SINTESIS Fe(II), Co(II) DAN Ni(II) DOPED TiO2 DENGAN METODE SOL?GEL SERTA UJI FOTOAKTIVITASNYA PADA DEGRADASI BIRU METILENA; SYNTHESIS OF Fe(II), Co(II), Ni(II) DOPED TiO2 BY SOL?GEL METHOD AND THEIR PHOTOACTIVITIES FOR EXAMINATION DEGRADATION OF METHYLENE BLUE

Herawan, Prasetyo, Harno Dwi Pranowo

2015 | Tesis | FMIPA

In this study, there was synthesis of TiO2 photocatalyst powder with Fe(II), Co(II) and Ni(II) cation dopants or MT-TiO2 using sol?gel method. Adding dopants was expected to decrease the energy of bandgap (Eg) and repairs the TiO2 photoactivity ability. The synthesis parameters studied included; dopant percentage, pH of dopant salt solution and calcination temperature. Photocatalyst synthesis was conducted by dropwise dopant salt solution into titanium (IV) isopropoxide (TTIP) in isopropanol. Dopant percentage was varied from 1 to 5%. pH of dopant salt solution an calcination temperature variations were at 3% dopant percentage. pH of dopant salt solution was varied from pH 1 to 9 and calcination temperature was varied from 300 to 700 ºC. Pure TiO2 without addition of chloride salt dopant was synthesized as control experiment. Electronic absorption characterization of photocatalyst was measured by Specular Reflectance-UltraViolet/Visible (SR-UV/Vis) spectrophotometer, diffraction pattern was measure by X-Ray Diffraction (XRD) and vibration energy was measured by Fourier Transform Infra Red (FTIR) spectrophotometer. Advanced characterizations of photocatalyst on the morphology and composition of the elements were measured by Scanning Electron Microscopy-Energy Dispersive X-Ray Spectrometry (SEM–EDX) and particle size was measured by Transmision Electron Microscopy (TEM). At the end of the experiment, photocatalyst photoactivity examination was conducted on methylene blue degradation. Based on SR-UV/Vis and XRD data on dopant percentage variation, Ni-TiO2 3% was the most responsive to absorption shift in visible light, because Eg was 2.99 eV and the smallest crystallite size was 8.64 nm. In dopant percentage variation, all TiO2 with dopant had smaller Eg than pure TiO2, which was 3.17 eV. At pH 1 dopan salt solution variation, Fe-TiO2 3% had the smallest Eg, which was 2.67 eV and smallest crystallite size anatase phase which was 11.13 nm. At calcination temperature 500 ºC, Ni-TiO2 3% had the smallest Eg value, which was 2.99 eV, and Co-TiO2 3% had the smallest crystallite size anatase phase, which was 10.07 nm. The higher the calcination temperature, the more crystal phase is transformed from anatase phase into rutile phase, causing crystal size to increase. Fe(II), Co(II) and Ni(II) cation dopant had entered the lattice of TiO2 crystallite, proven by the detection of Fe, Co and Ni in the results of SEM-EDX. Photoactivity examination of photocatalyst products was conducted in photocatalytic reactor equipped with 6000 K xenon lamp. Photodegradation for 1.5 hours by Fe-TiO2 1% photocatalyst with photocatalyst content in 1 g L-1 suspension in 50 mL in methylene blue solution with 10 ppm initial concentration was able to degrade 80.9% blue methylene blue with kr 0.017 minute-1. Key words: Doped TiO2, Fe(II), Co(II), Ni(II), sol?gel, photoacti

Kata Kunci : Doped TiO2; Fe(II); Co(II); Ni(II); sol?gel; photoactivity