The effect of additive chemicals on synthesis of bismuth nanoparticles

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ScienceDirect Materials Today: Proceedings 5 (2018) 14057–14062

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SACT 2016

The effect of additive chemicals on synthesis of bismuth nanoparticles K. Petsoma,b, A. Kopwitthayac,*, M. Horphathumc, J. Kaewkhaoa,b, N. Sangwaranateec a

Center of Excellence in Glass Technology and Materials Science (CEGM), Nakhon Pathom Rajabhat University, Nakhon Pathom 73000, Thailand b Physics Program, Faculty of Science and Technology, Nakhon Pathom Rajabhat University, Nakhon Pathom 73000, Thailand c National Electronics and Computer Technology Center, Pathum Thani 12120, Thailand c Applied Physics, Faculty of Science and Technology, Suan Sunandha Rajabhat University, Bangkok 10300, Thailand

Abstract Bismuth nanostructures are of interest due to unique properties such as strong diamagnetism, high magnetoresistance under magnetic field, as well as biocompatibility compared with lead. Previous study have reported a relationship of obtained nanostructures and synthesized conditions including pH, temperature and time during nucleation. Most of them confront difficulties on size controlling, particularly in large volume synthesis. Therefore, the goal of this work is to simplify the synthesis method by studying an effect of additive chemicals which are introduced to a growth solution before nanocrystal formation. Ascorbic acid, dioctyl sulfosuccinate sodium salt (AOT) and ethanol were chosen to slow down the reaction or disturb the micellar template. The study has shown that size of nanoparticles can be easily tuned by adding different amount of aforementioned chemicals. According to different role in nanocrystal forming mechanism, more ascorbic acid tends to increase diameter of obtained particles. Oppositely, more AOT has shrunk synthesized particles due to packed micelles. Loose micelles are found in ethanol experiment leading to bigger particles in size. In addition, crystalline structure exhibited the diffraction plane at (012), (104), and (110) with X-Ray diffraction (XRD) analysis. Field emission scanning electron microscopy (FE-SEM) was used to determine morphology of nanoparticles, and also size distribution was confirmed by nanoparticle tracking analysis (NTA). We also found the quench of nanocrystal formation in the presence of high concentration of ethyl alcohol. © 2018 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Selection and/or Peer-review under responsibility of SACT 2016. Keywords: Ascorbic acid; Docusate sodium salt; ethanol; room temperature synthesis

* Corresponding author. Tel.: +662-564-6900 E-mail address: [email protected] 2214-7853 © 2018 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Selection and/or Peer-review under responsibility of SACT 2016.

