Surface adsorption of poisonous Pb(II) ions from water using chitosan functionalised magnetic nanoparticles

In this study, chitosan functionalised magnetic nano‐particles (CMNP) was synthesised and utilised as an effective adsorbent for the removal of Pb(II) ions from aqueous solution. The experimental studies reveal that adsorbent material has finer adsorption capacity for the removal of heavy metal ions. Parameters affecting the adsorption of Pb(II) ions on CMNP, such as initial Pb(II) ion concentration, contact time, solution pH, adsorbent dosage and temperature were studied. The adsorption equilibrium study showed that present adsorption system followed a Freundlich isotherm model. The experimental kinetic studies on the adsorption of Pb(II) ions exhibited that present adsorption process best obeyed with pseudo‐first order kinetics. The maximum monolayer adsorption capacity of CMNP for the removal of Pb(II) ions was found to be 498.6 mg g⁻¹. The characterisation of present adsorbent material was done by FTIR, energy disperse X‐ray analysis and vibrating sample magnetometer studies. Thermodynamic parameters such as Gibbs free energy (ΔG °), enthalpy (ΔH °) and entropy (ΔS °) have declared that the adsorption process was feasible, exothermic and spontaneous in nature. Sticking probability reported that adsorption of Pb(II) ions on CMNP was favourable at lower temperature and sticking capacity of Pb(II) ions was very high.Inspec keywords: adsorption, lead, wastewater treatment, monolayers, Fourier transform infrared spectra, X‐ray chemical analysis, magnetometers, pHOther keywords: poisonous Pb(II) ions surface adsorption, chitosan functionalised magnetic nanoparticle, CMNP, Pb(II) ions removal, aqueous solution, finer adsorption capacity, heavy metal ion removal, contact time, solution pH, adsorbent dosage, adsorption equilibrium, Freundlich isotherm model, pseudofirst order kinetics, monolayer adsorption capacity, FTIR, energy disperse X‐ray analysis, vibrating sample magnetometer study, thermodynamic parameter, sticking probability, Pb(II) ions sticking capacity, initial Pb(II) ion concentration     

Functional group‐assisted green synthesised superparamagnetic nanoparticles for the rapid removal of hexavalent chromium from aqueous solution

Superparamagnetic nanoparticles (NPs) prepared using the capping agent derived from the Lantana camara fruit extract were used to study the adsorption of chromium ions. Characterisation techniques such as scanning electron microscope, energy‐dispersive X‐ray, Fourier transform infrared spectroscopy, X‐ray diffraction, vibrating sample magnetometer and thermo gravimetric analysis (TGA) were used to study the NP features and adsorption mechanisms. The maximum monolayer adsorption capacity calculated from the Langmuir isotherm was found to be 41 mg/g. The chemical nature of the adsorption is confirmed with the results of Dubinin–Radushkevich model and thermodynamic studies. In addition, thermodynamically favourable and spontaneous adsorption is considered to be a good indication for the removal of metal ions. Out of the kinetic models investigated, the experiments exhibited the best fit to pseudo‐second‐order model, advocating for surface‐based adsorption, involving both physical and chemical interactions. It is also significant to note that 85% of the adsorption occurs in the first 10 min, and hence the selected adsorbent is also claimed for rapid removal of metal ions. The newly synthesised adsorbent hence possesses remarkable properties in terms of simple synthesising technique, low cost, rapid uptake and improved efficiency without generating harmful byproducts.Inspec keywords: superparamagnetism, nanoparticles, magnetic particles, nanofabrication, nanomagnetics, adsorption, chromium, Fourier transform infrared spectra, X‐ray diffraction, X‐ray chemical analysis, magnetometry, thermodynamic propertiesOther keywords: functional group‐assisted green synthesis, superparamagnetic nanoparticles, hexavalent chromium ions, aqueous solution, Fourier transform infrared spectroscopy, scanning electron microscopy, energy‐dispersive X‐ray spectra, X‐ray diffraction, vibrating sample magnetometry, TGA, Dubinin‐Radushkevich model, thermodynamic model, Langmuir isotherm, monolayer adsorption capacity, surface‐based adsorption, pseudosecond‐order adsorption model, chemical interactions, physical interactions, Cr     

Higher adsorption capacity of Spirulina platensis alga for Cr(VI) ions removal: parameter optimisation,equilibrium, kinetic and thermodynamic predictions

