Stability of nanowires in environmental aqueous solutions

Accepted Manuscript Stability of nanowires in environmental aqueous solutions

U. Klekotka, E. Zambrzycka-Szelewa, B. Kalska-Szostko PII: DOI: Reference:

S0167-7322(18)33067-8 https://doi.org/10.1016/j.molliq.2018.10.130 MOLLIQ 9875

To appear in:

Journal of Molecular Liquids

Received date: Revised date: Accepted date:

13 June 2018 24 September 2018 25 October 2018

Please cite this article as: U. Klekotka, E. Zambrzycka-Szelewa, B. Kalska-Szostko , Stability of nanowires in environmental aqueous solutions. Molliq (2018), https://doi.org/ 10.1016/j.molliq.2018.10.130

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT Stability of nanowires in environmental aqueous solutions U. Klekotka, E. Zambrzycka-Szelewa, B. Kalska-Szostko* Institute of Chemistry, University of Bialystok, Ciolkowskiego 1K, 15-245 Bialystok, Poland *corresponding author: [email protected] Keywords: nanowires, magnetic nanomaterials, stability

PT

Abstract

PT E

D

MA

NU

SC

RI

In presented in this paper studies, nanowires of pure metallic Fe, and one modified at the surface with iron oxide, Cu, and Ag layers were examined for its resistance in several environmental solutions (wastewaters, river water, and milk). Tests included investigations of the stability of nanowires in these solutions, and therefore their potential applicability as water filters, or food storage sensors, constituents of packages, etc. On the other hand, it shows its potential circulation in a human environment before final degradation. Nanowires were electrodeposited in the alumina oxide matrix and their diameter was determined by the pore size to be around 140±20 nm. The length of nanostructures is adjustable by deposition time up to few µm. Nanowires physicochemical properties after treatment in mentioned solutions were measured by transmission electron microscopy, infra-red spectroscopy, and X-ray diffraction. Solutions after the experiment were analyzed by flame atomic absorption spectroscopy. Interaction with selected solutions shows that the highest concentration of Fe was found in milk and treated sewage and Ag only transfers to untreated wastewater and Cu was found in significant amounts in milk and untreated sewage. In addition, metallic layers prevent dilution of Fe core with the exception of two cases: untreated sewage with Ag shell, and milk with Cu shell.

CE

The durability tests of nanowires in environmental liquids and its resistance to real solutions as well as the dissolution was established. The indication of recycling processes of nanowires was achieved.

1. Introduction

AC

A continuously growing interest in nanotechnology and its achievements have resulted in the development of a large variety of materials with different composition and shapes in nanoscale [1-3]. It can be stated that nanostructures assist us in every-day life by its presence in many materials. Studies of elongated structures such as wires or tubes became the entertaining subject of not only fundamental research but technological development [4-11]. A strong interest in magnetic nanomaterials is based on their specific wide range application, demanding not only particular composition but also extraordinary magnetic behavior, for example as IT devices parts, memories storage media, sensors, and logical devices, flexible solar cells, and composites, transistors, race track memories [12-15], etc. Other important applications are evident in the field of medicine, where nanomaterials can play various roles from drug delivery media to structural material in biological composites and sensors as well as biological transport systems, or limitation of the growth of bacteria [16-19]. Recently environmental science via water cleaning, adsorption of oil spoils, catalysis or chemical vapor detection [20-22], and food industry [23] has become a promising field for usage of 1

