BIOSYNTHESIS OF CERUM OXIDE (CEO2) NANOPARTICLE USING MORINGA OLEIFERA LEAF EXTRACT FOR SUNSCREEN APPLICATION WITH CHARACTERIZATION AND DENSITY FUNCTIONAL THEORY SIMULATION

• Main Author: Hidayat, Satria
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/67381
• Institution: Institut Teknologi Bandung

Metal oxide nanoparticles such as ZnO, TIO2, and CeO2 can be used as active ingredients in sunscreens to counteract ultraviolet radiation. This research, CeO2 nanoparticles were synthesized using Moringa leaf extract as a reducing agent. Two stabilizers PEG40-HCO and sodium citrate were used to overcome the high nanoparticle agglomeration. The addition of metal dopants Ag, Ca, Ni, and Zn was carried out to evaluate the effect of the dopant on the electronic and optical properties of CeO2 nanoparticles. Doped an pristine CeO2 nanoparticles were further characterized by TG/DTA, FTIR, XRD, TEM, PSA, and UV/Vis tests. The photocatalytic activity was observed using the rancimat test to determine the effect of the addition of dopant on the induction time of nanoparticles in the medium. The TG/DTA test showed no significant mass loss above temperature of 500oC. The XRD test showed the main peaks of the fluorite phase at the Miller indices (111), (200), (220), (311), (222), (400), (331), (420), and (422), and crystallization size ranged from 16 nm to 39 nm. The FTIR test showed the peak of the Ce-O vibration at a wave number of ~469 cm-1. The morphology of the nanoparticles was tested using TEM, and it was found that the nanoparticles had a semi-spherical shape with various grain sizes from 30 nm to 50 nm. The PSA test obtained information on the distribution of nanoparticles agglomeration in two different groups except for CeO2 with the addition of Zn dopant, which only had one large distribution. Based on the UV-Vis test, the presence of dopant in CeO2 nanoparticles showed that the absorption value are red shifted. Bandgap energy values obtained using the tauc plot method and analytically indicate that the presence of dopant reduces the bandgap energy value. The results of the rancimat test showed that the addition of dopant slowed the induction time, reducing the photocatalytic activity. Computational studies show that the absorption value of CeO2 is per the experimental results with the absorption peak in the UV range.