This study discusses about the biosorption of Cr(VI) ion from aqueous solution using ultrasonic assisted Spirulina platensis (UASP). The prepared UASP biosorbent was characterised by Fourier transform infrared spectroscopy, X‐ray diffraction, Brunauer–Emmet–Teller, scanning electron spectroscopy and energy dispersive X‐ray and thermogravimetric analyses. The optimum condition for the maximum removal of Cr(VI) ions for an initial concentration of 50 mg/l by UASP was measured as: adsorbent dose of 1 g/l, pH of 3.0, contact time of 30 min and temperature of 303 K. Adsorption isotherm, kinetics and thermodynamic parameters were calculated. Freundlich model provided the best results for the removal of Cr(VI) ions by UASP. The adsorption kinetics of Cr(VI) ions onto UASP showed that the pseudo‐first‐order model was well in line with the experimental data. In the thermodynamic study, the parameters like Gibb''s free energy, enthalpy and entropy changes were evaluated. This result explains that the adsorption of Cr(VI) ions onto the UASP was exothermic and spontaneous in nature. Desorption of the biosorbent was done using different desorbing agents in which NaOH gave the best result. The prepared material showed higher affinity for the removal of Cr(VI) ions and this may be an alternative material to the existing commercial adsorbents.Inspec keywords: adsorption, ultrasonic applications, Fourier transform infrared spectra, X‐ray diffraction, scanning electron microscopy, X‐ray chemical analysis, thermal analysis, chromium, free energy, enthalpy, entropy, desorption, water treatment, water pollution, biological techniques, microorganismsOther keywords: Cr⁴⁺ , entropy changes, enthalpy changes, Gibb''s free energy, pseudofirst‐order model, Freundlich model, thermogravimetric analyses, energy dispersive X‐ray, scanning electron spectroscopy, Brunauer‐Emmet‐Teller, X‐ray diffraction, Fourier transform infrared spectroscopy, UASP biosorbent, ultrasonic assisted Spirulina platensis, aqueous solution, chromium ion biosorption, thermodynamic prediction, kinetic prediction, equilibrium prediction, parameter optimisation, chromium ion removal, Spirulina platensis alga, adsorption capacity     

Biogenic synthesis of Au,Ag and Au–Ag alloy nanoparticles using Cannabis sativa leaf extract

Biogenic synthesis of gold (Au), silver (Ag) and bimetallic alloy Au–Ag nanoparticles (NPs) from aqueous solutions using Cannabis sativa as reducing and stabilising agent has been presented in this report. Formation of NPs was monitored using UV–visible spectroscopy. Morphology of the synthesised metallic and bimetallic NPs was investigated using X‐ray diffraction and scanning electron microscopy. Elemental composition and the surface chemical state of NPs were confirmed by energy dispersive X‐ray spectroscopy analysis. Fourier transform‐infrared spectroscopy was utilised to identify the possible biomolecules responsible for the reduction and stabilisation of the NPs. Biological applicability of biosynthesised NPs was tested against five bacterial strains namely Klebsiella pneumonia, Bacillus subtilis (B. subtilis), Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa (P. aeruginosa) and Leishmania major promastigotes. The results showed considerable antibacterial and anti‐leishmanial activity. The Au–Ag bimetallic NPs showed improved antibacterial activity against B. subtilis and P. aeruginosa as compared to Au and Ag alone, while maximum anti‐leishmanial activity was observed at 250 μg ml⁻¹ NP concentration. These results suggest that biosynthesised NPs can be used as potent antibiotic and anti‐leishmanial agents.Inspec keywords: silver, silver alloys, gold, gold alloys, nanoparticles, nanofabrication, reduction (chemical), ultraviolet spectra, visible spectra, X‐ray diffraction, scanning electron microscopy, X‐ray chemical analysis, Fourier transform infrared spectra, microorganisms, antibacterial activityOther keywords: biogenic synthesis, Cannabis sativa leaf extract, bimetallic alloy Au–Ag nanoparticles, aqueous solutions, reducing agent, stabilising agent, UV–visible spectroscopy, X‐ray diffraction, scanning electron microscopy, elemental composition, surface chemical state, energy dispersive X‐ray spectroscopy analysis, Fourier transform‐infrared spectroscopy, biomolecules, bacterial strains, Klebsiella pneumonia, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Leishmania major promastigotes, antibacterial activity, anti‐leishmanial activity, Ag, Au, AuAg     

Recyclable adsorbents based on Fe3 O4 nanoparticles on lanthanum‐modified montmorillonite for the efficient phosphate removal

Montmorillonite (MMT) clay modified with lanthanum (La) ions and Fe₃ O₄ nanoparticles was proposed for the effective removal of phosphate ions from aqueous solution. Characterisation of the adsorbent using FTIR, SEM, XRD, XPS, XRF, BET and VSM techniques were carried out. The effects of initial phosphate concentration, contact time, dosage and pH on the phosphorus adsorption were investigated. La‐MMT/Fe₃ O₄ exhibited an excellent adsorption capacity of up to 14.35 mg/g, with 97.8% removal within 60 min. Langmuir isotherm model fits well with the equilibrium isotherm data, with a maximum adsorption capacity of 15.53 mg/g at room temperature. The kinetic study was well fitted with pseudo‐second‐order kinetics, and the adsorption rate was mainly controlled by liquid‐film diffusion. The manufactured adsorbent was effectively regenerated using 0.1 M NaOH solutions, with 90.18% adsorption efficiency remaining after six adsorption/desorption cycles. These results demonstrate that La‐MMT/Fe₃ O₄ provides an example of regenerable high‐performance adsorbents for removal of PO₄ ³⁻ from wastewater.Inspec keywords: wastewater treatment, desorption, phosphorus, pH, recycling, adsorption, X‐ray diffraction, iron compounds, nanoparticles, X‐ray photoelectron spectra, clay, scanning electron microscopy, reaction kinetics theory, X‐ray fluorescence analysis, chemical engineering, chemical equilibrium, Fourier transform infrared spectra, sodium compounds, lanthanum, liquid films, diffusionOther keywords: maximum adsorption capacity, high‐performance adsorbents, recyclable adsorbents, lanthanum‐modified montmorillonite, montmorillonite clay, Langmuir isotherm model, phosphate removal, aqueous solution, FTIR spectroscopy, SEM, XRD, XPS, XRF, BET, VSM techniques, pH value, equilibrium isotherm data, pseudo second‐order kinetics, liquid‐film diffusion, adsorbent regeneration, adsorption‐desorption cycles, wastewater treatment, temperature 293.0 K to 298.0 K, time 60.0 min, NaOH, La, P     