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

MA

NU

SC

RI

PT

nanotechnological advancements. Therefore, one of the top priority subjects is heavy metals detectors sensitive for example to Pb, Cd, Cr, and Zn elements as well as its removal from food or water via purification systems [24]. The most important advantages of nanomaterials which results in its so wide range popularity, in comparison to the conventional one, is its huge increase of surface active area [19] which is especially vague when sensors and actuators applications are considered. As described above a wide range of applications causes that nanostructures will become more and more present in our environment and finally resulting in a waste. Therefore its resistance in unchanged form determines not only an accessibly useful lifetime of the products (nanostructures as such or its composites) but also its presence and circulation in the environment. Many scientists dedicate special efforts to achieve multifunctional materials with a simple synthetic procedure and easy processing for subsequent applications because nanoscale products allow to ultimate nanosensors with a sensing possibility going down to a single molecule. Self or templeorganized nanowires-based devices can lead to the fabrication of very promising, efficient, low cost and large dimension sensors [25]. Chemical and electrochemical preparation[26-28] methods are one of the options to obtain a new class of nanomaterials, which are significantly less expensive in production compared to many others. Some of nanostructures fabrication procedures employ physical procedures and need to use very sophisticated devices like laser vaporization, molecular beam epitaxy or sputtering. Therefore, it is useful from the economical point of view to develop new approaches that are less expensive, or large scale applicable and can lead to similar or even better final products. Wet chemistry and electrochemistry are one of the promising powerful options in such an instance. Electrochemistry allows for the depositing of materials in many different forms from solutions containing proper ingredients on a large variety of surfaces regardless of composition and shape. Hybrid nanomaterials and nanocomposites have become trendy to be studied because of the enhancement of their magnetic, electrical, mechanical properties, and optical sensitivity [29], due to their constituents synergic interaction or special shape. Quasi one-dimensional structures have an advantage over the round ones because there is the possibility to manipulate their morphology and obtain zone wise selective interaction with the environment and for some purposes, easier surface modification [30-31]. The existence of so many pros of nanomaterials diminish considerations of any negative influence and such studies become marginal. We have decided partially to face the problem and some studies have been performed [32-33]. The wide use of iron-based nanomaterials allows us to choose these as an example material for studies of so complex phenomena as well as our own interest in these systems [34]. In the literature, there are some nanowires stability investigations but it considers different approaches of selected systems [35-37]. Therefore, there is not much data available which show degradation processes and if any exist it is devoted to very different kind of nanomaterials and various interacting/influencing stimuli. Available scattered data did not show much on nanowires stability in environmental media and its remediation in waste and river water or milk is even less known. Therefore we have decided to study such a subject. We have tested up to now environmental stability [38-39] and heavy metal detection [40] of nanoparticle-based composites. However, little is known about how Fe nanowires will behave in such case. Therefore, in this paper pure Fe and three types of core-shell nanowires are examined in four environmental solutions (treated and untreated wastewater, river water, and milk). This is an extension of our previous studies of the stability of round nanoparticles and nanowires in various model solutions [32,33,38,39]. Experimental 2

ACCEPTED MANUSCRIPT 2.1. Materials and apparatus To obtain Fe and iron oxide, Cu- or Ag- modified nanowires following chemicals originating from POCH were used: H3PO4, CrO3, FeSO4·7H2O, CuSO4·7H2O, AgNO3, FeCl3·6H2O H3BO3, ascorbic acid, NaOH, acetone, and distilled water.

SC

RI

PT

The FT-IR (Fourier transform infrared spectroscopy) spectra were collected in reflection mode (ATR) at room temperature (RT) by Nicolet 6700 Infrared spectrometer working in the spectral range between 500-4000 cm-1. Morphology of the nanowires was imaged by transmission electron microscope (TEM), (model: FEI Tecnai G2 X-TWIN 200kV) and scanning electron microscope (SEM) (model: Inspect 2000). Analysis of the wire crystal structures was done by X-ray diffractometer (XRD) Agilent Technologies SuperNova equipped with a Mo micro-focused source (Kα2=0,713067 Å). Solutions after wetting tests were analyzed by Flame Atomic Absorption Spectroscopy (FAAS method) with the use of Solar M6 Spectrometer (specification of the measurement: 1.2 L/min gas flow, burner height of 13.4 mm, air-acetylene flame) to evaluate the amount of Fe, Cu, and Ag elements. 2.2. Preparation of nanowires

D

MA

NU

All types of nanowires were fabricated in anodic aluminum oxide (AAO) matrix obtained in a 3-step anodization procedure resulting with diameter pore size of about 140±20 nm [41]. In the studies presented here, pure Fe, and Fe nanowires covered with iron oxide, Cu, or Ag layer, were obtained. Each type of nanowires was electrodeposited from the solution composed of FeSO4·7H2O, FeCl3·6H2O, H3BO3 and ascorbic acid. The electrodeposition process was conducted for 10 minutes in DC mode, with a current value of 10 mA. After deposition, the AAO matrix was dissolved in 1M NaOH solution, and the obtained nanowires were washed three times with distilled water and acetone.

