including the amount of NFC, pH, contact time and initial phenol concentration. The predicted results showed that the adsorption process using NFC as adsorbent had the maximum phenol removal (~99%) under predicted optimal conditions (pH = 7.67, NFC dosage = 0.15 g at room temperature), which also corresponded to the experimental values. In addition, a multilayer feed-forward artificial neural network (ANN) model was used to obtain a speculative phenol removal model. The network was trained for six replications after selection of the best neuron number for hidden layer. The value of MSE trained network was found to be 6.01718e-3 along with regression coefficient (R2 = 0.9934) that indicated satisfactory relationship. Isothermal modeling of phenol adsorption onto NFC was performed using well-known Temkin, Freundlich and Langmuir models and it was clear from the higher R2 value of 0.961 that the Langmuir model was significantly followed by experimental data. The maximum Langmuir adsorption capacity was found to be 274.72 mg/g at the optimal conditions. The obtained results prove that NFC could be an effective adsorbent for elimination of phenol contaminant from aqueous environment.

Adsorption of pharmaceuticals pollutants, Ibuprofen, Acetaminophen, and Streptomycin from the aqueous phase using amine functionalized superparamagnetic silica nanocomposite

Pharmaceuticals are one of the emerging pollutants that pose a severe threat to the aquatic habitats, which in turn affects other species in the biosphere. The superparamagnetic based silica nanocomposites modified with aminosilane were characterized for their physicochemical properties and also the purity of the nanocomposite obtained was determined. The adsorptive properties of the nanocomposites were investigated for the removal of pharmaceutical pollutants such as Ibuprofen, Acetaminophen, and Streptomycin from aqueous solutions. The adsorption process of pharmaceuticals was found to reach equilibrium within the first 15 min reporting high removal efficiency of up to 97% for Ibuprofen (IBF) followed by (94%) acetaminophen (ACE) and (70%) streptomycin (STR) for a concentration of 12 mg L−1. The adsorption process was found to follow the pseudo-second-order kinetics and fits well with the Langmuir isotherm model, confirming the adsorption on to the homogenous surface of the nanocomposite. The amine functional groups formed on the nickel ferrite nanocomposites by coating aminopropyltrimethoxysilane (APTS) were observed to aid the adsorption process. The adsorption capacity of the nanocomposites varies for IBF, ACE, and STR as 59, 58, and 49 mg g−1 at pH 7.0, 6.0, and 5.0, respectively. The amine coated magnetic nanocomposite also showed excellent regeneration capacity for up to four cycles and can be a promising adsorbent, especially for removing of pharmaceutical pollutants from aqueous streams.

Absorption properties of CNF mixed cobalt nickel ferrite nanocomposite for radar and stealth applications

For the first time, the cobalt doped nickel ferrite/carbon nano-fiber based nanocomposites are synthesized for radar and stealth applications. Initially, the CoxNi1−xFe2O4 with x = 0.0–0.4, nanoparticles are synthesized and then dispersed in the epoxy matrix to investigate their microwave absorption properties. Among all the synthesized nanocomposites, the CoxNi1−xFe2O4, x = 0.4 (55 wt% epoxy) nanocomposite exhibits maximum −10 dB absorption bandwidth of 1.4 GHz only for 10.3 mm thick sample. The synthesized nanocomposite is not suitable to be used for aforementioned application due to high thickness and low absorption bandwidth. To overcome this problem, carbon nanofiber (CNF ~ 1, 2 and 3 wt% epoxy) is added to the earlier synthesized ferrite epoxy system. The nanocomposite sample consisting of CoxNi1−xFe2O4, x = 0.4 (55 wt% epoxy) and CNF (2 wt% epoxy) shows enhanced absorption bandwidth of 3.23 GHz at a very low thickness of 1.6 mm. The addition of CNF into the ferrite system thus substantially enhanced the microwave absorption properties of the resultant nanocomposite, suitable for the radar and stealth applications.

