SINTESIS FOTOKATALIS TiO2-S DAN KINETIKA DEGRADASI METILEN BIRU; SYNTHESIS OF TiO2-S PHOTOCATALYST AND DEGRADATION KINETICS OF METHYLENE BLUE
Sofyurrizal Adi Tama, Eko Sri Kunarti
2014 | Skripsi | PROGRAM STUDI KIMIATiO2-S has been successfully synthesized The aim of this research is to study the effect of sulphur addition to the photocatalytic properties of TiO2 and the study of its photodegradation kinetics against methylene blue. Modification of TiO2 was conducted as follows; first thiourea was dissolved in ethanol and in to the solution, TiO2 powder was then added in various S/Ti molar ratio (5, 10, and 15%). The mixture was then calcined at 450 oC. The modified TiO2 was then named as TiO2-S. The TiO2-S was then characterized using FTIR spectroscopy, UV-Vis diffuse reflectance, powder XRD and scanning electron microscopy – energy dispersive spectroscopy (SEM-EDS) methods. Photoactivity tests was studied for the photodegradation of methylene blue in batch system in close reactor equipped with visible and UV light. The results showed that the FTIR spectra of TiO2-S confirmed the presence of S=O stretching vibration and Ti-O-S vibration at 1103 cm-1 and 1040 cm-1. Morphological analysis by SEM showed that the morphology of TiO2-S became an aggregate when compared with the morphology of TiO2 before any modification. EDS spectra indicated that the amount of S element that was successfully doped into TiO2 was only 1%. The band gap energy was decreased from 3.28 eV to 3.08 eV. In the presence of visible light, variation of S/Ti 10% performed the highest photocatalytic activity for the degradation of methylene blue, where 69.49% methylene blue was successfully degraded in 300 min with rate constant (k) 0.004 min-1. In the presence of UV light, 86.44% methylene blue was degraded with the k was about 0.02 min-1. The pure TiO2 was only able to catalyze the methylene blue photodegradation about 16.85% under visible light irradiation and 82.04% under UV light, with the k value of 0.0006 and 0.018 min-1, respectively.
Kata Kunci : TiO2-S; photocatalyst; methylene blue; visible light
