- Nano Express
- Open Access
Synthesis and Characterization of Pure Copper Nanostructures Using Wood Inherent Architecture as a Natural Template
© The Author(s). 2018
- Received: 4 January 2018
- Accepted: 17 April 2018
- Published: 24 April 2018
The inherent sophisticated structure of wood inspires researchers to use it as a natural template for synthesizing functional nanoparticles. In this study, pure copper nanoparticles were synthesized using poplar wood as a natural inexpensive and renewable template. The crystal structure and morphologies of the copper nanoparticles were characterized by X-ray diffraction and field emission scanning electron microscopy. The optical properties, antibacterial properties, and stability of the hybrid wood materials were also tested. Due to the hierarchical and anisotropic structure and electron-rich components of wood, pure copper nanoparticles with high stability were synthesized with fcc structure and uniform sizes and then assembled into corncob-like copper deposits along the wood cell lumina. The products of nanoparticles depended strongly on the initial OH− concentration. With an increase in OH− concentration, Cu2O gradually decreased and Cu remained. Due to the restrictions inherent in wood structure, the derived Cu nanoparticles showed similar grain size in spite of increased Cu2+ concentration. This combination of Cu nanostructures and wood exhibited remarkable optical and antibacterial properties.
- Copper nanoparticles
- Wood template
- Hierarchical structure
Metal nanoparticles have garnered wide attention in the scientific community thanks to their exceptional physical and chemical properties . Silver and gold have attracted particularly great interest given their unique plasmon resonance and high stability. However, the high cost of silver and gold limits their wide industrial application . Because copper is much cheaper and more abundant, copper nanoparticles (Cu NPs) may be considered a replacement for silver and gold NPs. Moreover, Cu-based NPs are gaining importance thanks to their catalytic, optical, antibacterial, and electrical conducting properties [3–5]. To fully utilize these properties, the size, purity, and shapes of copper must be well controlled. Therefore, various attempts have been proposed to synthesize NPs with a controlled shape and a specific size distribution, such as solution reduction, thermal decomposition, metal vapor synthesis, radiation methods, microemulsion techniques, mechanical attrition, and electrodeposition [6–10]. Among these, the solution reduction approach is a feasible and exceptionally versatile method for the preparation of Cu NPs. However, it is common to find nanoparticle molecules with spherical shapes; controlled NPs synthesis with other distinct surface morphologies can be accomplished using some unique organic/inorganic templates . Nevertheless, the template consumption in the preparation process is costly, and the procedure is tedious .
Another issue in utilizing these Cu NPs is their inherent propensity for surface oxidation in air and resultant aggregation . To avoid this problem, an inert environment (e.g., nitrogen or argon) is used . Other reports have presented various approaches that attempt to address the oxidation problem; such methods are generally based on minimizing exposure of the Cu NPs to oxygen through a protective layer at the particle surface. This layer may consist of polymers , organic ligands [16, 17], carbon and graphene , or inert metal ; however, these strategies require complex processes and/or special equipment.
In addition to the unique structure of wood, its lignocellulosic nature—composed of cellulose, lignin, and hemicelluloses—has a reducing and stabilizing effect on metal NPs given the electron-rich features of hydroxyl and phenolic groups in these components . Lin [25, 26] demonstrated that Pt NPs and Ag NPs with a controlled size and shape were successfully synthesized using wood nanomaterials in aqueous systems without employing any other reductants. They attributed the formation of NPs to the reducibility of hydroxyl and phenolic groups in wood components that reduce Pt ions and Ag ions. However, the sophisticated structure of wood has been underused such that the generated Cu NPs have been susceptible to oxidation in previous studies. Hence, wood components appear to be beneficial to NP stability if the NPs are synthesized using solid wood as a template.
In this study, we reported the success of a novel Cu architecture via chemical reduction within poplar wood as the natural template. The morphologies and crystal structure of the Cu NPs were characterized, and the stability, optical properties, and antibacterial properties of the hybrid wood materials were investigated.
From the sound sapwood portions of poplar (Populus tomentosa Carr.), samples with a dimension of 50 × 50 × 5 (longitudinal) mm3 were prepared and oven-dried at 103 °C to a constant weight.
