Optical properties of ZnO/BaCO3 nanocomposites in UV and visible regions
© Zak et al.; licensee Springer. 2014
Received: 2 June 2014
Accepted: 7 August 2014
Published: 18 August 2014
Pure zinc oxide and zinc oxide/barium carbonate nanoparticles (ZnO-NPs and ZB-NPs) were synthesized by the sol–gel method. The prepared powders were characterized by X-ray diffraction (XRD), ultraviolet–visible (UV–Vis), Auger spectroscopy, and transmission electron microscopy (TEM). The XRD result showed that the ZnO and BaCO3 nanocrystals grow independently. The Auger spectroscopy proved the existence of carbon in the composites besides the Zn, Ba, and O elements. The UV–Vis spectroscopy results showed that the absorption edge of ZnO nanoparticles is redshifted by adding barium carbonate. In addition, the optical parameters including the refractive index and permittivity of the prepared samples were calculated using the UV–Vis spectra.
81.05.Dz; 78.40.Tv; 42.70.-a.
Nanotechnology has the potential to create many new devices with a wide range of applications in the fields of medicine, electronics, and energy production. The increased surface area-to-volume ratios and quantum size effects are the properties that make these materials potential candidates for device applications. These properties can control optical properties such as absorption, fluorescence, and light scattering. Zinc oxide (ZnO) is one of the famous metal oxide semiconductors with a wide bandgap (3.36 eV) and large excitation binding energy. These special characteristics make it suitable to use in many applications, such as cancer treatments, optical coating, solar cells, and gas sensors. In fact, doping, morphology, and crystallite size play an important role on the optical and electrical properties of ZnO nanostructures, which can be controlled by methods of the nanostructure growth. Therefore, many methods have been created to prepare ZnO nanostructures including sol–gel, precipitation, combustion, microwave, solvothermal, spray pyrolysis, hydrothermal[13, 14], ultrasonic, and chemical vapor deposition (CVD)[16, 17]. As mentioned above, the doping of ZnO with selective elements offers an effective method to enhance and control its electrical and optical properties. The effects of several elements on the optical and electrical properties of ZnO material have been investigated. For example, Au2+, Ce3+, Eu3+, In3+, and Mg2+[22, 23] have been used in order to control the optical properties; Mn2+, Cr2+, Co2+, Ni2+, Fe3+, Cu2+, and V5+ have been used to enhance the magnetic properties; and Li1+ and Na1+ have been used to obtain a p-type form of ZnO.
In the present research, a modified sol–gel route was used to prepare ZnO/BaCO3 nanoparticles (x = 0, ZnO-NPs; x = 0.1, ZB10-NPs; x = 0.2, ZB20-NPs) using gelatin as a polymerization agent. The gelatin was used as a terminator for growing the ZnO/BaCO3-NPs because it expands during the calcination process and the particles cannot come together easily. The crystallite size and crystallinity of the resulting ZnO/BaCO3-NPs were investigated.
In order to synthesize zinc oxide/barium carbonate nanoparticles (ZB-NPs), analytical-grade zinc nitrate hexahydrate (Zn(NO3)2 · 6H2O, Sigma-Aldrich, St. Louis, MO, USA), barium nitrate (Ba(NO3)2, Sigma-Aldrich), and gelatin [(NHCOCH-R1) n , R1 = amino acid, type b, Sigma-Aldrich] were used as starting materials and distilled water as solvent. To prepare 10 g of the final product (ZB-NPs), the appropriate amounts of zinc and barium nitrate were dissolved in 50 ml of distilled water. The amounts of the precursor materials were calculated according to the (1 - x)ZnO/(x)BaCO3 formula, where x = 0, 0.1, and 0.2. On the other hand, 8 g of gelatin was dissolved in 300 ml of distilled water, and the solution was stirred at 60°C to obtain a clear gelatin solution. Finally, the Zn2+/Ba2+ solution was added to the gelatin solution. The container was then moved into an oilbath; meanwhile, the temperature of the oilbath was kept at 80°C while being continuously stirred to achieve a viscose, clear, and honey-like gel. For the calcination process, the gel was slightly rubbed on the inner walls of a crucible and then placed into the furnace. The temperature of the furnace was fixed at 650°C for 2 h, with a heating rate of 2°C/min.