CE

PT E

To obtain Fe@FeO nanowires, empty AAO matrixes were at first placed in the solution of 0.2M H2CrO4 and 0.4M H3PO4 for 5 minutes, then washed with distilled water and located in 0.15M Fe(NO3)3 solution for 180 min. Then, matrixes were removed from the solution and placed in the furnace for 1200 min at T=60°C and then for 180 min at T=550°C. The obtained tubes were then filled with Fe as it was described in the section above [34].

AC

Covering of Fe nanowires with Cu and Ag shell was done by short wetting of pristine nanowires in 0.1M CuSO4, or 0.1M AgNO3 solution, for around 5 minutes. Then, the solution was removed and modified nanowires were washed with distilled water and left overnight for drying [42]. 2.3. Stability and applicability tests in environmental solutions All describe above kinds of nanowires were immersed for three weeks in four different types of solutions: untreated steward, treated steward, river water, and milk (0,5% fat). Both classes of wastewaters were obtained from the sewage treatment plant. Untreated steward was used in the experiment as it was obtained from the plant while treated one was centrifuged to remove part of the solid constituents. River water was taken from the local river and used without additional treatment. 0.5% fat milk was obtained from the commercially available product of the local factory. This is an extension of our previous studies, where pure and core-shell nanowires were tested in model solutions (distilled water, citric acid, saline, ethanol, wine) [32,33]. Analog studies were also done on magnetite nanoparticles. Selection of environmental solutions was done based on the probability of the presence

3

ACCEPTED MANUSCRIPT of worn-out nanowires in chosen liquids. Its resistance in such a milieu indicates also a possibility of its recirculation and eventual fatal effect on a human being as well as fauna and flora. 2. Results and discussion 2.1. AAS and gravimetric results

PT

Primary studies assume a comparison of the masses, of used in experiment nanowires, before and after treatment in every solution what will suggest eventual dissolving of inorganic cores. Results are presented in Table 1. Where masses are summarized with the amount of Fe, Ag and Cu elements obtained from FAAS.

Fe NW’s

Untreated sewage River water Milk

Before [mg] ±0.1 5.5 5.7 5.1 5.2

After [mg] ±0.1 5.8 6.3 5.6 16.9

AAS [mg] ±0.01 [Fe]

0.08 0.02 0.0 1.07

After [mg] ±0.1 4.9 5.9 8.1 8.7

Before [mg] ±0.1 5.1 5.3 5.2 5.2

After [mg] ±0.1 5.4 11.6 5.3 14.2

Ag@Fe NW’s

River water Milk

D

Untreated sewage

PT E

Treated sewage

[Fe] AAS [mg] ±0.01 0.0 0.4 0.0 0.0

[Ag] AAS [mg] ±0.01 0.1 0.8 0.3 0.0

FeO@Fe NW’s

Before [mg] ±0.1 5.3 4.8 5.0 5.1

NU

Treated sewage

After [mg] ±0.1 6.5 5.2 7.6 12.1

MA

Solutions

Before [mg] ±0.1 5.1 5.0 5.0 5.1

SC

RI

Table 1. Summary of gravimetric and FAAS results (for Fe, Ag and Cu) of nanowires and tested solutions before and after 3 weeks treatment in environmental media. Data are shown in respect of wires kind – column, and the solution - row.

