- Open Access
Copper(II) oxide nanocatalyst preparation and characterization: green chemistry route
© The Author(s) 2018
- Received: 28 June 2018
- Accepted: 9 August 2018
- Published: 3 September 2018
Green synthesis as a technique of preparation of metal/metal oxide nanomaterials is becoming an important and competitive method of preparation replacing the conventional method of preparation. Among metal oxides, nanocatalyst copper(II) oxide is considered as a very important and potent catalyst/photocatalyst with a very wide range of applications.
In this work, copper(II) oxide nanoparticles were prepared with the assist of aqueous spinach extract from copper metal powder. Spinach extract catalyzes the formation of copper oxide nanoparticles with manipulation of chlorophyll that exists in the extract. The produced copper(II) oxide nanoparticles were characterized using scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD).
It was proved that spinach extract catalyzes the preparation of copper(II) oxide nanocatalyst. It was elucidated from the characterization technique that the produced nanoparticles are pure copper oxide with particle size range of 60–100 nm.
- Copper(II) oxide
- Green chemistry
Recently, green chemistry routes of preparation of different metal/metal oxide nanomaterials have been attracting increasing attention due to their advantages being operating under mild conditions, environmentally safe, and assist in manipulating the reaction condition toward the production of desired engineered nanomaterials. These green synthesis routes could be achieved by using microbial microorganism, plant-related materials, and plant extract. As it is well known, nanomaterials are effectively existed in the scientific research market due to their marvelous wide range of applications as well as their outstanding optical, chemical, and physical properties which affect to a great extent their activity. Preparation of metal oxide nanoparticles has been extensively investigated using conventional methods as sonochemical method (Chen and Mao 2007; Xu et al. 2013), hydrothermal/solvothermal synthesis (Khan et al. 2011), sol-gel method (Macwan et al. 2011), combustion (Patil et al. 1997; Patil et al. 2002), chemical precipitation (Rakhshani 1986), and metal reduction (Dang et al. 2011; Phoka et al. 2009). Also, green synthesis methods of preparation of metal oxides have been investigated extensively (Parsons et al. 2009; Klaus et al. 1999; Phumying et al. 2013; Munshi et al. n.d.). Green chemistry synthesis involves two distinguished principle roles which served as a reaction medium (could be stabilizers or capping agents) and environmentally and biologically safe reducing agents (could help in medical and biological applications). Among metal oxide nanomaterials, copper oxide represents a very important and potent candidate in a wide range of applications as magnetic storage media (Li et al. 2004), sensors (Shishiyanu et al. 2006; Kim et al. 2008), catalytic applications (de Jongh et al. 1999; Zhang et al. 2014), and many other fields of application. Cu2O is considered as a p-type semiconductor with a narrow bandgap of 1.4–1.9 eV (Grozdanov 1994), so it has a potent role in photoconductive and photothermal applications (Rakhshani 1986). In this work, CuO preparation—in a green chemistry method with the assistance of spinach extract—was studied. The obtained CuO nanoparticles were characterized using scanning electron microscopy, energy dispersive X-ray, and X-ray diffraction.
Copper powder (Ranbaxy Chemicals, > 5 μm) has been used without any preheated producer or any further purification, and de-ionized water has been prepared in the laboratory. For the synthesis of nanomaterials, a closed cylindrical Teflon-lined stainless steel chamber of 100 ml capacity (autoclave, Latech Scientific Supply Pte. Ltd. Company) was used.
The structural properties of ZnO nanoparticles were characterized using scanning electron microscopy (SEM) (NOVA NANOSEM-600) coupled with energy dispersive X-ray spectrometer (EDX). The powders were characterized by X-ray diffraction (XRD) using Cu Kα radiation (λ = 0.15141 nm) in the 2θ range from 25 to 65° with 0.02°/min performed in King Abdulaziz University labs.
An aqueous solution of fresh spinach extract in deionized (DI) water (Munshi et al. n.d.) 80 ml together with 0.2 g copper metal (powder) was placed in a stainless-steel Teflon-lined metallic autoclave of 100 ml capacity and sealed under ambient conditions. A blank sample with copper metal aqueous solution free from spinach extract was processed at the same conditions. The autoclaved reaction mixture is heated to 180 °C (2 °C/min) in a preheated furnace and left for 72 h under the same conditions. After being cooled, the produced powder was centrifuged, washed, and vacuum dried.
Scanning Electron microscopy
Energy-dispersive X-ray spectroscopy
X-ray diffraction spectroscopy
The particle size of the sample was calculated using the above formula, and the small average grain size of copper oxide nanoparticles was 0.58 nm.
From SEM, it was obvious that CuO nanoparticles appear as irregular spherical particles, with predominant tetrahedron structure with dimensions ranging from 60 to 100 nm.
