Cerium(III) nitrate hexahydrate [2 g, Ce(NO3)3·6H2O] was dissolved into 4.5M HNO3 (5 mL). Sodium hydroxide (10.50 g NaOH) was also dissolved into DI water (deionized water) (35 mL). This NaOH solution was then incorporated in to the Ce(NO3)3 solution by magnetic stirring at 50°C temperature. The magnetic stirring of solution was then continued for 2 hours. Consequently, a semi-transparent purpled colour colloidal solution was obtained. After that, the solution was kept at room temperature for 1 hour to cool down, and the cerium oxide (ceria) nanoparticles were separated from the solution by centrifuging it at a rate of 4000 rpm for 30 min. Following that, the ceria nanoparticles were washed several times with DI water and ethanol, after being washed the light yellowish ceria nanoparticles was obtained.