Synthesis of magnetic nickel ferrites nanocomposites: An advanced remediation of electroplating wastewater

Nickel ferrite nanocomposites (NFNCs) were prepared and utilized to remove hexavalent chromium from the effluent of the electroplating industry. The nickel ferrite nanoparticles (NFNPs) were synthesized by the sol-gel auto combustion process, and they were doped ultrasonically onto the surface-modified multi-walled carbon nanotubes (SM-MWCNTs). Characterization results confirmed that the NFNPs with a cubic spinel structure were successfully impregnated onto the SM-MWCNTs. The synthesized NFNCs were tubular structures with an outer diameter in the range of 30–40 nm and had high crystal defect. The NFNCs with the surface area of 210.5 m2 g−1 offer high magnetic separability due to their paramagnetic behavior. Non-linear kinetic, thermodynamic, and isotherm models were used for interpretations, and high Cr(VI) uptake of 129.83 mg/g was obtained at 40 °C. The Cr(VI) uptake by NFNCs was dominated by electrostatic attractions at a low pH and ion exchange mechanism at a higher pH. Lastly, high efficient recyclability of the NFNCs and applicability in removing other heavy metals from electroplating effluent suggested them to be a promising material in wastewater treatment.

The electrical properties of NiFe2O4-PVDF nanocomposite prepared by sol-gel method

NiFe2O4 nanocomposite is a soft magnetic material with low saturation coercivity and magnetization but has high electrical resistivity making this material suitable for electric field applications. The purpose of this study was to determine the effect of NiFe2O4 composition on the electrical properties of NiFe2O4-PVDF nanocomposites prepared by the sol-gel method. Nickel Ferrite nanocomposites - polyvinylidene fluoride (NiFe2O4-PVDF) are made using the sol-gel method and then grown using a spin coating device on a glass substrate. NiFe2O4-PVDF nanocomposites are characterized using X-ray diffraction (XRD) which aims to determine the crystal system, whereas to determine the electrical properties of nanocomposite resistivity Four Point Probe are used. Based on the research conducted on the electrical properties of the NiFe2O4-PVDF nanocomposite, the resistivity value of the NiFe2O4- PVDF nanocomposite with variations in the composition of the PVDF used 10:10, 10:20, and 10:30 was 36.66913333 Ohm.m; 55,63242667 Ohm.m; and 20,85797333 (Ohm.m). While the results of the resistivity values of the nanocomposite NiFe2O4-PVDF with variations in the composition of NiFe2O4 used 10:10, 20:10, and 30:10 are 36,69613333 Ohm.m; 12.07853333 Ohm.m; and 9.616773333 (Ohm.m). It can be concluded that the greater the variation in the composition of NiFe2O4 and PVDF, the resistivity value decreases.

Cd2+ substituted nickel ferrite doped polyaniline nanocomposites as effective shield against electromagnetic radiation in X-band frequency

Abstract Polyaniline encapsulated Cd 2+ substituted nickel ferrite nanocomposites with different weight ratio (polyaniline/NiCd ferrite = 15, 25 and 30%) have been synthesized via in situ polymerization. The XRD (X-ray diffraction), FT-IR (Fourier transform infrared spectroscopy), UV–Vis spectra and TEM (Transmission electron microscopy) analysis confirmed the successful formation of conducting–ferromagnetic polymer nanocomposites. Electrical properties (DC) of the samples were measured by the FPR (Four probe resistivity) technique. TGA (Thermo-gravimetric analysis) analysis indicated improved thermal stability of composites with rising ferrite content in the polymer matrix. These nanocomposites exhibit ferromagnetism at room temperature with the increased saturation magnetization from 13.92 to 23.49 emu/g as revealed by VSM (Vibrating sample magnetometer) results. From VNA (Vector network analyzer) study, it was found that the composite containing 30 wt% NiCdFe 2 O 4 showed the maximum SE T (42.7 dB) in X-band range due to the synergistic tuning of magnetic and conductive nanoparticles, presenting them as an effective EMI shield for various electrical, electronic and radiation equipments.

