THE INFLUENCE OF NaOH/NH3 RATIO ON THE SYNTHESIS OF NANOSTRUCTURED TiO2 VIA HYDROTHERMAL METHOD; PENGARUH RASIO NaOH/NH3 PADA SINTESIS TiO2 NANOSTRUKTUR DENGAN METODE HIDROTERMAL

Khairani, Inna Y, Indriana Kartini

2002 | Skripsi | FMIPA

The effect of alkaline solvent of NaOH and NH3 in the synthesis of nanostructured TiO2 has been studied. Powder of anatase titania as the precursor was mixed with various volume ratios of 10 M of NaOH and 15 M of NH3. The mixture was heated in Teflon-lined autoclave at 150 oC for 24 h. The as-synthesized TiO2 powders were then washed with 0.1 M HCl and calcined at 300 oC. The calcined samples were characterized using TEM (transmission electron microscope), SEM (scanning electron microscope), and XRD (X-Ray diffraction). Raman spectroscopy was further used to determine the contributing crystalline phases for the synthesized TiO2 at the solvent volume ratio of 3:1. Acid washing treatment of as-synthesized nanotubes enhances the transformation of titanate to anatase, but calcination at 400 and 500 oC ruins the nanotube morphology. The TEM images for the alkaline variation showed the formation of nanotube structure in alkaline ratio NaOH:NH3 of 1:0 and 3:1, with diameter of about 10 nm, while at ratio of 1:1, the nanosheets and nanotubes both were formed at equal amount. Volume ratio of NaOH:NH3 of 1:3, nanosheets contributed as its main morphology. The crystallinity of TiO2 anatase crystalline phase was enhanced as more NH3 utilized. The result showed that the major contributor was anatase with slight presence of titanate. Therefore, NaOH:NH3 alkaline ratio of 3:1 (v/v) was optimum to produce anatase nanotubes.

Kata Kunci : hydrothermal method; nanotube; titania; alkaline; nanosheet; anatase