Copper (II) chloride dehydrate (CuCl2·2H2O) and sodium borohydride (NaBH4) were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Other analytical-grade chemical reactants were obtained from Beijing Chemical Reagents Co., Ltd. (Beijing, China).
Preparation of Wood/Cu Composites
Characterization of Cu Nanostructures
The X-ray diffraction (XRD) measurements of the NPs were carried out using a Bruker D8 advance diffractometer (Germany). The apparatus parameters were set as follows: Cu-Kα radiation with a graphite monochromator, voltage 40 kV, electric current 40 mA, and 2θ scan range from 5° to 90° with a scanning speed of 2°/min.
The morphologies of Cu nanostructures were examined using a field emission scanning electron microscope (FE-SEM, Hitachi SU8010, Japan) equipped with an energy dispersive X-ray spectroscope (EDS, EX-350, Horiba Scientific, Japan). The interior portions of longitudinal planes in the sample were mounted on conductive adhesives and were coated with gold sputter followed by observation using FE-SEM at a voltage of 5 kV.
Evaluation of Optical and Antibacterial Properties
The diffuse reflectance UV-VIS spectra were measured using a UV-VIS spectrophotometer (Cary-300) equipped with an integrating sphere. The scanning range was from 800 to 300 nm.
For bactericidal experiments, the hybrid wood materials were machined into round shape with diameter of 10 mm. The bacterial suspension (Escherichia coli) was applied uniformly on the surface of a nutrient agar plate before placing the samples on the plate (1 control and 2 treated samples per plate). The plates were incubated at 37 °C for 24 h, after which the average diameters of the inhibition zone surrounding the samples were measured with a ruler with up to 0.1 mm resolution.
X-ray Diffraction Analysis
The grain size of Cu NPs in group C, E, and F
Grain size (nm)
19.54 ± 1.87
18.34 ± 1.59
19.74 ± 2.41
18.93 ± 1.18
21.36 ± 3.09
20.08 ± 1.76
Optical and Antibacterial Properties
To leverage the inherent hierarchical, anisotropic architecture, and electron-rich components of wood, pure Cu NPs were derived with unique shapes and sizes through wood template methods. The Cu NPs exhibited a 3D structure along the wood cell lumina that consisted of corncob-like Cu deposits. The nanoparticle products depended strongly on the initial OH− concentration. With an increase in OH− concentration, Cu2O gradually decreased and Cu remained. As the Cu2+ concentration increased gradually, more Cu NPs were generated in the wood structure. The assembled structure of NPs invariably exhibited corncob-like Cu deposits in the wood templates. Due to the unique structure and components of wood, the oxidation and aggregation of Cu NPs could be circumvented. Additionally, this new hybrid wood material, combined with the advantages of wood and Cu nanostructures, exhibited remarkable optical and antibacterial properties.
The authors are very grateful for the support from the China Scholarship Council (CSC).
This work was supported by the Fundamental Research Funds for the Central Universities (no. 2016ZCQ01) and the National Natural Science Foundation of China (Project 51779005/E090301).
Availability of Data and Materials
The datasets generated during and/or analyzed during the current study are available from the corresponding authors on reasonable request.
YD, KW, YT, and QW conducted the experiments and gathered the data. SZ, HM, and JL conceived and supervised the work. YD analyzed the data and prepared the manuscript. All authors read and approved the final manuscript.
