2.2 Synthesis of nickel ferrite on silica substrate (NiFe2O4@SiO2)
The synthesis method of magnetic nickel ferrite nanocomposite on a silica substrate is in accordance with the Gharagozlou M. et.al. method reported in the sources [25]. Nickel ferrite has weight ratios of 10, 30, and 50 percent to the 90, 70 and 50 weight percent of silica substrate respectively.
In this method, the nickel nitrate and iron nitrate were weighed in the amount of 6 and 9 grams respectively, and dissolved in 10 ml of deionized water under reflux conditions and stir well with a mechanical mixer for 30 minutes to mix thoroughly. Next step, pour 60 ml of tetraethyl ortho silica (TEOS) into 50 ml of ethanol and 10 ml of water and acidify its pH using hydrochloric acid, and then pour it into the decanter and add it drop by drop to the solution inside the balloon and allow to stir for 2 hours for further mixing. In the third step, the contents of the balloon are poured into the crystallizer and placed slightly in the exposure of air for 7 days, and the alcogel is obtained. After 7 days, place the resulting alkogel in an oven at 110 oC for 24 hours to allow it to dry and xerogel obtain. The xerogel were calcined for 2 hours in an oven at 800 oC with a heating rate of 10 oC/min and the product were milled by a satellite mill.