The effect of process parameters on the size of ZnO nanoparticles synthesized via the sol–gel technique

• Published in: Journal of alloys and compounds Vol. 550; pp. 63 - 70
• Main Authors: Ba-Abbad, Muneer M., Kadhum, Abdul Amir H., Bakar Mohamad, Abu, Takriff, Mohd S., Sopian, Kamaruzzaman
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15-02-2013; Elsevier
• Subjects: Agglomeration; Chemical synthesis methods; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of nanofabrication; Nanoparticle size; Nanoparticles; Optimal pH; Optimization; Particle size; Physics; Process parameters; Sol–gel method; Surface charge; Zinc oxide; ZnO nanoparticles; ZnO nanoparticles; Nanoparticle size; Sol–gel method; Optimal pH; Differential scanning calorimetry; Particle size; Diffuse reflection; Sol―gel method; Thermogravimetry; Calcination; Nanoparticles; Hexagonal lattices; Energy gap; Wurtzite structure; Zinc oxide; Spherical particle; Fourier-transformed infrared spectrometry; Sol-gel process; Nanomaterial synthesis
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2012.09.076

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► ZnO nanoparticle was synthesized by the sol gel method without capping agents. ► Effects of process parameters on size of ZnO nanoparticle was investigated. ► The pH and calcination temperatures indicates more effecting on band gap was observed. ► The optimum condition for mimimal size of 1:2 ratio, pH of 2.0±0.2 and calcined at 400°C were found.
This article describes the controlled size of ZnO nanoparticles when they are synthesized using the sol–gel method without the involvement of a capping agent. The effects of process parameters such as the molar ratio, pH of reactants and calcination temperatures on the size of the synthesized ZnO nanoparticles were investigated. The hexagonal wurtzite phase structure of ZnO nanoparticles was obtained in the form of spherical shapes for all samples. It was found that the ZnO nanoparticles were small in size and experienced reduced agglomeration at a 1:2 molar ratio of the starting material and pH of 2.0±0.2. The results showed that the ZnO nanoparticles had increased in size and experienced a larger agglomeration when the ratio and pH were at higher or lower than the optimal condition. The morphological observations showed increase in particle size when the calcination temperature was increased. The functional group for the ZnO nanoparticle showed a peak in the range of 494–500cm−1. The optical properties of the ZnO nanoparticles with the best band gap of 3.19eV were also evaluated under the optimal experimental conditions. The surface charge of the ZnO nanoparticles did not change, which indicated that there was no relationship between surface charge and particle size for the same type of catalyst.