Journal
MATERIALS
Volume 16, Issue 6, Pages -Publisher
MDPI
DOI: 10.3390/ma16062159
Keywords
nanopigments; ZnO nanocrystals; NIR reflectance; thermal decomposition; surface modification; oleic acid; cool-nanopigment applications
Ask authors/readers for more resources
As-synthesized and oleic acid (OA)-surface-treated zinc oxide (ZnO) nanocrystals are successfully synthesized and investigated for cool-nanopigment applications. The structural, optical, and morphological properties of the samples are characterized. Surface modification of the ZnO by OA leads to decreases in crystallite size and surface area, as well as a blue shift in the optical band gap. Both samples show high NIR reflectance values, qualifying them as cool nanopigments.
In this paper, as-synthesized and oleic acid (OA)-surface-treated zinc oxide (ZnO) nanocrystals were successfully synthesized and investigated for cool-nanopigment applications. ZnO nanocrystals were synthesized using the thermal decomposition method. The OA-surface-treated ZnO sample was obtained with an OA:ZnO ratio of 1:1. The structural, optical and morphological properties of the samples were characterized via X-ray diffraction (XRD), Fourier transform infrared (FTIR), UV-VIS-NIR diffused reflectance spectroscopy (DRS) and field-emission scanning electron microscopy (FE-SEM) techniques. ZnO nanocrystals possess a well-known zincate phase of ZnO, as confirmed for the as-synthesized sample with a reduction in the integrity of the ZnO crystalline structure upon the application of the OA coating. XRD peaks broadening and decreasing in crystallite size were obtained upon the surface modification of the ZnO by OA. The average crystallite size decreased from 31.5 to 17.4 nm, and the surface area changed from 23.37 to 7.48 m(2)/g upon OA treatment. These changes were attributed to the well-capping of the ZnO nanoparticles by OA, and, furthermore, OA increased the dispersion of the nanoparticles. The optical band gap of the investigated samples demonstrated a blue shift from 3.06 eV to 3.22 eV upon treatment. Both samples showed high NIR reflectance (RNIR*) values, which makes them well qualified for use as cool nanopigments. Additionally, the as-synthesized sample showed an RNIR* value higher than that of the treated sample.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available