AAS [mg] ±0.01 [Fe] 0.73 0.16 0.02 2.21

Cu@Fe NW’s [Fe] AAS [mg] ±0.01 0.0 0.0 0.0 3.7

[Cu] AAS [mg] ±0.01 0.9 1.2 0.9 2.8

AC

CE

From the results presented in Table 1, it can be seen, that the addition of Ag or Cu shell on the surface of the nanowire causes an increase in the iron core stability. As it is proved by the FAAS measurement, where almost no Fe atoms were found in the solutions. It means, that a noble metal layer prevents the iron core from degradation and dissolution. Results suggest that wires have to be tightly covered with Ag, or Cu shell. Covering nanowires by iron oxide shell causes a decrease in their stability in the tested solutions. Significant mass change (increase) of the nanowires treated in milk is caused by deposition of some organic compounds presented in the milk onto the surface. It should be also mentioned, that after the third week of nanowires wetting, their magnetic properties become less pronounced, what can be observed by the weaker reaction on the external magnetic field presence, therefore it suggests oxidation to nonmagnetic iron oxides or hydroxides. Comparison of described here wires modification to previous studies [32,33], allow to conclude, that Ag and Cu outermost layers protect wire core better than other tested shells (e.g. silica, iron oxide). This is an important message when the application is considered and the strength of magnetic interaction needs to be supported. On the other hand, it means that any surface modifications of nanomaterials by metallic layer increase the hazardous potential of the structures. 4

ACCEPTED MANUSCRIPT 2.2. TEM and SEM imaging

PT E

D

MA

NU

SC

RI

PT

Reference and treated nanowires were examined by TEM or SEM, to see the morphology of the structures and its potential modification after post-treatment. For the comparison of results series imaged by TEM (first row) and SEM (another row) was selected. Obtained pictures are presented in Fig. 1.

CE

Fig. 1. TEM (for Fe NW’s), and SEM images (for Ag@Fe, Cu@Fe, and FeO@Fe NW’s) of reference and treated in tested solutions nanowires. Row - show kind of tested material, columns – environmental liquids.

AC

Depicted in Fig. 1 TEM images of Fe NW’s treated in tested solutions demonstrates that nanostructures preserve its elongated morphology after each treatment. However, in some cases, evidence of surface modification is obvious. A similar conclusion about morphology conservation can be done for Ag@Fe, Cu@Fe, and FeO@Fe NW’s based on SEM studies. In every image, nanowires can be clearly seen. However here, much more residuals from tested solutions can be observed, but it is due to the sample preparation protocol that avoids interaction with other solutions, to clear the wires. Therefore, all solid ingredients from the solutions left on the sample holders during SEM samples preparation in contrary to TEM probes. 2.3. EDX analysis Nanowires before tests were examined by EDX, to see if the respective shell was obtained on their surface. Collected spectra for core-shell samples are presented in Fig. 2.

5

PT E

D

MA

NU

SC

RI

PT

ACCEPTED MANUSCRIPT

CE

Fig. 2. EDX analysis of (A) Fe, (B) Fe@Ag, and (C) Fe@Cu nanowires. Since FeO@Fe nanowires the same elemental composition as pure Fe its EDX spectrum is not presented here.

AC

It is seen that modification of wires surface was done with success. Either wire were covered by requested layers. Composition confirms that only surface was covered by Ag or Cu because its content is much lower in comparison to the core. More studies on core-shell composition of the nanowires were published elsewhere [34]

2.4. X-ray diffraction Each type of tested nanowires was measured by X-ray diffraction to follow evolution in their crystalline structure due to the oxidation process induced by different environmental exposure. In Fig. 3A reference XRD patterns of nanowires are presented, its crystal structure before treatment. In each diffractogram, relevant Müller (hkl) indexes were assigned which assumes the presence of particular layers. The most intense are signals for bcc Fe (110)(200)(211)(220)(310)[43] but also Ag shell can be seen as well as a respective pattern (110)(200)(220)[44]. Similarly, traces of Cu lies almost at the same position due to likeness in a symmetry of crystal structure and cell parameters 6

ACCEPTED MANUSCRIPT

PT E

D

MA

NU

SC

RI

PT

[45]. Since Cu patterns are very weakly present that can indicate rather an amorphous growth. In Fig. 3B, C, D and E, diffractograms of Fe, Cu@Fe, Ag@Fe, and Fe-ox@Fe nanowires wetted for 3 weeks in the treated and untreated wastewaters, river water, and milk and were depicted in the same sequence as in Fig. 3A, respectively.

Fig. 3. XRD spectra of A) reference nanowires; after 3 weeks wetting in B) treated wastewater; C) untreated wastewater, D) river water, and E) milk. Above peaks, appropriate phase notations are included (fcc Ag, and Cu in green, bcc Fe in black and magnetite/maghemite in red).