The phase evolutions and structure of the prepared pure zinc oxide nanoparticles (ZnO-NPs) and ZB-NPs were investigated by X-ray diffraction (XRD; Philips X'pert, Cu Kα, Philips, Amsterdam, the Netherlands). The transmission electron microscopy (TEM) observations were carried out on a Hitachi H-7100 electron microscope (Hitachi Ltd., Chiyoda-ku, Japan) to examine the shape and particle size of the nanoparticles and field emission Auger electron spectroscopy (AES; JAMP-9500 F, JEOL Ltd., Akishima-shi, Japan) for elemental analysis. The ultraviolet–visible (UV–Vis) spectra were recorded by a PerkinElmer Lambda 25 UV–Vis spectrophotometer (PerkinElmer, Waltham, MA, USA).
Results and discussion
UV–Vis diffuse reflectance spectra and bandgap
The derivative method has been found as an easy and accurate method to calculate the optical bandgap compared to the Kubelka-Munk method. In this method, the direct bandgap can be estimated from the maximum of the first derivative of the absorbance data plotted versus energy or from the intersection of the second derivative with energy axis.
Method of optical constant calculations
Auger spectroscopy of ZnO/BaCO3 nanocomposites
ZnO and ZnO/BaCO3 nanoparticles were synthesized by the sol–gel method. XRD was used to study the crystallite sizes and structures. The crystallite sizes of the prepared BaCO3 and ZnO nanoparticles were obtained to be 12 ± 2 and 21 ± 2 nm, respectively, for ZB20-NPs. The average particle size of the prepared ZB20-NPs was obtained to be 30 nm, which supports the XRD results. The optical properties of the prepared samples were studied using UV–Vis spectroscopy. The analyzed results showed that the resonance frequency of the refractive index and permittivity is redshifted by BaCO3 concentration increases. The bandgaps of the pure ZnO, ZB10, and ZB20 nanoparticles were estimated to be 3.3, 3.28, and 3.24, respectively.
A. Khorsand Zak thanks Universiti Teknologi Malaysia for the postdoctoral fellowship. This work was funded by Universiti Teknologi Malaysia.
- Buot FA: Mesoscopic physics and nanoelectronics: nanoscience and nanotechnology. Phys Rep 1993, 234: 73–174. 10.1016/0370-1573(93)90097-WView ArticleGoogle Scholar
- Huang S, Schlichthörl G, Nozik A, Grätzel M, Frank A: Charge recombination in dye-sensitized nanocrystalline TiO2 solar cells. J Phys Chem B 1997, 101: 2576–2582. 10.1021/jp962377qView ArticleGoogle Scholar
- Lu L, Li R, Fan K, Peng T: Effects of annealing conditions on the photoelectrochemical properties of dye-sensitized solar cells made with ZnO nanoparticles. Sol Energy 2010, 84: 844–853. 10.1016/j.solener.2010.02.010View ArticleGoogle Scholar
- Zhang H, Chen B, Jiang H, Wang C, Wang H, Wang X: A strategy for ZnO nanorod mediated multi-mode cancer treatment. Biomaterials 2011, 32: 1906–1914. 10.1016/j.biomaterials.2010.11.027View ArticleGoogle Scholar
- Prepelita P, Medianu R, Sbarcea B, Garoi F, Filipescu M: The influence of using different substrates on the structural and optical characteristics of ZnO thin films. Appl Surf Sci 2010, 256: 1807–1811. 10.1016/j.apsusc.2009.10.011View ArticleGoogle Scholar