Nano‐zero valent iron impregnated cashew nut shell: a solution to heavy metal contaminated water/wastewater

The present research is focused on the removal of Zn(II) ions from aqueous solution using nano zero‐valent iron impregnated cashew nut shell (NZVI‐CNS). The present system was investigated in batch mode operation. NZVI‐CNS was prepared by the liquid‐phase reduction process. The results showed that the NZVI‐CNS exhibited superior adsorption capacity for the removal of Zn(II) ions. Adsorption isotherm and kinetic models were applied to explain the nature of the adsorption process. Adsorption kinetic data followed the pseudo‐first order kinetic model. Moreover, the equilibrium adsorption data were best fitted with a Freundlich model. Langmuir monolayer adsorption capacity was calculated as 94.46 mg of Zn(II) ions/g of NZVI‐CNS. The thermodynamic parameters explain that the present adsorption system was measured as feasible and spontaneous. This newly prepared adsorbent can be successfully applied for the different industrial wastewater treatment. Finally, the exploration asks about contemplated that NZVI‐CNS has exhibited unrivalled adsorption limit. Additionally, NZVI‐CNS is believed to be extremely green and monetarily neighbourly help for wastewater treatment. The results indicate that the feasible approach could be applied in agricultural waste biomass materials for the productive expulsion of heavy metals from aqueous solution and reusing agricultural wastes to facilitate their disposal problem.Inspec keywords: wastewater treatment, contamination, zinc, reduction (chemical), adsorption, monolayers, renewable materialsOther keywords: nano zero‐valent iron impregnated cashew nut shell, aqueous solution, Zn(II) ion removal, NZVI‐CNS, batch mode operation, liquid‐phase reduction process, adsorption capacity, adsorption isotherm models, adsorption kinetic models, adsorption kinetic data, adsorption process, pseudo‐first order kinetic model, equilibrium adsorption data, Freundlich model, Langmuir monolayer adsorption capacity, thermodynamic parameters, adsorption system, industrial wastewater treatment, agricultural waste biomass materials, productive expulsion, heavy metals, waste disposal, Zn     

Fabrication and characterisation of super‐paramagnetic responsive PLGA–gelatine–magnetite scaffolds with the unidirectional porous structure: a physicochemical,mechanical, and in vitro evaluation

Architecture and composition of Scaffolds are influential factors in the regeneration of defects. Herein, synthesised iron oxide (magnetite) nanoparticles (MNPs) by co‐precipitation technique were evenly distributed in polylactic‐co‐glycolic acid (PLGA)–gelatine Scaffolds. Hybrid structures were fabricated by freeze‐casting method to the creation of a matrix with tunable pores. The synthesised MNPs were characterised by transmission electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction spectroscopy, and vibrating sample magnetometer analysis. Scanning electron microscopy micrographs of porous Scaffolds confirmed the formation of unidirectional microstructure, so that pore size measurement indicated the orientation of pores in the direction of solvent solidification. The addition of MNPs to the PLGA–gelatine Scaffolds had no particular effect on the morphology of the pores, but reduced slightly pore size distribution. The MNPs contained constructs demonstrated increased mechanical strength, but a reduced absorption capacity and biodegradation ratio. Stability of the MNPs and lack of iron release was the point of strength in this investigation and were determined by atomic absorption spectroscopy. The evolution of rat bone marrow mesenchymal stem cells performance on the hybrid structure under a static magnetic field indicated the potential of super‐paramagnetic constructs for further pre‐clinical and clinical studies in the field of neural regeneration.Inspec keywords: transmission electron microscopy, biodegradable materials, nanofabrication, freezing, mechanical strength, tissue engineering, X‐ray diffraction, cellular biophysics, precipitation (physical chemistry), biomedical materials, iron compounds, porosity, scanning electron microscopy, atomic absorption spectroscopy, gelatin, nanoparticles, porous materials, bone, nanocomposites, Fourier transform infrared spectraOther keywords: unidirectional microstructure, pore size measurement, mechanical strength, atomic absorption spectroscopy, hybrid structure, super‐paramagnetic responsive PLGA–gelatine–magnetite scaffolds, unidirectional porous structure, tissue engineering Scaffolds, co‐precipitation technique, polylactic‐co‐glycolic acid–gelatine Scaffolds, freeze‐casting method, transmission electron microscopy, Fourier‐transform infrared spectroscopy, X‐ray diffraction spectroscopy, scanning electron microscopy micrographs, pore size distribution, absorption capacity, iron oxide nanoparticles, Fe₃ O₄      