AC

CE

X-ray spectra clearly indicate, that treatment of nanowires by specific conditions, can completely damage their initial crystalline structure and transfer into Fe oxides - maghemite (in most) and hydroxides. However, the degree of the degradation is very different. The development of oxides also is very miscellaneous. In this studies, the most destructive environment appears to be the river water, where only Ag@Fe nanowires remained unchanged and supported the observation that the Ag layer prevents wire degradation. The lowest stability shows Cu@Fe nanowires because in every type of tested environment it oxidizes, to rather a complex system with the domination of magnetite/maghemite [46] which most intense peaks can be found. It means that Cu shell did not protect the iron core, which is in agreement with the observation that Cu dissolves in tested solutions most. Therefore, the oxidation process starts very early in each selected environment. In the destruction process, step-by-step oxidation can be observed, an indication of maghemite and hematite presence can be found. 2.5 IR spectroscopy

7

ACCEPTED MANUSCRIPT

PT E

D

MA

NU

SC

RI

PT

Fe nanowires were further analyzed by IR spectroscopy to observe changes taking place on their surface, after wetting process. Representative spectra of nanowires after 3 weeks of wetting are collected in Fig. 4. Each type of wires is plotted in a separate frame.

AC

CE

Fig. 4 IR spectra of pure Fe (A), and core-shell nanowires before and after treatment in all studied environmental solutions (B) FeO@Fe; (C) Ag@Fe; (D) Cu@Fe NW’s. The most intense bands are assigned and its origin is described in Table 2. Observed in IR spectra (Fig. 4) signals, are recognized and described in Table 2. Its analysis allows concluding, that all Fe nanowires oxidase in tested environments to maghemite and lepidocrocite. Oxidation effect can be observed in every case, but its intensity depends on the type of coating of Fe nanowires with Ag or Cu metallic shells or Fe oxide. All spectra show in addition to Fe-O bonds signals assigned to O-H, C-H, C=O, and N-H vibrations, what suggests that compounds present in the tested solutions adsorb to the surface of the nanowires. Analyzed by IR surface oxidation confirm wires degradation and composition described by other methods. Moreover, in Fig. 4C low-intense but sharp signals at around 2651 cm-1 present in treated and untreated wastewater suggest S-H bonds. It is in good agreement with the fact of the high affinity of thiols to Ag surface and its very probable presence in wastewater. Therefore properly designed and modified nanowires can serve as detectors of the presence of some specific compounds in the solution and can enlarge the scope of application of these kinds of materials in environmental science. 8

ACCEPTED MANUSCRIPT Table 2. Assignment of the appropriate bonds which corresponds to the observed signals on IR spectra with their references. Ref. [47] [47] [47] [47] [47] [47] [48] [47] [38]

PT

Assignment O-H in water C-H S-H C=O, stretching N-H, C-H, rocking Fe-O Lepidocrocite C-H, deformation Fe-O, maghemite

RI

Wavenumber [cm-1] ̴3300 2923-2837 2651-2657 ̴1725 1527 1390-1362 1037-941 878-863 651-693

