Synthesis of TiO2 – M (Cd, Co, Mn) as a Photocatalyst Degradadion of Methilene Blue Die

TiO2-M (M = Cd, Co, Mn) were synthesized by sol-gel method using titanium(IV) isopropoxide (TTIP) and cadmium sulfate octahydrate (CdSO4.8H2O), manganese(II) sulfate monohydrate (MnSO4.H2O), cobalt(II) sulfate heptahydrate (CoSO4.7H2O) as precursors. M-doped TiO2 was performed with molar ratio 1:3; 1:2; 1:1; 2:1; 3:1 (mol Ti / mol M) and photocatalytic processes using visible light with irradiation time for 5, 10, 15, 20, 25 and 30 minutes. This study was carried out to determine the effect of different metal ions, the composition of Ti:M and the exposure time on the photocatalytic degradation of methylene blue dye. The results showed that different metal ions influenced crystal size and affected electronic properties (band gap). Crystal size of TiO2 > TiO2-Mn > TiO2-Co > TiO2-Cd and band gap of TiO2 > TiO2-Cd > TiO2-Co > TiO2-Mn. In addition, differences of Ti:M composition also influenced the photocatalytic activity. The longer of applied time exposure, the higher photocatalytic degradation of methylene blue was achieved. The optimum composition of Ti:M was obtained at Ti:M ratio by 3:1 with degradation values by 92.56% (TiO2-Cd), 90.44% (TiO2-Co), and 89.42% (TiO2-Mn).