Synthesis of Co3 O4 /graphene nanocomposite using paraffin wax for adsorption of methyl violet in water

This study discusses the use of Co₃ O₄ impregnated graphene (CoOIG) as an efficient adsorbent for the removal of methyl violet (MV) dye from wastewater. CoOIG nanocomposites have been prepared by pyrolyzing paraffin wax with cobalt acetate. The synthesised nanocomposite was characterised by X‐ray diffraction, field emission scanning electron microscope, transmission electron microscope, Fourier transform infrared spectroscope, Raman spectroscopy, and Brunauer–Emmett–Teller isotherm studies. The above studies indicate that the composites have cobalt oxide nanoparticles of size 51–58 nm embedded in the graphene nanoparticles. The adsorption studies were conducted with various parameters, pH, temperature and initial dye concentration, adsorbent dosage and contact time by the batch method. The adsorption of MV dye by the adsorbent CoOIG was about 90% initially at 15 min and 98% dye removal at pH 5. The data were fitted in Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich and Sips isotherm models. Various thermodynamic parameters like Gibbs free energy, enthalpy, and entropy of the on‐going adsorption process have also been calculated.Inspec keywords: cobalt compounds, graphene, nanoparticles, nanocomposites, nanofabrication, adsorption, dyes, scanning electron microscopy, field emission electron microscopy, transmission electron microscopy, Raman spectra, Fourier transform infrared spectra, free energy, enthalpy, entropyOther keywords: nanocomposite, paraffin wax, adsorption, methyl violet dye, water, X‐ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, Brunauer‐Emmett‐Teller isotherm, cobalt oxide nanoparticles, graphene nanoparticles, thermodynamic parameters, Gibbs free energy, enthalpy, entropy, Co₃ O₄ ‐C     

Sorption of Cu(II) ions by nano‐scale zero valent iron supported on rubber seed shell

This study focused on synthesising nano‐scale zero valent iron (NZVI) impregnated on a low‐cost agro‐waste material, rubber seed shell (RSS), by borohydride reduction method. The characterisation studies of NZVI‐RSS were performed by Fourier transform infrared spectroscopy, scanning electron microscopy and X‐ray diffraction. The adsorption execution of NZVI‐RSS for Cu(II) ions evacuation from synthetic wastewater was explored by batch studies. The optimum condition for the present adsorption system is as follows: Cu(II) ion concentration = 25 mg/l; solution pH = 6.0; contact time = 30 min; NZVI‐RSS dose = 3 g/l; temperature = 30°C. The sorption data were best portrayed by pseudo‐first‐order and Freundlich models. The outcomes demonstrated the multilayer sorption of Cu(II) ions by NZVI‐RSS. The Langmuir capacity was observed as 48.18 mg/g. Thermodynamic parameters, ΔG °, ΔH ° and ΔS ° were ascertained, and it was watched that the adsorption system was unconstrained and exothermic. The sticking probability for Cu(II) ions by NZVI‐RSS was found to be high at lower temperature. At long last, the research inquire about reasoned that NZVI‐RSS has demonstrated unrivalled adsorption capacity. Also NZVI‐RSS is thought to be really green and financially amicable support for wastewater treatment.Inspec keywords: adsorption, copper, X‐ray diffraction, scanning electron microscopy, wastewater treatment, Fourier transform infrared spectroscopyOther keywords: nano‐scale zero valent iron, rubber seed shell, copper ions, borohydride reduction method, NZVI‐RSS, Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction, adsorption execution, synthetic wastewater, Langmuir capacity, Freundlich models, adsorption system, wastewater treatment, adsorption capacity, Cu     

Synthesis and application of alginate immobilised banana peels nanocomposite in rare earth and radioactive minerals removal from mine water

This study describes the preparation, characterisation and application of pelletised immobilised alginate/montmorillonite/banana peels nanocomposite (BPNC) in a fixed‐bed column for continuous adsorption of rare earth elements and radioactive minerals from water. The materials was characterised by Fourier transform infrared, X‐ray diffraction and scanning electron microscopy analyses. Analyses indicated that the pellets are porous and spherical in shape. FT‐IR analysis showed that the functional groups responsible for the coordination of metal ions were the carboxylic (–COO–) and siloxane (Si–O–Si and Si–O–Al) groups. XRD analysis showed two additional peaks which were attributed to alginate and montmorillonite. The influence of the initial concentration, bed depth and flow rate were investigated using synthetic and real mine water in order to determine the breakthrough behaviour of both minerals. The processed bed volume, adsorbent exhaustion rate and service time, were also explored as performance indices for the adsorbent material. Furthermore, the breakthrough data were fitted to both the Thomas and Bohart–Adams models. The BPNC exhibited high affinity for U, Th, Gd and La in the real mine water sample. However, studies may still be required using waters from different environments in order to determine the robustness of BPNC.Inspec keywords: scanning electron microscopy, nanocomposites, chemical technology, X‐ray diffraction, minerals, adsorption, wastewater treatment, Fourier transform infrared spectra, hazardous materials, nanofabrication, waste recovery, recycling, uranium, thorium, gadolinium, lanthanumOther keywords: fixed‐bed column, rare earth elements, adsorption process, microstructural analysis, bed depth, flow rate, processed bed volume, adsorbent exhaustion rate, mine water sample, X‐ray diffraction analysis, scanning electron microscopy analyses, siloxane group, pelletised immobilised alginate‐montmorillonite‐banana peels nanocomposite, radioactive mineral removal, Fourier transform infrared spectroscopy, carboxylic group, Thomas model, Bohart–Adams model, U, Th, Gd, La     