- Lee J-H: Gas sensors using hierarchical and hollow oxide nanostructures: overview. Sens Actuators B 2009, 140: 319–336. 10.1016/j.snb.2009.04.026View ArticleGoogle Scholar
- Zak AK, Majid W, Darroudi M, Yousefi R: Synthesis and characterization of ZnO nanoparticles prepared in gelatin media. Mater Lett 2011, 65: 70–73. 10.1016/j.matlet.2010.09.029View ArticleGoogle Scholar
- Song R, Liu Y, He L: Synthesis and characterization of mercaptoacetic acid-modified ZnO nanoparticles. Solid State Sci 2008, 10: 1563–1567. 10.1016/j.solidstatesciences.2008.02.006View ArticleGoogle Scholar
- Zak AK, Abrishami ME, Majid W, Yousefi R, Hosseini S: Effects of annealing temperature on some structural and optical properties of ZnO nanoparticles prepared by a modified sol–gel combustion method. Ceram Int 2011, 37: 393–398. 10.1016/j.ceramint.2010.08.017View ArticleGoogle Scholar
- Thongtem T, Phuruangrat A, Thongtem S: Characterization of nanostructured ZnO produced by microwave irradiation. Ceram Int 2010, 36: 257–262. 10.1016/j.ceramint.2009.07.027View ArticleGoogle Scholar
- Razali R, Zak AK, Majid WHA, Darroudi M: Solvothermal synthesis of microsphere ZnO nanostructures in DEA media. Ceram Int 2011, 37: 3657–3663. 10.1016/j.ceramint.2011.06.026View ArticleGoogle Scholar
- Milošević O, Jordović B, Uskoković D: Preparation of fine spherical ZnO powders by an ultrasonic spray pyrolysis method. Mater Lett 1994, 19: 165–170. 10.1016/0167-577X(94)90063-9View ArticleGoogle Scholar
- Ismail A, El-Midany A, Abdel-Aal E, El-Shall H: Application of statistical design to optimize the preparation of ZnO nanoparticles via hydrothermal technique. Mater Lett 2005, 59: 1924–1928. 10.1016/j.matlet.2005.02.027View ArticleGoogle Scholar
- Sun T, Hao H, Hao W-t, Yi S-m, Li X-p, Li J-r: Preparation and antibacterial properties of titanium-doped ZnO from different zinc salts. Nanoscale Res Lett 2014, 9: 98. 10.1186/1556-276X-9-98View ArticleGoogle Scholar
- Khorsand Zak A, Majid WH, Wang HZ, Yousefi R, Moradi Golsheikh A, Ren ZF: Sonochemical synthesis of hierarchical ZnO nanostructures. Ultrason Sonochem 2013, 20: 395–400. 10.1016/j.ultsonch.2012.07.001View ArticleGoogle Scholar
- Yousefi R, Zak AK, Mahmoudian MR: Growth and characterization of Cl-doped ZnO hexagonal nanodisks. J Solid State Chem 2011, 184: 2678–2682. 10.1016/j.jssc.2011.08.001View ArticleGoogle Scholar
- Ahmad N, Rusli N, Mahmood M, Yasui K, Hashim A: Seed/catalyst-free growth of zinc oxide nanostructures on multilayer graphene by thermal evaporation. Nanoscale Res Lett 2014, 9: 83. 10.1186/1556-276X-9-83View ArticleGoogle Scholar
- Hongsith N, Viriyaworasakul C, Mangkorntong P, Mangkorntong N, Choopun S: Ethanol sensor based on ZnO and Au-doped ZnO nanowires. Ceram Int 2008, 34: 823–826. 10.1016/j.ceramint.2007.09.099View ArticleGoogle Scholar
- George A, Sharma SK, Chawla S, Malik M, Qureshi M: Detailed of X-ray diffraction and photoluminescence studies of Ce doped ZnO nanocrystals. J Alloys Compd 2011, 509: 5942–5946. 10.1016/j.jallcom.2011.03.017View ArticleGoogle Scholar