SC

3. Conclusion

AC

CE

PT E

D

MA

NU

In the paper degradation of Fe based core-shell nanowires as a consequence of its contact with environmental solutions were studied by TEM, SEM, IR, EDX FAS, and XRD. Each method gives results which are consistent with other. The presented data show that Fe nanowires covered by Ag, or Cu layer have become more resistant to dissolution in comparison to naked one or Fe-ox covered. Metallic layer prevents diffusion of Fe to the solution. The amount of Ag in the solution after wetting is also very low, which is in contrary to Cu which dissolves much more extensive. Presence of Fe-ox layer does not protect migration of Fe into solution. The appearance of Fe, however, can be due to the dissolution of Fe-ox, not Fe. The weakening of the interaction of structures with external magnetic field suggests oxidation of Fe core to nonmagnetic Fe-ox without leakage of Fe atoms into solution. Such observations have advantages and disadvantages. Primarily, the Fe nanowires which get into waste will always be degraded and loose its magnetic properties but its removal can be much more difficult. Further degradation of Fe oxides can be also very long as it was observed for iron oxide nanoparticles [38,39]. Cu can be dissolved from the shell and be present in the ecosystem as not very toxic spices. However, the presence of Ag can influence very strongly the local environment due to its antibacterial properties. Secondly, the unexpected wetting of the sensors can change its functionality and therefore destroy its sensing capability. Ag surface demonstrates high affinity/selectivity to thiol compounds, which suggest that such a system is a good detector of this type of compounds. Presented studies, therefore, can be treated as an extension of the basic knowledge about properties of nanowires as such but also can be an origin of studies on the degradation of nanomaterials and its environmental pollution as well as an indication of the problem how to treat nanomaterials which possess interesting properties when they finish its primary functions. Authors are aware that studied subject is only a tip of the iceberg and problems with nanostructures storage or recycling needs far more investigations on many levels. As it is seen nanoscale Fe is much less resistant to the oxidation in comparison to bulk materials. The transformation to iron oxide is very fast due to a large surface area in comparison to the volume which is exposed to the destructive environment. However, the transformation of the one oxide into another one can be much slower than primary process as it is seen for Fe oxide nanoparticles. Nevertheless, a transformation of Fe into oxide causes changes of its magnetic characteristic what is important from the application point of view. 9

ACCEPTED MANUSCRIPT Acknowledgment Authors acknowledge to M. Stanislawajtys and P. Bogdanowicz for preparation of nanowires and lab assistants. The work was partially financed by EU found via a project with contract number POPW.01.03.00-20.034/09-00, POPW.01.03.00-20-004/11-00 and by National Science Center, Poland project number UMO-2014/13/N/ST5/00568. Literature

PT

[1]. Pereira, A., Palma, J. L., Vázquez, M., Denardin, J. C. & Escrig, J. A soft/hard magnetic nanostructure based on multisegmented CoNi nanowires. Phys. Chem. Chem. Phys. 17, 5033–8 (2015).

RI

[2]. Lv, R. et al. Long continuous FeNi nanowires inside carbon nanotubes: Synthesis, property and application. J. Phys. Chem. Solids 69, 1213–1217 (2008).

SC

[3]. Vaseem, M., Umar, A. & Hahn, Y. ZnO Nanoparticles : Growth, Properties, and Applications. Metal Oxide Nanostructures and Their Applications 5, (2010).

NU

[4]. Thongmee, S., Pang, H. L., Ding, J. & Lin, J. Y. Fabrication and magnetic properties of metallic nanowires via AAO templates. J. Magn. Magn. Mater. 321, 2712–2716 (2009).

MA

[5]. Reich, D. H. et al. Biological applications of multifunctional magnetic nanowires (invited). J. Appl. Phys. 93, 7275–7280 (2003). [6]. Hannour, a. et al. Atomic-scale investigation and magnetic properties of Cu80Co20 nanowires. J. Appl. Phys. 110, 63921 (2011).

D

[7]. M.I. Irshad, et al., AIP Conference Proceedings 1669 (2015) 020006

PT E

[8]. S.P. Rwei et al., Journal of Nanomaterials 2013 (2013) 745746 [9]. M. Krajweski et al., Nukleonika 60 (2015) 87

CE

[10]. P. Hiralal et al., Nanotechnology 19 (2008) 455608 [11]. J.J. Vivos-Castro et al., J. Materi. Sci.: Mater. Elektron. 25 (2014) 2835

AC

[12]. Cowburn, R. P., Welland, M. E. Room Temperature Magnetic Quantum Cellular Automata. Science (80-. ). 287, 1466–1468 (2000). [13]. Jo, C., Lee, J. Il & Jang, Y. Electronic and magnetic properties of ultrathin Fe-Co alloy nanowires. Chem. Mater. 17, 2667–2671 (2005). [14]. Chen, J., Wang, Y. & Deng, Y. Highly ordered CoFe2O4 nanowires array prepared via a modified sol-gel templated approach and its optical and magnetic properties. J. Alloys Compd. 552, 65– 69 (2013). [15]. M.A. Zeeshan etal., Adv. Funct. Mater. 23 (2013) 823-831 [16]. Lin, Y. W., Huang, C. C. & Chang, H. T. Gold nanoparticle probes for the detection of mercury, lead and copper ions. Analyst 136, 863–871 (2011). 10