Biosynthesis and characterisation of nano‐silica as potential system for carrying streptomycin at nano‐scale drug delivery

A growing trend within nanomedicine has been the fabrication of self‐delivering supramolecular nanomedicines containing a high and fixed drug content ensuring eco‐friendly conditions. This study reports on green synthesis of silica nanoparticles (Si‐NPs) using Azadirachta indica leaves extract as an effective chelating agent. X‐ray diffraction analysis and Fourier transform‐infra‐red spectroscopic examination were studied. Scanning electron microscopy analysis revealed that the average size of particles formed via plant extract as reducing agent without any surfactant is in the range of 100–170 nm while addition of cetyltrimethyl ammonium bromide were more uniform with 200 nm in size. Streptomycin as model drug was successfully loaded to green synthesised Si‐NPs, sustain release of the drug from this conjugate unit were examined. Prolong release pattern of the adsorbed drug ensure that Si‐NPs have great potential in nano‐drug delivery keeping the environment preferably biocompatible, future cytotoxic studies in this connection is helpful in achieving safe mode for nano‐drug delivery.Inspec keywords: silicon compounds, nanofabrication, nanomedicine, drug delivery systems, nanoparticles, X‐ray diffraction, Fourier transform infrared spectra, scanning electron microscopyOther keywords: nanosilica, streptomycin, nanoscale drug delivery, nanomedicine, silica nanoparticles, Azadirachta indica leaves extract, X‐ray diffraction analysis, Fourier transform‐infrared spectroscopy, scanning electron microscopy, cetyltrimethyl ammonium bromide, SiO₂      

Fabrication of superparamagnetic adsorbent based on layered double hydroxide as effective nanoadsorbent for removal of Sb (III) from water samples

In this study, the superparamagnetic adsorbent as Fe@Mg‐Al LDH was synthesised by different methods with two steps for the removal of heavy metal ions from water samples. An easy, practical, economical, and replicable method was introduced to remove water contaminants, including heavy ions from aquatic environments. Moreover, the structure of superparamagnetic adsorbent was investigated by various methods including Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and vibrating sample magnetometer. For better separation, ethylenediaminetetraacetic acid ligand was used, forming a complex with antimony ions to create suitable conditions for the removal of these ions. Cadmium and antimony ions were studied by floatation in aqueous environments with this superparamagnetic adsorbent owing to effective factors such as pH, amount of superparamagnetic adsorbent, contact time, sample temperature, volume, and ligand concentration. The model of Freundlich, Langmuir, and Temkin isotherms was studied to qualitatively evaluate the adsorption of antimony ions by the superparamagnetic adsorbent. The value of loaded antimony metal ions with Fe@Mg‐Al LDH was resulted at 160.15 mg/g. The standard deviation value in this procedure was found at 7.92%. The desorption volume of antimony metal ions by the adsorbent was found to be 25 ml. The thermodynamic parameters as well as the effect of interfering ions were investigated by graphite furnace atomic absorption spectrometry.     

Phyto‐mediated synthesis,biological and catalytic activity studies of gold nanoparticles