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1. Introduction Metal nanomaterials have attracted a great deal of interest because its optical [1-3], catalytic [2], magnetic [2-4], and electrical [4] properties depends mainly on size and shape. Bismuth is one of the most interesting materials which can transit from semi-metal to semiconductor when its crystallite is small enough [5]. Due to its highly anisotropic Fermi surface, low carrier concentration, small effective mass, and long mean free path of the charge carriers, bismuth nanoparticles presents outstanding catalytic and photocatalytic properties. With aforementioned advantages, bismuth nanoparticles is widely used in various potential applications including antimicrobial agent in biomedical sciences [6], X-Ray radiation therapy [7], thermoelectric sensor [8] and heavy-metal ion detector [9]. To date, chemical approaches are widely used to obtain bismuth nanoparticles. Typically, several methods such as solvent-less methods [10], high temperature hydrothermal [11], pH-Dependent [12], and inversed micelles methods [13] can be used to prepare bismuth nanostructures. However, most of them require high-temperature and long aging time in the process. In this work, we simplify the protocol by studying the additive chemicals to control nanostructures forming in the nucleation process. Our protocol can be done at room temperature with the use of sodium borohydride (NaBH4) as reducing agent. Different chemical such as ascorbic acid, dioctyl sulfosuccinate sodium salt (AOT), and ethanol were introduced to the reaction to disturb nanocrystal formation. Different sizes of obtaining bismuth nanoparticles, then were successfully prepared depending on concentration of the additives. Besides, our study also found the effect of additives on volume of the prepared nanopowder. This finding will be critical information of nanopowder mass production especially in industrial-scale preparation. 2. Material and methods 2.1 Materials Bismuth nitrate pentahydrate (Bi(NO3)3•5H2O) purchased from CARLO ERBA Reagents. Nitric acid (HNO3, 70%) purchased from J.T.Baker. Sodium hydroxide (NaOH) purchased from Ajax Finechem. Sodium oleate (SOA) purchased from TOKYO CHEMICAL INDUSTRY. Tartaric acid (TA, H2C4H4O6) purchased from Ajax Finechem. Ascorbic acid (C6H8O6) purchased from Sigma-Aldrich. Dioctyl sulfosuccinate sodium salt (AOT) purchased from Sigma-Aldrich. Ethanol (C2H6O 99.99%) purchased from MERCK. And sodium borohydride (NaBH4) purchased from Fluka Analytical. All the reagents were used without further purification. 2.2 Synthesis of Bismuth nanoparticle Bismuth nanoparticles were synthesized under an aqueous condition. In a typical preparation, the mixture containing 40 ml (0.01 M) of Bi(NO3)3•5H2O, 40 ml (0.04 M) of H2C4H4O6 and 6 ml of HNO3 were stirred with maximum speed. Then, 0.4 g of NaOH in 20 ml distilled water was added to the suspension and stirred at room temperature to get a transparent solution. Use 20 ml of the mixture above, then, 10 ml (2 mM) of SOA was added into the solution. In the additive study experiments, additive chemicals were introduced to the mixture at various concentrations. For example, 100-500 μl of ascorbid acid (0.1mM), 100-500 μl of AOT (0.1mM), and ethanol in distilled water at ratio of 0:10, 2:8, 5:5, 8:2. In the final step, 800 μl (7 mM) of fresh NaBH4 solution was quickly added. Upon the addition of reducing agent, the solution was observed to change from cloudy-colorless suspension to black solution. The resulting black precipitates were filtered, and then washed with distilled water and absolute ethanol for several times to remove excess chemicals. Bismuth nanopowder was dried at 80 °C for 15 min. 2.3 Characterizations The crystallization of bismuth nanoparticles were determined by X-ray diffraction (XRD) using a Rigaku, Japan/ TTRAX III diffractometer with Cu K1 (λ= 1.5406A˚) radiation in a 2θ range of 10–80 at room temperature. The morphology and particle size of bismuth nanoparticle were characterized by field emission scanning electron microscopy (FE-SEM), Hitachi SU-8030 with power of electron beam 5 kV. All samples were taken at the same

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condition of power source. Size distribution measurements were also carried out by counting at least 500 particles. The hydrodynamic diameters of nanoparticles were measured by Nanosight-NS500 with nanoparticle tracking analysis software, NTA 3.0. All samples were dissolved in 2% Tween 80 and sonicated for 5 minutes before measurement. 3. Results and discussion In the micellar system, different chemicals introduced to solution can play different role in the reaction. Scheme 1 demonstrates the mechanism of nanocrystal formation in this report. When optimum concentration of SOA is dissolved in water, nanomicellar are formed [14]. In the presence of AOT, the micelle will be packed due to the increasing of surfactant concentration. Oppositely, ethanol has ability to loose a micelle because alkyl chain of the surfactant is soluble in alcohol [15]. Taking advantages of these properties, easy way to tune particles size is proposed here. In addition, weak reducing agent like ascorbic acid tends to retard the reaction. Therefore, we observed few minutes delay in nucleation process.

Scheme. 1 Possible mechanisms of bismuth nanoparticles formation in the presence of additives

500nm

500nm

500nm

Fig. 1. FE-SEM images of bismuth nanoparticle synthesized in the presence of (a) 300 μl of ascorbic acid, (b) 300 μl of AOT, and (c) ethanol: water in a ratio of 8:2.

As-prepared bismuth nanoparticles were examined using Field-Emission Scanning Electron Microscope as shown in Fig. 1. Most of particles are spherical-like shape, although some irregular shapes are occasionally seen. The pH of growth solution were also investigated to see the pH-dependent effect which have reported recently [12].

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In our method, we did not observe the difference in shape when pH of growth solution is in the range of 8-11. Fig. 2 shows size distribution of bismuth nanoparticles prepared by different additives.