The authors declare that they have no competing interests.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
- Perelaer J, Smith PJ, Mager D, Soltman D, Volkman SK, Subramanian V et al (2010) Printed electronics: the challenges involved in printing devices, interconnects, and contacts based on inorganic materials. J Mater Chem 20:8446–8453View ArticleGoogle Scholar
- Tsai CY, Chang WC, Chen GL, Chung CH, Liang JX, Ma WY et al (2015) A study of the preparation and properties of antioxidative copper inks with high electrical conductivity. Nanoscale Res Lett 10:357View ArticleGoogle Scholar
- Dayakar T, Rao KV, Bikshalu K, Rajendar V, Park SH (2017) Novel synthesis and characterization of pristine Cu nanoparticles for the non-enzymatic glucose biosensor. J Mater Sci Mater Med 28:109View ArticleGoogle Scholar
- Cheirmadurai K, Biswas S, Murali R, Thanikaivelan P (2014) Green synthesis of copper nanoparticles and conducting nanobiocomposites using plant and animal sources. RSC Adv 4:19507–19511View ArticleGoogle Scholar
- Zhang HX, Siegert U, Liu R, Cai WB (2009) Facile fabrication of ultrafine copper nanoparticles in organic solvent. Nanoscale Res Lett 4:705–708View ArticleGoogle Scholar
- Kumar A, Saxena A, De A, Shankar R, Mozumdar S (2013) Facile synthesis of size-tunable copper and copper oxide nanoparticles using reverse microemulsions. RSC Adv 3:5015–5021View ArticleGoogle Scholar
- Gawande MB, Goswami A, Felpin FX, Asefa T, Huang X, Silva R et al (2016) Cu and cu-based nanoparticles: synthesis and applications in catalysis. Chem Rev 116:3722–3811View ArticleGoogle Scholar
- Ramyadevi J, Jeyasubramanian K, Marikani A, Rajakumar G, Rahuman AA (2012) Synthesis and antimicrobial activity of copper nanoparticles. Mater Lett 71:114–116View ArticleGoogle Scholar
- Nam D, Kim R, Han D, Kim J, Kwon H (2011) Effects of (NH4)2SO4 and BTA on the nanostructure of copper foam prepared by electrodeposition. Electrochim Acta 56:9397–9405View ArticleGoogle Scholar
- Salavati-Niasari M, Davar F (2009) Synthesis of copper and copper (I) oxide nanoparticles by thermal decomposition of a new precursor. Mater Lett 63:441–443View ArticleGoogle Scholar
- Zhang QL, Yang ZM, Ding BJ, Lan XZ, Guo YJ (2010) Preparation of copper nanoparticles by chemical reduction method using potassium borohydride. Trans Nonferrous Metals Soc China 20:s240–s244View ArticleGoogle Scholar
- Xu C, Nie D, Chen H, Wang Y, Liu Y (2015) Template-free synthesis of magnetic CoNi nanoparticles via a solvothermal method. Mater Lett 138:158–161View ArticleGoogle Scholar
- Magdassi S, Grouchko M, Kamyshny A (2010) Copper nanoparticles for printed electronics: routes towards achieving oxidation stability. Materials 3:4626–4638View ArticleGoogle Scholar
- Umer A, Naveed S, Ramzan N, Rafique MS (2012) Selection of a suitable method for the synthesis of copper nanoparticles. Nano 7:1230005View ArticleGoogle Scholar
- Pulkkinen P, Shan J, Leppänen K, Känsäkoski A, Laiho A, Järn M et al (2009) Poly (ethylene imine) and tetraethylenepentamine as protecting agents for metallic copper nanoparticles. ACS Appl Mater Interface 1:519–525View ArticleGoogle Scholar
- Mott D, Galkowski J, Wang L, Luo J, Zhong CJ (2007) Synthesis of size-controlled and shaped copper nanoparticles. Langmuir 23:5740–5745View ArticleGoogle Scholar
- Raza A, Javed S, Qureshi MZ, Khan MU, Khan MS (2017) Synthesis and study of catalytic application of l-methionine protected gold nanoparticles. Appl Nanosci 7:429–437View ArticleGoogle Scholar
- Luechinger NA, Athanassiou EK, Stark WJ (2008) Graphene-stabilized copper nanoparticles as an air-stable substitute for silver and gold in low-cost ink-jet printable electronics. Nanotechnol 19:445201View ArticleGoogle Scholar