Chlorophyll as the main constituent of any green plant represents a potent photocatalyst to initiate and catalyze the preparation of metal oxide nanoparticles under milder conditions than that of the conventional method of preparation. Herein, it was concluded that chlorophyll that exists in spinach aqueous catalyzed the preparation of CuO NPs in a process simulating the way of action of chlorophyll in the photosynthesis process. The produced CuO NPs were found to have a particle size ranging from 60 to 100 nm.
The authors acknowledge with thanks the KASCT for the technical and financial support.
This work was funded by King Abdulaziz for science and technology (KASCT) under Grant no. 177-34.
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- Chen X, Mao SS (2007) Titanium dioxide nanomaterials: synthesis, properties, modifications, and applications. Chem Rev 107(7):2891–2959View ArticleGoogle Scholar
- Cullity, B. D. Elements of X-ray diffraction. 2001Google 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(1):015009ADSView ArticleGoogle Scholar
- de Jongh PE, Vanmaekelbergh D, Kelly JJ (1999) Cu 2 O: a catalyst for the photochemical decomposition of water? Chem Commun (12):1069–1070. https://doi.org/10.1039/A901232J
- Grozdanov I (1994) Electroless chemical deposition technique for Cu2O thin films. Mater Lett 19(5–6):281–285View ArticleGoogle Scholar
- Khan SB, Faisal M, Rahman MM, Jamal A (2011) Exploration of CeO2 nanoparticles as a chemi-sensor and photo-catalyst for environmental applications. Sci Total Environ 409(15):2987–2992ADSView ArticleGoogle Scholar
- Kim Y-S, Hwang I-S, Kim S-J, Lee C-Y, Lee J-H (2008) CuO nanowire gas sensors for air quality control in automotive cabin. Sensors Actuators B Chem 135(1):298–303View ArticleGoogle Scholar
- Klaus T, Joerger R, Olsson E, Granqvist C-G (1999) Silver-based crystalline nanoparticles, microbially fabricated. Proc Natl Acad Sci 96(24):13611–13614ADSView ArticleGoogle Scholar
- Li X, Gao H, Murphy CJ, Gou L (2004) Nanoindentation of Cu2O nanocubes. Nano Lett 4(10):1903–1907ADSView ArticleGoogle Scholar
- Macwan D, Dave PN, Chaturvedi S (2011) A review on nano-TiO2 sol–gel type syntheses and its applications. J Mater Sci 46(11):3669–3686ADSView ArticleGoogle Scholar
- Munshi GH, Ibrahim AM, Al-Harbi LM (2018) Inspired preparation of zinc oxide nanocatalyst and the photocatalytic activity in the treatment of methyl orange dye and PARAQUAT herbicide. Int J Photoenergy 2018:7. Article ID 5094741. https://doi.org/10.1155/2018/5094741 View ArticleGoogle Scholar
- Parsons, J. G.; Peralta-Videa, J. R.; Dokken, K. M.; Gardea-Torresdey, J. L. Biological and biomaterials-assisted synthesis of precious metal nanoparticles. Nanotechnologies for the Life Sciences 2009Google Scholar
- Patil KC, Aruna ST, Ekambaram S (1997) Combustion synthesis. Curr Opinion Solid State Mater Sci 2(2):158–165ADSView ArticleGoogle Scholar
- Patil KC, Aruna ST, Mimani T (2002) Combustion synthesis: an update. Curr Opinion Solid State Mater Sci 6(6):507–512ADSView ArticleGoogle Scholar
- Phoka S, Laokul P, Swatsitang E, Promarak V, Seraphin S, Maensiri S (2009) Synthesis, structural and optical properties of CeO2 nanoparticles synthesized by a simple polyvinyl pyrrolidone (PVP) solution route. Mater Chem Phys 115(1):423–428View ArticleGoogle Scholar
- Phumying S, Labuayai S, Thomas C, Amornkitbamrung V, Swatsitang E, Maensiri S (2013) Aloe vera plant-extracted solution hydrothermal synthesis and magnetic properties of magnetite (Fe3O4) nanoparticles. Applied Physics A 111(4):1187–1193View ArticleGoogle Scholar
- Rakhshani A (1986) Preparation, characteristics and photovoltaic properties of cuprous oxide—a review. Solid State Electron 29(1):7–17ADSView ArticleGoogle Scholar
- Shishiyanu ST, Shishiyanu TS, Lupan OI (2006) Novel NO2 gas sensor based on cuprous oxide thin films. Sensors Actuators B Chem 113(1):468–476View ArticleGoogle Scholar
- Xu H, Zeiger BW, Suslick KS (2013) Sonochemical synthesis of nanomaterials. Chem Soc Rev 42(7):2555–2567View ArticleGoogle Scholar
- Zhang W, Guo F, Wang F, Zhao N, Liu L, Li J, Wang Z (2014) Synthesis of quinazolines via CuO nanoparticles catalyzed aerobic oxidative coupling of aromatic alcohols and amidines. Organic & Biomolecular Chemistry 12(30):5752–5756View ArticleGoogle Scholar