ACCEPTED MANUSCRIPT [17]. D. Wang et al., Environmental Science:Nano 5(2018) 1096 [18]. H.-W. Liou et al., J. Biomaterials and Nanobiotechnology 1 (2010)50 [19]. Y.P. Ivanov et al., Scientific Reports 6 (2016) 24189 [20]. Youssef, A. M. & Malhat, F. M. Selective Removal of Heavy Metals from Drinking Water Using Titanium Dioxide Nanowire. Macromol. Symp. 337, 96–101 (2014). [21]. B.Y. Yoo et al., Water Science and Technolgy 55 (2007) 149-156

PT

[22]. S. Saif, et al., Nanomaterials 6 (2016) 209

RI

[23]. Chellaram, C. et al. Significance of Nanotechnology in Food Industry. APCBEE Procedia 8, 109– 113 (2014).

SC

[24]. Pirouz, M. J., Beyki, M. H. & Shemirani, F. Anhydride functionalised calcium ferrite nanoparticles: A new selective magnetic material for enrichment of lead ions from water and food samples. Food Chem. 170, 131–137 (2015).

NU

[25]. Haun, J. B., Yoon, T. J., Lee, H. & Weissleder, R. Magnetic nanoparticle biosensors. Wiley Interdiscip. Rev. Nanomedicine Nanobiotechnology 2, 291–304 (2010).

MA

[26]. Reddy, S. M. et al. Electrochemical Synthesis of Magnetostrictive Fe-Ga/Cu Multilayered Nanowire Arrays with Tailored Magnetic Response. Adv. Funct. Mater. 21, 4677–4683 (2011).

PT E

D

[27]. Forrer, P., Schlottig, F., Siegenthaler, H. & Textor, M. Electrochemical preparation and surface properties of gold nanowire arrays formed by the template technique. J. Appl. Electrochem. 30, 533– 541 (2000).

CE

[28]. Solmaz, R. & Kardas, G. Electrochemical deposition and characterization of NiFe coatings as electrocatalytic materials for alkaline water electrolysis. Electrochim. Acta 54, 3726–3734 (2009). [29]. Salazar-Romero, M. Y. et al. Nonlinear optical properties of dielectric nanocolloids: Particle size and concentration effects. J. Nonlinear Opt. Phys. Mater. 25, 1650048 (2016).

AC

[30]. Wang, X. et al. Room-Temperature Surface Modification of Cu Nanowires and Their Applications in Transparent Electrodes, SERS-Based Sensors, and Organic Solar Cells. ACS Appl. Mater. Interfaces 8, 28831–28837 (2016). [31]. F. Potolsky, et al., Nanomedicine 1 (2006) 15 [32]. Kalska-Szostko, B., Wykowska, U., Basa, A. & Zambrzycka, E. Stability of core–shell nanowires in selected model solutions. Appl. Surf. Sci. 332, 599–605 (2015). [33]. Kalska-Szostko, B., Wykowska, U., Piekut, K. & Zambrzycka, E. Stability of iron (Fe) nanowires. Colloids Surfaces A Physicochem. Eng. Asp. 416, 66–72 (2013). [34]. Kalska-Szostko, B., Orzechowska, E. & Wykowska, U. Organophosphorous modifications of multifunctional magnetic nanowires. Colloids Surfaces B Biointerfaces 111, 509–516 (2013). 11

ACCEPTED MANUSCRIPT [35]. W. Zhou, et al. Nano Lett. 14 (2014) 1614 [36]. D.L. Zagorskiy, et al. J. Surf. Invest. X-ray, Synch. And Neutr. Tech. 11 (2017) 99 [37]. C. Mayousse, et al. Nanoscale 7 (2015) 2107 [38]. Kalska-Szostko, B., Wykowska, U., Piekut, K. & Satuła, D. Stability of Fe3O4 nanoparticles in various model solutions. Colloids Surfaces A Physicochem. Eng. Asp. 450, 15–24 (2014).

