Alcoholic Solvent Influence on ZnO Synthesis: A Joint Experimental and Theoretical Study

Abstract

Zinc oxide nanoparticles were prepared by a solvothermal synthesis using various alcoholic reaction solvents including ethanol, 1-propanol, 1-butanol, 1-pentanol, and 1-octanol, at 170 °C. The nucleation and growth processes of the ZnO nanoparticles were investigated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) characterization, and they were corroborated by means of quantum chemical calculations at the density functional theory level (DFT). On the basis of the results of joint microstructural and theoretical study, the nucleation and preferential growth mechanism of ZnO nanoparticles is proposed. The effect of various alcoholic solvent on the overall shape and growth rate along the preferential c-axis of ZnO nanoparticles were corroborated by means of theoretical simulations of interface-solvent interaction by using nanoclusters (ZnO) n (n = 12 and 36). The (ZnO)36–CH3(CH2) n OH (n ≤ 7) interaction has been found to be spontaneous exergonic process only in the presence of 1-butanol as reaction medium with ΔG*INT = −4.95 kcal mol–1, whereas endergonic in the presence of all remaining alcohols used (ΔG*INT > 0). The results of X-ray diffraction size-strain analysis reveal that solely the use of 1-butanol as solvent leads to rather isotropic crystallite shape (D v⊥c-ax ∼12 nm, D v∥c-ax ∼12 nm), whereas in the presence of all remaining alcohols used ZnO nanoparticles grew prevailing in the c-direction to form nanorods. The alcohols of different size and polarity acts as a solvent and reactant as well as controlling agents for crystal growth, providing different binding interactions involved in both the nucleation processes and preferential growth of ZnO nanoparticles. The calculated values of E O···H and E Zn–O of (ZnO)36–CH3(CH2)7OH (1-octanol) interaction indicate a weaker interaction of the nonpolar 1-octanol and polar a little positively charged Zn surface of ZnO crystal as well as a higher preferential growth rate along the c-axis in comparison to polar alcoholic media.

Antibacterial Activity of Solvothermal Obtained ZnO Nanoparticles with Different Morphology and Photocatalytic Activity against a Dye Mixture: Methylene Blue, Rhodamine B and Methyl Orange

“…Unfortunately, because only a 2 h reaction time was employed, the final product was impurified with zinc acetate. Increasing the reaction time to 4 h, at 170 °C, spherical and rod-like nanoparticles were obtained [ 21 ]. The computer aided modeling indicated the probability that the smallest crystallite would be obtained in n-butanol.…”

Synthesis of ZnO/Au Nanocomposite for Antibacterial Applications

“…SDBS ionizes entirely in water, and the resulting anion can be adsorbed onto certain crystal facets, leading to anisotropic growth of the particles. In the solvothermal synthesis of ZnO, water and ethanol can act as a solvent and reactants [ 52 ]. The differences in polarity and even in kinetic diameter of the two types of substances influenced the different stages of zinc oxide particle formation and even the possible aggregation of small particles [ 53 ].…”

Simultaneous quick-scanning X-ray absorption spectroscopy and X-ray diffraction

“…The solvothermal synthesis of ZnO nanoparticles was performed in a heated, hermetically sealed PTFEcell with Kapton windows for incident and transmitted X-rays [11], using solutions of 0.83 g Zinc acetylacetonate monohydrate (Zn(acac)2, Zn(C5H7O2)2 H2O) in 50 ml 1-octanol (CH3(CH2)7OH) as starting materials. According to the procedures described in [12], this precursor solution was heated to a temperature of ca. 165°C under continuous stirring, and the reaction was followed by time-and temperature-dependent EXAFS at the Zn K-edge and XRD with a repetition frequency of 0.5 Hz, i.e.…”