P17-11 Acidic plant extracts to reduce the particle size of ZnO nanostructures biosynthesized with Brassica oleracea italica R. Ángeles Sierra 1; M. Villanueva-Ibáñez1,*; R. González-Montes de Oca 1; P.N. Olvera-Venegas 1; M.A. Hernández-Pérez 2; M.A. Flores-González 1. 1
Universidad Politécnica de Pachuca. Zempoala, Hidalgo, México 2 Departamento de Ingeniería en Metalurgia y Materiales, ESIQIE-Instituto Politécnico Nacional. México *villanueva@upp.edu.mx
Abstract The properties of ceramic materials at the nanoscale have significantly increased their demand in different industrial sectors. Zinc oxide (ZnO) has many attractive properties, such as the direct wide bandgap (3.37 eV), good electrical characteristics, chemical stability, biocompatibility and antibacterial activity, which suggest a variety of possible practical applications. Different synthesis methods have been reported to prepare nanocrystalline zinc oxide; most of them require expensive high technology or depend on the use of toxic reducing agents [1]. In this work, we report a simple ecofriendly synthesis to obtain zinc oxide nanomaterials from zinc acetate solutions using extracts of Brassica oleracea italica as reducing agent. The addition of acidic plant extracts to the as-obtained materials had a positive effect on the reduction of the original particle size, maintaining stable colloidal solutions for more than one week. This work extends the possibilities of the use of biotechnological methods for other applications of technological interest.
Results Methodology Table: 1 Qualitative Phytochemical screening of Brassica oleracea italic extract.
Characterization of aqueous extract of Brassica oleracea italica by phytochemical
Brassica oleracea itálica
Synthesis of ZnO with extract of Brassica oleracea italica, and monitoring by UV-vis.
Saponins
Tannins
Lactsona
Flavonoids
+
+
+
+
+
+
Synthesis and characterization of biosynthesized ZnO
b b
a Characterization of ZnO nanostructures using MEB, Raman spectra, laser particle size, and XRD.
c ZnO-B
Figure 2a) shows the whitish appearance of the ZnO synthesis; b) UV-vis spectrum with an absorption band at 378 nm characteristic of ZnO; c) luminescence spectrum with a emission band at 380 nm belonging to ZnO [3].
c
101
bb
112
103
En
110
102
100
002
a Characterization of the dispersed particles, by photoluminescence spectrum and Raman spectrum.
Carbohydrates
Figure 1. This preliminary study shows de presence of type of metabolites that may be involved in the synthesis of ZnO.
.
Dispersion of ZnO nanostructures by organic acids belonging to plants.
Sugars
Figure 3a) SEM of the synthesized ZnO, with particle sizes of 100 nm and morphology with triangular prisms. b) Raman spectra of ZnO obtained with chemical synthesis [2], ZnO as-synthesized with Brassica oleracea italic extract (ZnO-B) and ZnO biosynthesized with other plant extract (Blue). c) ZnO DRX shows Wurzite hexagonal structure of ZnO-B [3].
a Conclusions Metabolites that favor the synthesis of ZnO (sugars and antioxidants) were found in Brassica oleracea italica extract. It was possible to synthesize ZnO mediate a green method (bioreduction) ZnO nanostructures without any additional phase corroborating the XRD. With the use of the organic acids belonging to the plants, the size was reduced to 50% and stabilized ZnO in the medium.
b
c
Figure 4, a) Granulometry shows the particle sizes of ZnO as-synthesized (black, 630 nm), the others samples present particles sizes de 280 nm (red, green and blue) b) the luminescence spectrum is shown with a band of emission at 380 nm belonging to ZnO, [4] c) MEB of the dispersed nanoparticles, with sizes of 41 nm and 67 nm.
References [¨1] Baruah,, S., & Dutta,, J. (2009). Hydrothermal growth of ZnO nanostructures. Science and Technology of Advanced Materials,. [2] Bharathi, M. S. (2015). Plant-extract mediated synthesis of ZnO nanoparticles using Pongamia pinnata and their activity against pathogenic bacteria. Advanced Powder Technology. [3] Martínez, D. N. (2013). Crecimiento Cristalino de nano y microestructuras de ZnO mediante PVD. Departamento de Física Aplicada y Electromagnetismo, 5-218 [4] Shakeel Ahmeda, ,. ,. (2017). A review on biogenic synthesis of ZnO nanoparticles using plant extracts and microbes: A prospect towards green chemistry. Journal of Photochemistry and Photobiology B: Biology, 272-284.