- Cazayous M, Langlois C, Oikawa T, Ricolleau C, Sacuto A (2006) Cu-ag core-shell nanoparticles: a direct correlation between micro-Raman and electron microscopy. Phys Rev B 73:113402View ArticleGoogle Scholar
- Keplinger T, Cabane E, Berg JK, Segmehl JS, Bock P, Burgert I (2016) Smart hierarchical bio-based materials by formation of stimuli-responsive hydrogels inside the microporous structure of wood. Adv Mater Interface:3. https://doi.org/10.1002/admi.201600233
- Dong Y, Yan Y, Ma H, Zhang S, Li J, Xia C et al (2017) In-situ chemosynthesis of ZnO nanoparticles to endow wood with antibacterial and UV-resistance properties. J Mater Sci Technol 33:266–270View ArticleGoogle Scholar
- Trey SM, Olsson RT, Strom V, Berglund LA, Johansson M (2014) Controlled deposition of magnetic particles within the 3-D template of wood: making use of the natural hierarchical structure of wood. RSC Adv 4:35678–35685View ArticleGoogle Scholar
- Merk V, Chanana M, Gierlinger N, Hirt AM, Burgert I (2014) Hybrid wood materials with magnetic anisotropy dictated by the hierarchical cell structure. ACS Appl Mater Interface 6:9760–9767View ArticleGoogle Scholar
- Benaissi K, Johnson L, Walsh DA, Thielemans W (2010) Synthesis of platinum nanoparticles using cellulosic reducing agents. Green Chem 12:220–222View ArticleGoogle Scholar
- Lin X, Wu M, Wu D, Kuga S, Endo T, Huang Y (2011) Platinum nanoparticles using wood nanomaterials: eco-friendly synthesis, shape control and catalytic activity for p-nitrophenol reduction. Green Chem 13:283–287View ArticleGoogle Scholar
- Lin X, Wang F, Kuga S, Endo T, Wu M, Wu D et al (2014) Eco-friendly synthesis and antibacterial activity of silver nanoparticles reduced by nano-wood materials. Cellulose 21:2489–2496View ArticleGoogle Scholar
- Cave I (1997) Theory of X-ray measurement of microfibril angle in wood. Wood Sci Technol 31:225–234View ArticleGoogle Scholar
- Kou J, Saha A, Bennett-Stamper C, Varma RS (2012) Inside-out core–shell architecture: controllable fabrication of Cu2O@cu with high activity for the Sonogashira coupling reaction. Chem Commun 48:5862–5864View ArticleGoogle Scholar
- Glavee GN, Klabunde KJ, Sorensen CM, Hadjipanayis GC (1994) Borohydride reduction of nickel and copper ions in aqueous and nonaqueous media. Controllable chemistry leading to nanoscale metal and metal boride particles. Langmuir 10:4726–4730View ArticleGoogle Scholar
- Dang TMD, Le TTT, Fribourg-Blanc E, Dang MC (2011) Synthesis and optical properties of copper nanoparticles prepared by a chemical reduction method. Adv Nat Sci Nanosci Nanotechnol 2:015009View ArticleGoogle Scholar
- Liu QM, Zhou DB, Yamamoto Y, Ichino R, Okido M (2012) Preparation of Cu nanoparticles with NaBH4 by aqueous reduction method. Trans Nonferrous Met Soc China 22:117–123View ArticleGoogle Scholar
- Liu QM, Zhou DB, Yamamoto Y, Kuruda K, Okido M (2012) Effects of reaction parameters on preparation of Cu nanoparticles via aqueous solution reduction method with NaBH4.Trans Nonferrous Met Soc China 22:2991–2996Google Scholar
- Qi L, Ma J, Shen J (1997) Synthesis of copper nanoparticles in nonionic water-in-oil microemulsions. J Colloid Interface Sci 186:498–500View ArticleGoogle Scholar
- Li A, Jin Y, Muggli D, Pierce DT, Aranwela H, Marasinghe GK et al (2013) Nanoscale effects of silica particle supports on the formation and properties of TiO2 nanocatalysts. Nano 5:5854–5862Google Scholar
- Kanninen P, Johans C, Merta J, Kontturi K (2008) Influence of ligand structure on the stability and oxidation of copper nanoparticles. J Colloid Interface Sci 318:88–95View ArticleGoogle Scholar
- Gascón-Garrido P, Mainusch N, Militz H, Viöl W, Mai C (2017) Copper and aluminium deposition by cold-plasma spray on wood surfaces: effects on natural weathering behaviour. Eur J Wood Prod 75:315–324View ArticleGoogle Scholar