SINTESIS NANOKOMPOSIT Fe3O4/SiO2/TiO2 SEBAGAI FOTOKATALIS UNTUK FOTOOKSIDASI METILEN BIRU DAN FOTOREDUKSI ION PERAK(I); SYNTHESIS OF Fe3O4/SiO2/TiO2 NANOCOMPOSITE AS A PHOTOCATALYST FOR PHOTOOXIDATION OF METHYLENE BLUE AND PHOTOREDUCTION OF Ag(I) ION

PRADIPTA, ADYA RIZKY, Eko Sugiharto

2016 | Skripsi | FMIPA

Synthesis of Fe3O4/SiO2/TiO2 nanocomposites as a photocatalyst for photooxidation of methylene blue and photoreduction of Ag(I) ion has been carried out. The synthesis of Fe3O4/SiO2/TiO2 nanocomposites was firstly initiated by the synthesis of magnetite Fe3O4 through coprecipitation and sonication system, then coated with SiO2 via hydrolysis reaction, the TiO2 coating using sol-gel process with the addition of TiO2 degusa seed, followed by thermal treatment at 500 °C. The products were characterized using infrared spectrophotometer, X-ray diffractometer, transmission electron microscope, scanning electron microscope-energy dispersive X-ray, vibrating sample magnetometer, and diffuse reflectance spectrophotometer. The photocatalytic activity test of nanocomposite Fe3O4/SiO2/TiO2 was conducted for the photooxidation of methylene blue and photoreduction of Ag (I) ion. The photoactivity test was evaluated in a batch system using closed reactor equipped with UV light. The results indicated that the Fe3O4/SiO2/TiO2 nanocomposites have good photocatalytic activity. The Fe3O4/SiO2/TiO2 nanocomposites photocatalyst could also be used to catalyze the photooxidation of methylene blue and photoreduction of Ag(I) ion in a solution of AgNO3 under UV irradiation. The Fe3O4/SiO2/TiO2 nanocomposites has a better photooxidation and photoreduction capabilities than those of TiO2 unmodified. Photooxidation of 12.5 ppm methylene blue was optimum at pH 10 in the reaction time of 90 minutes, with the result was 97.4%. Photoreduction of 12.5 ppm Ag(I) ion was optimum at pH 6 in the reaction time of 120 minutes with the result was 98.6%.

Kata Kunci : TiO2, Ag(I) ion, methylene blue, photocatalyst