Caracterização estrutural e morfológica de compostos químicos para produção vítrea

Novais, Andréa Ferreira; Lima, Antonio Paulo Pereira; Santos, Arlan Rodrigo da Silva; Bezerra, Rodrigo Rangel Ribeiro; Ferreira, Fernanda Carla de Lima; Souza, Divanízia do Nascimento

doi:10.14808/sci.plena.2019.074810

Cited by 5 publications

(1 citation statement)

References 16 publications

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“…The corresponding XRD patterns are shown in Figure 11a. The typical XRD pattern of NaAuCl4 exhibits several sharp, intense crystalline peaks [50,51]. As expected, the obtained diffractogram showed this behavior.…”

Section: X-ray Diffraction Analysissupporting

confidence: 81%

Gold Nanoparticles: A Didactic Step-by-Step of the Synthesis Using the Turkevich Method, Mechanisms, and Characterizations

et al. 2023

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In this study, gold nanoparticles (AuNPs) were synthesized using the Turkevich method. This article explains the didactic step-by-step synthesis, showing pictures of the entire process, including a well-explained mechanism and characterization study. Synthesis involves the reduction of NaAuCl4 using sodium citrate at high temperatures (approximately 90 °C). The two main mechanisms used to explain AuNPs synthesis via the Turkevich method are also discussed. The first mechanism considers that a nanowire intermediary and the other proposes that aggregate intermediates are not formed at any time during the synthesis. The materials (NaAuCl4 and AuNPs) were characterized using UV-Vis spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and dynamic light scattering (DLS). The UV-Vis spectrum exhibits an absorption maximum at 521 nm because of the surface plasmon resonance (SPR) absorption band of the AuNPs. The SEM images of NaAuCl4 show crystals with cubic shapes, while the AuNPs have an average particle size of approximately 16–25 nm and particles that appear mainly spherical. To confirm the particle shapes, AFM was conducted, and it was possible to clearly observe individual spherical nanoparticles and their aggregates, and the average diameter of these AuNPs was approximately 12–19 nm. The XRD pattern of AuNPs showed four main characteristic peaks corresponding to the (111), (200), (220), and (311) planes, confirming the presence of cubic (FCC) gold. The DLS presented an average particle size of 3.3 ± 0.9 nm and a polydispersity index (PDI) of 0.574. AuNPs were synthesized using a simple and rapid method. The resulting spherical and ultra-small particles can be used in several applications.

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Section: X-ray Diffraction Analysissupporting

confidence: 81%