Fig. 2. Size distribution and standard deviation of bismuth nanoparticle synthesized in the presence of (a) 300 μl of ascorbic acid, (b) 300 μl of AOT, and (c) ethanol: water in a ratio of 8:2.

To further investigate hydrodynamic diameter of nanoparticles at various concentration of different chemical additives, we tracked the particle motions with nanoparticle tracking analysis system (NTA 3.0). Each sample was dissolved in water with 2% tween80 to make them water-soluble. We found that increasing concentration of ascorbic acid in the growth solution leading to a bigger nanocrystal forming, Fig. 3a. However, ascorbic acid has not potentially changed the diameter of bismuth nanoparticles. It obviously quenched the crystal formation by delaying the nucleation time and reduced the product. As shown in Table 1, 15.3 mg of bismuth nanopowder can be collected from the reaction in the presence of 100 μl of ascorbic acid. By increasing concentration almost 5 times of ascorbic acid, only 10.1 mg can be found which mean more than 30% loss. It is worth noting that ascorbic acid is known for weak reducing agent which widely uses in gold nanorods formation. Ascorbic acid slowly reduces gold ion to become gold crystal, therefore, rod shape is formed [16]. Here, we found that ascorbic acid alone cannot reduce bismuth ion to bismuth crystal. Thus, strong reducing agent NaBH4 is needed. Without ascorbic acid addition, more irregular shapes can be observed. An interesting effect of co-surfactant has proved by adding different amount of AOT. Hydrodynamic diameters of bismuth nanoparticles decrease from 195.3 nm to 107.4 nm while concentration of AOT increases almost 5 times, Fig. 3b. With a carefully surfactant removal, obtained bismuth nanopowder synthesized by adding 300 μl of AOT weighs 138.53% comparing with adding 100 μl of AOT. For 400 and 500 μl of AOT, amount of collected nanopowder is similar. The finding shows that adding AOT not only changes size of nanoparticles but also increases synthesized product. On the other hand, alcohol increases size of nanoparticles from 98.5nm to 162.9 nm when the ratio of ethanol and water increases, Fig. 3c. At higher concentration of ethanol, smaller amount of nanopowder are observed. Although ethanol demonstrates a great potential to tune size of bismuth nanoparticles, amount of collected nanopowder can be 21.9% by weight loss.

Fig. 3. Hydrodynamic diameter of bismuth nanoparticle synthesized in the presence of (a) 300 μl of ascorbic acid, (b) 300 μl of AOT, and (c) ethanol: water in a ratio of 8:2.

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Table 1. Mass volume of prepared nanoparticles is additive material. additive material

average weight (mg)

ascorbic acid 100 μl

15.3

ascorbic acid 200 μl

14.2

ascorbic acid 300 μl

14.1

ascorbic acid 400 μl

11.1

ascorbic acid 500 μl

10.1

AOT 100 μl

10.9

AOT 200 μl

11.3

AOT 300 μl

15.1

AOT 400 μl

15.1

AOT 500 μl

15.3

DI 10 ml + Ethanol 0 ml

13.2

DI 8 ml + Ethanol 2 ml

13.1

DI 5 ml + Ethanol 5 ml

11.3

DI 2 ml + Ethanol 8 ml

11.1

DI 0 ml + Ethanol 10 ml

10.3

Fig. 4. XRD patterns of bismuth nanoparticles containing ascorbic acid 100 μl.

In addition, XRD measurements were used to determine the crystalline phase of the as-prepared bismuth nanopowders. XRD patterns of samples containing ascorbic acid 100 μl are shown in Fig. 4. All of the reflections can be readily indexed to the pure rhombohedral phase of Bi (JCPDS No. 004-1246). 4. Conclusion Additive chemicals show ability in tuning size of bismuth nanoparticles and also affect the amount of prepared nanopowder. Higher concentration of weak reducing agent like ascorbic acid yields smaller in amount of product, similar to ethanol. Dioctyl sulfosuccinate sodium salt (AOT), oppositely, can reduce size of bismuth nanoparticles and increase weight of synthesis powder. This study provides a room-temperature synthesis method and will be useful for the development of industrial-scale production. Acknowledgements This study is supported by National Research Council of Thailand.