In the present study, a phyto‐mediated synthesis of gold nanoparticles (AuNPs) using an isoflavone, Dalspinosin (5,7‐dihydroxy‐6,3′,4′‐trimethoxy isoflavone) isolated from the alcoholic extract of roots of Dalbergia coromandeliana is reported. It is observed that Dalspinosin itself acts both as a reducing and a capping agent in the synthesis of the nanoparticles (NPs). An ultraviolet–visible (UV–Vis) spectral study showed a surface plasmon resonance band at 526 nm confirming the formation of AuNPs. The NPs formed were characterised by UV–Vis spectroscopy, Fourier transform‐infrared spectroscopy, X‐ray diffraction (XRD), high‐resolution transmission electron microscopy (HR‐TEM) with energy‐dispersive x‐ray spectroscopy (EDX) and dynamic light scattering. HR‐TEM analysis showed the synthesised AuNPs were spherical in shape with a size of 7.5 nm. The AuNPs were found to be stable for seven months when tested by in vitro methods showed good antioxidant and anti‐inflammatory activities. They also showed moderate anti‐microbial activities when tested against Gram positive (Staphylococcus aureus and Streptococcus sp), Gram negative bacterial strains (Klebsiella pneumonia and Klebsiella terrigena) and fungal strain (Candida glabrata). The biosynthesised AuNPs showed significant catalytic activity in the reduction of methylene blue with NaBH₄ to leucomethylene blue.Inspec keywords: biomedical materials, catalysis, Fourier transform infrared spectra, gold, light scattering, microorganisms, nanomedicine, nanoparticles, spectrochemical analysis, surface plasmon resonance, transmission electron microscopy, ultraviolet spectra, visible spectra, X‐ray chemical analysis, X‐ray diffractionOther keywords: phyto‐mediated synthesis, biological activity studies, catalytic activity studies, dalspinosin (5,7‐dihydroxy‐6,3′,4′‐trimethoxy isoflavone), alcoholic extract, roots, Dalbergia coromandeliana, ultraviolet‐visible spectral study, surface plasmon resonance band, UV‐Vis spectroscopy, Fourier transform‐infrared spectroscopy, X‐ray diffraction, high‐resolution transmission electron microscopy, EDX analysis, dynamic light scattering, HR‐TEM analysis, antioxidant activities, antiinflammatory activities, antimicrobial activities, Gram positive bacterial strains, Staphylococcus aureus, Streptococcus sp, Gram negative bacterial strains, wavelength 526 nm, size 7.5 nm, time 7 month, Au     

Facile synthesis and application of cellulosic coagulant from banana peels in cadmium‐spiked water

Cellulosic coagulant with low crystallinity and surface charge of −19.2 mV were extracted from wet banana peels (WBE) using kitchen‐blending method. Functionalization with ferric chloride and aluminium chloride yielded higher surface charge of −23.8 mV (mWBE). Both WBE and mWBE coagulants were used to target cadmium ions from aqueous solution. Coagulants and the floccules (WBEA and mWBEA) were characterized by XRD, FT‐IR, zeta sizer nano series, and SEM/EDs. The amount of cadmium ion coagulated was determined using ICP‐OES. The FTIR analysis revealed the functional groups involved in the coordination and subsequent removal of the metals ions around 1634 cm⁻¹, ascribed to the C = O vibrational band of carbonyl group. Microscopic analysis revealed that the mWBE is porous and exhibited microfibers with rod‐like morphology. The effects of parameters such as the initial concentration, coagulant dosage and solution pH were investigated. Coagulation results showed that 10 mg of WBE and mWBE could remove about 80% and 90% of the Cd²⁺ ions respectively. However; the difference in the performance of both materials does not justify the essence of surface modification. Therefore, WBE is considered more efficient and environmentally friendly. Notwithstanding, the performance of these coagulants in real environmental samples will confirm their robustness.Inspec keywords: electrokinetic effects, nanofabrication, porosity, cadmium, toxicology, pH, scanning electron microscopy, X‐ray diffraction, coagulation, wastewater treatment, Fourier transform infrared spectra, industrial waste, waste reduction, waste recovery, recycling, separation, iron compounds, aluminium, blending, hazardous materialsOther keywords: cadmium‐spiked water, low crystallinity, modified WBE, scanning electron microscopy, aqueous solution, inductively coupled plasma optical emission spectroscopy, cellulosic coagulant synthesis, kitchen‐blending method, high surface charge, unmodified wet banana peel extract, X‐ray diffraction, Fourier transform infrared spectroscopy, zeta‐sizer nano series, solution pH, metal ions removal, microstructural analysis, chemical interaction, surface modification, coagulant microfibres, porosity, mass 10.0 mg, Cd, FeCl₃ , AlCl₃      

Biosynthesis of γ ‐Fe2 O3 @CuO core–shell nanoclusters using aqueous extract of Sesbania grandiflora Linn fresh leaves,its characterisation,and antimicrobial activity studies against Staphylococcus aureus strains

The present study reports an eco‐friendly and rapid method for the synthesis of core–shell nanoclusters using the modified reverse micelle method. It is a green synthetic method which uses Sesbania grandiflora Linn extract which acts as a reducing and capping agent. It is observed that this method is very fast and convenient and the nanoclusters are formed with 5–10 min of the reaction time without using harsh conditions. The core–shell nanoclusters so prepared were characterised using UV–Vis spectroscopy, scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy. Further, their effective antibacterial activity towards the gram‐positive bacteria Staphylococcus aureus was found to be due to their smaller particle size.Inspec keywords: iron compounds, copper compounds, nanoparticles, particle size, nanofabrication, nanomedicine, biomedical materials, core‐shell nanostructures, antibacterial activity, ultraviolet spectra, visible spectra, microorganisms, reduction (chemical), scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectraOther keywords: biosynthesis, γ‐Fe₂ O₃ ‐CuO core‐shell nanoclusters, aqueous extract, Sesbania grandiflora Linn fresh leaves, antimicrobial activity, Staphylococcus aureus strains, eco‐friendly method, modified reverse micelle method, green synthetic method, reducing agent, capping agent, UV‐visible spectroscopy, scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, antibacterial activity, gram‐positive bacteria Staphylococcus aureus, particle size, time 5 min to 10 min, Fe₂ O₃ ‐CuO     