- Yu Y, Chen D, Huang P, Lin H, Wang Y: Structure and luminescence of Eu3+ doped glass ceramics embedding ZnO quantum dots. Ceram Int 2010, 36: 1091–1094. 10.1016/j.ceramint.2009.12.007View ArticleGoogle Scholar
- Yousefi R, Muhamad MR, Zak AK: Investigation of indium oxide as a self-catalyst in ZnO/ZnInO heterostructure nanowires growth. Thin Solid Films 2010, 518: 5971–5977. 10.1016/j.tsf.2010.05.111View ArticleGoogle Scholar
- Khorsand Zak A, Yousefi R, Majid WHA, Muhamad MR: Facile synthesis and X-ray peak broadening studies of Zn1-x Mg x O nanoparticles. Ceram Int 2012, 38: 2059–2064. 10.1016/j.ceramint.2011.10.042View ArticleGoogle Scholar
- Yousefi R, Zak AK, Jamali-Sheini F: Growth, X-ray peak broadening studies, and optical properties of Mg-doped ZnO nanoparticles. Mater Sci Semicond Process 2013, 16: 771–777. 10.1016/j.mssp.2012.12.025View ArticleGoogle Scholar
- Jayakumar O, Gopalakrishnan I, Sudakar C, Kadam R, Kulshreshtha S: Significant enhancement of room temperature ferromagnetism in surfactant coated polycrystalline Mn doped ZnO particles. J Alloys Compd 2007, 438: 258–262. 10.1016/j.jallcom.2006.08.030View ArticleGoogle Scholar
- Li Y, Li Y, Zhu M, Yang T, Huang J, Jin H, Hu Y: Structure and magnetic properties of Cr-doped ZnO nanoparticles prepared under high magnetic field. Solid State Commun 2010, 150: 751–754. 10.1016/j.ssc.2010.01.027View ArticleGoogle Scholar
- Wesselinowa J, Apostolov A: A possibility to obtain room temperature ferromagnetism by transition metal doping of ZnO nanoparticles. J Appl Phys 2010, 107: 053917–053917–053915.View ArticleGoogle Scholar
- Yousefi R, Zak AK, Jamali-Sheini F: The effect of group-I elements on the structural and optical properties of ZnO nanoparticles. Ceram Int 2013, 39: 1371–1377. 10.1016/j.ceramint.2012.07.076View ArticleGoogle Scholar
- Khorsand Zak A, Abd Majid WH, Mahmoudian MR, Darroudi M, Yousefi R: Starch-stabilized synthesis of ZnO nanopowders at low temperature and optical properties study. Adv Powder Technol 2013, 24: 618–624. 10.1016/j.apt.2012.11.008View ArticleGoogle Scholar
- Farag AAM, Yahia IS: Structural, absorption and optical dispersion characteristics of rhodamine B thin films prepared by drop casting technique. Opt Commun 2010, 283: 4310–4317. 10.1016/j.optcom.2010.06.081View ArticleGoogle Scholar
- Wang D-W, Zhao S-L, Xu Z, Kong C, Gong W: The improvement of near-ultraviolet electroluminescence of ZnO nanorods/MEH-PPV heterostructure by using a ZnS buffer layer. Org Electron 2011, 12: 92–97. 10.1016/j.orgel.2010.09.018View ArticleGoogle Scholar
- Khorsand Zak A, Razali R, Abd Majid WH, Darroudi M: Synthesis and characterization of a narrow size distribution of zinc oxide nanoparticles. Int J Nanomedicine 2011, 6: 1399–1403.View ArticleGoogle Scholar
- Zak AK, Majid WHA: Effect of solvent on structure and optical properties of PZT nanoparticles prepared by sol–gel method, in infrared region. Ceram Int 2011, 37: 753–758. 10.1016/j.ceramint.2010.10.020View ArticleGoogle Scholar
- Deng X, Sun J, Yu S, Xi J, Zhu W, Qiu X: Steam reforming of ethanol for hydrogen production over NiO/ZnO/ZrO2 catalysts. Int J Hydrog Energy 2008, 33: 1008–1013.Google Scholar
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