SYNTHESIS, CHARACTERIZATION AND TESTING OF MCM-41/TiO2 CATALYST FOR ORGANIC DYE DEGRADATION

This work focused on obtaining the MCM-41 substrate material and MCM-41 photocatalyst loaded with varying percentages of TiO2 (1 and 10%). Titanium dioxide precursor represented by titanium isopropoxide was introduced in mesoporous silica pores under vacuum, followed by hydrolysis. Synthesized powders were morphologically characterized by (SEM and HRTEM) and compositionally by (FTIR, EDAX, elemental analysis, XRD). The obtained results confirm the synthesis of MCM-41 mesoporous silica with hexagonal pores loaded with TiO2 nanoparticles. Synthesized powders were subsequently used in studies of azoic dye (tartrazine) adsorption/removal from aqueous solutions. Adsorption studies were carried out on a UV-VIS spectrophotometer at 427 nm. The determinations were carried out by contacting an amount of similar to 0.100g of MCM-41 powders, uncalcined MCM-41, MCM-41/1% TiO2, and MCM-41/10% TiO2 with 25 ml of tartrazine solution with constant concentration of 5 mg/L. The influence of contact time (0 to 216h) and the ability of synthesized powders to remove tartrazine were monitored. The degree of decolourisation after a 216h contact time with tartrazine solution varies as follows: MCM-41/10% TiO2 (100%) > MCM-41/1% TiO2 (99.88%) > uncalcined MCM-41 (99.12%) > MCM-41 calcined at 550 degrees C (17.64%).