Magnetic nanobiosorbent (MG‐Chi/Fe3O4) for dispersive solid‐phase extraction of Cu(II), Pb(II), and Cd(II) followed by flame atomic absorption spectrometry determination

Trace amounts of Cu (II), Pb (II), and Cd (II) in a wastewater sample were preconcentrated with a novel cross‐linked magnetic chitosan modified with a new synthesised methionine‐glutaraldehyde Schiff''s base (MG‐Chi/Fe₃O₄) as a dispersive solid‐phase extraction (DSPE) adsorbent. The adsorbed metal ions were then eluted with a specific volume of suitable solution and determined by flame atomic absorption spectrometry (FAAS). Various parameters affecting the extraction efficiency of the metal ions were investigated and optimised, including pH, amount of adsorbent, extraction time, type and volume rate of eluent, elution time, sample volume, and effect of interfering ions. The adsorption kinetics are more consistent with the pseudo‐second order model. The results were statistically interpreted and the analytical performance of the proposed method was found to have preconcentration factors of 55, 60, and 50 μg L⁻¹ for Cu(II), Pb(II), and Cd(II), respectively, limits of detection were 0.22, 0.24, and 0.10 μg L⁻¹ for Cu(II), Pb(II), and Cd(II), respectively, with a relative standard deviation (1.5%‐2.8 %), and the liner range was 5–1000 for Cu(II) and Pb(II) and 2.5–1000 for Cd(II). It was concluded that this method was suitable for successful simultaneous determination of Cu(II), Pb(II), and Cd(II) in industrial wastewater samples.     

In‐situ fabrication of zirconium–titanium nano‐composite and its coating on Ti‐6Al‐4V for biomedical applications

In this study, nanocomposite powder consisting of zirconia and titania (Zr–Ti) have been synthesised by sol–gel method, with the aim of protecting Ti‐6Al‐4V surface. A simple and low cost electrophoretic deposition (EPD) technique has been employed for coating the nanocomposite material on Ti‐6Al‐4V. The prepared nanocomposite powder was characterised for its functional groups, phase purity, surface topography by Fourier transform infrared spectroscopy, powder X‐ray diffraction and scanning electron microscopy. Further, the biocompatibility nature of the composite powder was studied by [3‐(4, 5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide] colorimetric assay and fluorescence analysis with MG63 osteoblast cell lines. The electrochemical behaviour of composite coating was investigated by potentiodynamic polarization and electrochemical impedance method. The results obtained from the electrochemical techniques indicate more corrosion resistance behaviour with increase of R _ct value with the corresponding decrease in R _dl values. From the above findings, the composite coating acts as a barrier layer against corrosion by preventing the leaching of metal ions from a dense and defect free coating. A scratch test analyser was used to assess the integrity of the coating; the lower traction force value of composite coating with increase in load has confirmed the presence of thick adherent layer on the substrate.Inspec keywords: zirconium compounds, titanium compounds, titanium alloys, aluminium alloys, vanadium alloys, nanofabrication, nanocomposites, nanoparticles, sol‐gel processing, electrophoretic coating techniques, surface topography, Fourier transform infrared spectra, X‐ray diffraction, scanning electron microscopy, X‐ray chemical analysis, fluorescence, cellular biophysics, biomedical materials, electrochemical impedance spectroscopy, corrosion resistance, corrosion protection, corrosion protective coatings, adhesionOther keywords: in‐situ fabrication, zirconium‐titanium nanocomposite powder, biomedical applications, zirconia, titania, sol‐gel method, electrophoretic deposition, EPD, functional groups, phase purity, surface topography, Fourier transform infrared spectroscopy, powder X‐ray diffraction, scanning electron microscopy, energy dispersive X‐ray analysis, biocompatibility, 3‐(4, 5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide colorimetric assay, acridine range fluorescence analysis, MG63 osteoblast cell lines, electrochemical behaviour, composite coating, potentiodynamic polarization, electrochemical impedance spectroscopy, corrosion resistance, barrier layer, leaching, defect free coating layer, scratch test analysis, adherent layer, TiAlV‐ZrO₂ ‐TiO₂      

Study of bio‐fabrication of iron nanoparticles and their fungicidal property against phytopathogens of apple orchards