PT

[39]. Kalska-Szostko, B., Wykowska, U., Satuła, D. & Zambrzycka, E. Stability of core-shell magnetite nanoparticles. Colloids Surfaces B Biointerfaces 113, 295–301 (2014).

RI

[40]. Klekotka, U ; Winska, E; Zambrzycka-Szelewa, E; Satula; Kalska-Szostko B., Heavy-metal detectors based on modified ferrite nanoparticles, Beilstein Journal Of Nanotechnology 9 (2018) 762770

SC

[41]. Kalska-Szostko, B. et al. Electrochemical deposition of nanowires in porous alumina. Acta Phys. Pol. A 115, 542–544 (2009).

NU

[42]. B. Kalska-Szostko; Klekotka, U, Satula, D, Core-shell magnetic nanowires fabrication and characterization, Applied Surface Science 396 (2017) 1855-1859

MA

[43]. Charlot, F., Gaffet, E., Zeghmati, B., Bernard, F. & Niepce, J. C. Mechanically activated synthesis studied by X-ray diffraction in the Fe–Al system. Mater. Sci. Eng. A 262, 279–288 (1999).

D

[44]. Sinha, A. & Sharma, B. P. Preparation of silver powder through glycerol process. Bull. Mater. Sci. 28, 213–217 (2005).

PT E

[45]. K. Zhang, I. V. Alexandrov, R. Z. Valiev, and K. Lu, Structural characterization of nanocrystalline copper by means of x-ray diffraction, Journal of Applied Physics 80 (1996) 5617

CE

[46]. Ghandoor, H. El, Zidan, H. M., Khalil, M. M. H. & Ismail, M. I. M. Synthesis and Some Physical Properties of Magnetite (Fe 3 O 4 ) Nanoparticles. Int. J. Electrochem. Sci 7, 5734–5745 (2012)

AC

[47]. Coates, J. Interpretation of Infrared Spectra, A Practical Approach Interpretation of Infrared Spectra, A Practical Approach. Encycl. Anal. Chem. 10815–10837 (2000). doi:DOI: 10.1002/9780470027318 [48]. Balasubramaniam, R. & Ramesh Kumar, A. V. Characterization of Delhi iron pillar rust by X-ray diffraction, Fourier transform infrared spectroscopy and Mossbauer spectroscopy. Corros. Sci. 42, 2085–2101 (2000).

12

ACCEPTED MANUSCRIPT

Figure caption: Fig. 1. TEM (for Fe NW’s), and SEM images (for Ag@Fe, Cu@Fe, and FeO@Fe NW’s) of reference and treated in tested solutions nanowires. Row - show kind of tested material, columns – environmental liquids.

RI

PT

Fig. 2. EDX analysis of (A) Fe, (B) Fe@Ag, and (C) Fe@Cu nanowires. Since FeO@Fe nanowires the same elemental composition as pure Fe its EDX spectrum is not presented here.

NU

SC

Fig. 3. XRD spectra of A) reference nanowires; after 3 weeks wetting in B) treated wastewater; C) untreated wastewater, D) river water, and E) milk. Above peaks, appropriate phase notations are included (fcc Ag, and Cu in green, bcc Fe in black and magnetite/maghemite in red).

Table caption:

PT E

D

MA

Fig. 4 IR spectra of pure Fe (A), and core-shell nanowires before and after treatment in all studied environmental solutions (B) FeO@Fe; (C) Ag@Fe; (D) Cu@Fe NW’s. The most intense bands are assigned and its origin is described in Table 2.

AC

CE

Table 1. Summary of gravimetric and FAAS results (for Fe, Ag and Cu) of nanowires and tested solutions before and after 3 weeks treatment in environmental media. Data are shown in respect of wires kind – column, and the solution - row.

Table 2. Assignment of the appropriate bonds which corresponds to the observed signals on IR spectra with their references.

13

ACCEPTED MANUSCRIPT Highlights

CE

PT E

D

MA

NU

SC

RI

PT

The durability tests of nanowires in environmental liquids was done. The resistance of nanowires to real solutions was established The influence of environmental liquids on the dissolution of nanowires was tested. The indication of recycling processes of nanowires was achieved.

AC

   

14