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References [1] K. mandal, Structural and optical properties of single crystalline bismuth nanoparticles in polymer, Phys. Conf. Ser. 2013.22:654-659. [2] S. Dadashi , H. Delavari , R. Poursalehi, Optical Properties and Colloidal Stability Mechanism of Bismuth Nanoparticles Prepared by QSwitched Nd:Yag Laser Ablation in Liquid, Procedia Materials Science ,11, ( 2015 ),679 – 683. [3] Sarah Ashour Hamood, and Ziad Tarik Aldahan, Bismuth Nanoparticle as Anti-Breast Cancer Agent Synthesis and Investigation, Biological and Chemical Sciences, (2016), 809. [4] Naraavula Suresh Kumar, Katrapally Vijaya Kumar, Synthesis and Structural Properties of Bismuth Doped Cobalt Nanoferrites Prepared by Sol-Gel Combustion Method, Science and Engineering, 5, (2015), 140-151. [5] Dechong Ma, Jingzhe Zhao, Yan Zhaoa, Xinli Haoa, Linzhi Li , Li Zhang, Yan Lu, Chengzhong Yu, Synthesis of bismuth nanoparticles and self-assembled nanobelts by a simpleaqueous route in basic solution, Physicochemical and Engineering Aspects. 395, (2012), 276-283. [6] Rene Hernandez-Delgadillo, Appala Raju Badireddy, Valentin Zaragoza-Magana, Rosa Isela Sanchez-Najera, Shankararaman Chellam, Claudio Cabral-Romero. Effect of Lipophilic Bismuth Nanoparticles on Erythrocytes, Nanomaterials (2015). [7] Rabin, O., Manuel, P.J., Grimm J., Wojtkiewicz, G., and Weissleder, R., An X-ray computed tomography imaging agent based on longcirculating bismuth sulphide nanoparticles, Nat. Mater., 5 (2006), 118-122. [8] Miquel Cadevall, Josep Ros, Arben Merkoci, Bismuth nanoparticles integration into heavy metal electrochemical stripping sensor, Electroohoresis, 36 (2015), 1872-1879. [9] Haifeng Yang, Junfang Li, Xiaojing Lu, Guangcheng Xi, Yan Yan, Reliable synthesis of bismuth nanoparticles for heavy metal detection, Materials Research Bulletin, 48, (2013), 4718-4722 [10] J. Chen, L.M.Wu, L. Chen, Synthesis and characterizations of bismuth nanofilms and nanorhombuses by the structure-controlling solventless method, Inorg. Chem, 46, (2007), 586–591. [11] Y.D. Li, J.W. Wang, Z.X. Deng, Y.Y. Wu, X.M. Sun, D.P. Yu, P.D. Yang, Bismuth nanotubes: a rational low-temperature synthetic route, J. Am. Chem. Soc. 123, (2001), 9904–9905. [12] Anna L. Brown Andrea M. Goforth, pH-Dependent Synthesis and Stability of Aqueous, Elemental Bismuth Glyconanoparticle Colloids: Potentially Biocompatible X-ray Contrast Agents, Chem. Mater. 24, (2012), 1599-1605. [13] E.E. Foos, R.M. Stroud, A.D. Berry, A.W. Snow, J.P. Armistead, Synthesis of nanocrystalline bismuth in reverse micelles, J. Am. Chem. Soc. 122, (2000), 7114-7115. [14] Kakehashi R, Shizuma M, Yamamura S, Takeda T, Mixed micelles containing sodium oleate: the effect of the chain length and the polar head group, Colloid Interface Sci. (2004), 253-279. [15] R. Zana, S. Yiv, C Strazielle, P Lianos, Effect of alcohol on the properties of micellar systems: I. Critical micellization concentration, micelle molecular weight and ionization degree, and solubility of alcohols in micellar solutions, Colloid Interface Sci. (1981), 208-223. [16] A. Gole and C.J. Murphy, Seed-Mediated Synthesis of Gold Nanorods:  Role of the Size and Nature of the Seed, Chem. Mater. 16, (2004), 3633–3640.