Current research trends on iron nanoparticles (FeNPs) are extensively focused because of their unique magnetic and electrical properties mostly applicable in essential medical devices. However, their fungicidal property against plant pathogens is very less known until date. Present study demonstrates a green technique for blending of FeNPs by utilising aqueous extract of neem leaf (Azadirachta indica A. Juss.) as reducing agent. Various characterisation techniques such as ultraviolet (UV)–visible spectroscopy, Fourier transform infrared spectroscopy transmission electron microscopy, scanning electron microscopy and X‐ray diffraction were performed for FeNPs. The authors’ results demonstrate the more cluster formation of FeNPs with size distribution of 20–80 nm. The bio‐fabricated FeNPs showed enhanced biocidal activity against economically important phytopathogens of apple such as Alternaria mali, Botryosphaeria dothidea and Diplodia seriata. From the obtained results, it can be suggested that further delve into green synthesis of FeNPs can address future biotechnology concerns to limit the synthesis of FeNPs by conventional methods. Furthermore, the field study on pathogenic fungi can be an effective step to verify their agricultural applications.Inspec keywords: biotechnology, iron, nanoparticles, microorganisms, electric properties, agrochemicals, ultraviolet spectra, visible spectra, Fourier transform infrared spectra, transmission electron microscopy, scanning electron microscopy, X‐ray diffraction, spectrochemical analysis, nanofabricationOther keywords: biofabrication, iron nanoparticles, fungicidal property, apple orchard phytopathogens, magnetic properties, electrical properties, medical devices, plant pathogens, green technique, neem leaf, Azadirachta indica A Juss, ultraviolet‐visible spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, X‐ray diffraction, cluster formation, size distribution, biocidal activity, Alternaria mali, Botryosphaeria dothidea, Diplodia seriata, green synthesis, biotechnology, pathogenic fungi, size 20 nm to 80 nm     

Biosynthesis of reusable and recyclable CuO@Magnetite@Hen Bone NCs and its antioxidant and antibacterial activities: a highly stable magnetically nanocatalyst for excellent reduction of organic dyes and adsorption of polycyclic aromatic hydrocarbons

For the first time, through a fast, eco‐friendly and economic method, the aqueous extract of the leaf of Euphorbia corollate was used to the green synthesis of the highly stable CuO@Magnetite@Hen Bone nanocomposites (NCs) as a potent antioxidant and antibacterial agent against Pseudomonas aureus, Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae pathogenic bacteria. The biosynthesised NCs were identified using the scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy, elemental mapping, X‐ray diffraction (XRD), Fourier transforms infrared spectroscopy and UV–vis analytical techniques. Also, the radical scavenging activity using (2,2‐diphenyl‐1‐picrylhydrazyl) method was used to evaluate the antioxidant activity of the NCs. The stability of nanocatalyst was monitored using the XRD and SEM analyses after 30 days from its synthesis. Furthermore, its excellent catalytic activity, recycling stability, and high substrate applicability were demonstrated to the adsorption of the polycyclic aromatic hydrocarbons of the light crude oil from Shiwashok oil fields and destruction of methylene blue and methyl orange as harmful organic dyes at ambient temperature using UV–vis spectroscopy. Moreover, the green CuO@Magnetite@Hen Bone NCs were recovered and reused several times without considerable loss of its catalytic activity.Inspec keywords: nanobiotechnology, X‐ray diffraction, infrared spectra, catalysis, crude oil, Fourier transform spectra, ultraviolet spectra, scanning electron microscopy, dyes, catalysts, photochemistry, iron compounds, X‐ray chemical analysis, antibacterial activity, adsorption, visible spectra, microorganisms, organic compounds, reduction (chemical), nanomedicine, toxicology, recycling, chemical industryOther keywords: antioxidant activity, XRD, SEM analyses, recycling stability, polycyclic aromatic hydrocarbons, harmful organic dyes, UV–vis spectroscopy, green CuO@Magnetite@Hen Bone NCs, reusable CuO@Magnetite@Hen Bone NCs, recyclable CuO@Magnetite@Hen Bone NCs, antioxidant activities, antibacterial activities, highly stable magnetically nanocatalyst, eco‐friendly method, economic method, euphorbia corollate, green synthesis, CuO@Magnetite@Hen Bone nanocomposites, antibacterial agent, pseudomonas aureus, staphylococcus aureus, escherichia coli, klebsiella pneumoniae pathogenic bacteria, biosynthesised NCs, X‐ray spectroscopy, X‐ray diffraction, radical scavenging activity, antioxidant agent, 2,2‐diphenyl‐1‐picrylhydrazyl, catalytic activity, organic dye reduction, light crude oil, CuO     

Co–Sn–Cu oxides/graphene nanocomposites as green catalysts for preparing 1,8‐dioxo‐octahydroxanthenes and apoptosis‐inducing agents in MCF‐7 human breast cancer cells

In this work, Co–Sn–Cu oxides/graphene nanocomposite, 30–40 ± 0.5 nm in size, was synthesized by solid‐state microwave irradiation. This method presents several advantages such as operational simplicity, fast, low cost, safe and energy efficient, and suitability for production of high purity of nanoparticles. Other advantages of this method are there is no need for the use of solvent, fuel, and surfactant. Co–Sn–Cu oxides/graphene nanocomposites have been characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometer, energy‐dispersive X–ray spectroscopy, and UV–Vis spectroscopy. The synthesized nanocomposites were used as novel highly efficient catalysts for the synthesis of 1,8‐dioxo‐octahydroxanthenes at room temperature. The catalysts are recoverable and can be reused for six runs without loss of their activity. Also, the obtained nanocomposites exhibited significant anticancer activity against breast cancer cells and they could induce apoptosis in cancer cells.