Modified nickel ferrite nanocomposite/functionalized chitosan as a novel adsorbent for the removal of acidic dyes

As a new type of magnetic adsorbent, a nickel ferrite nanocomposite modified by functionalized chitosan was developed to remove methyl orange and Congo red from aqueous solutions. This new adsorbent was characterized and utilizing batch adsorption approach, the mechanism of methyl orange and Congo red removal were probed. Following that the study on pertinent parameters which could influence the efficiency of the dyes removal, i.e. pH of the solution, initial dye concentration, dose of the adsorbent, and contact time were accomplished in order to arrive their optimized values by using response surface methodology. In addition, kinetics and isotherm studies were conducted on the developed system. Langmuir model was used to probe adsorption isotherm, acquiring adsorption capacity of 551.2 and 274.7 mg g−1 for methyl orange and Congo red, respectively. Both of methyl orange and Congo red adsorption kinetics obeyed a pseudo-second-order kinetic model, indicating that adsorption was the rate-limiting step and only 5 min was required to remove 50% of dyes. The fitting of experimental data was fulfilled with intra-particle diffusion reaching to conclusion that the adsorption kinetic could be controlled simultaneously by film diffusion and intra-particle diffusion. Furthermore, the desorption studies of dyes showed that the adsorbent is reusable.

Magnetic Graphene Oxide Composites are the Solutions for Sustainable Remediation of Ecosystems

Heavy metals are one of the primary contaminants in the environment [1]. Exposure to heavy metals, even at trace levels, is believed to be a high health risk for humans [2,3]. Heavy metals are naturally occurring throughout the earth’s crust [4]. But most of the environmental contamination results from the anthropogenic activities such as mining and smelting operations, industry, and domestic and agricultural use of metals and metalcontaining compounds. Migration of these contaminants into non-contaminated areas as dust or leachates through the soil and spreading of heavy metals containing sewage sludge are a few examples of events contributing towards contamination of the ecosystems [5]. Hence, water is the one of the major routes through which heavy metals and radionuclides may enter the human body [6,7]. The sources of water pollution are shown in Figure 1. The conventional wastewater purification techniques including chemical coagulation, photo degradation, precipitation, flocculation, activated sludge, membrane separation and ion exchange are limited to the removal of heavy metals at trace levels [7-9]. However, adsorption is one of the best methods for the purification of water, owing to its low cost and easy handling of materials [7,10-12]. Moreover, adsorption approaches using commercial activated carbon, micro-filtration and membrane techniques are effective, but their use is limited by the complicated installation process involved coupled with the high maintenance costs of the systems [7,13]. Hence, these drawbacks have necessitated the search for an alternative method which is inexpensive, renewable and cost-effective for the removal of heavy metals from aqueous solutions. Many scientific groups have prepared graphene or graphene oxide (GO) based hybrid nanocomposites for various potential applications [14-17]. The study of literature survey and stability of the GO-based nanocomposites prompted us to survey on graphene oxide and reduced graphene oxide-based inverse spinel nickel ferrite nanocomposites for the removal of heavy metals and radionuclides from water with the purpose of reducing their environmental impact

Preparation and characterization of porous reduced graphene oxide based inverse spinel nickel ferrite nanocomposite for adsorption removal of radionuclides

For the removal of uranium(VI) (U(VI)) and thorium(IV) (Th(IV)), graphene oxide based inverse spinel nickel ferrite (GONF) nanocomposite and reduced graphene oxide based inverse spinel nickel ferrite (rGONF) nanocomposite were prepared by co-precipitation of GO with nickel and iron salts in one pot. The spectral characterization analyses revealed that GONF and rGONF have a porous surface morphology with an average particle size of 41.41nm and 32.16nm, respectively. The magnetic property measurement system (MPMS) studies confirmed the formation of ferromagnetic GONF and superparamagnetic rGONF. The adsorption kinetics studies found that the pseudo-second-order kinetics was well tune to the U(VI) and Th(IV) adsorption. The results of adsorption isotherms showed that the adsorption of U(VI) and Th(IV) were due to the monolayer on homogeneous surface of the GONF and rGONF. The adsorptions of both U(VI) and Th(IV) were increased with increasing system temperature from 293 to 333±2K. The thermodynamic studies reveal that the U(VI) and Th(IV) adsorption onto GONF and rGONF was endothermic. GONF and rGONF, which could be separated by external magnetic field, were recycled and re-used for up to five cycles without any significant loss of adsorption capacity.

Porous graphene oxide based inverse spinel nickel ferrite nanocomposites for the enhanced adsorption removal of arsenic

Porous nanocomposites, graphene oxide based-inverse spinel nickel ferrite (GONF) and reduced graphene oxide based-inverse spinel nickel ferrite (rGONF), were prepared by co-precipitation of graphene oxide (GO) with nickel and iron salts at one pot.