Europium Complex Incorporated Mesoporous Silica for a Potential pH Sensor

Highly ordered mesoporous silica, SBA-15 was synthesized using triblock copolymer (P123) as template and tetraethyl orthosilicate (TEOS) as silica source. Through the post-synthesis treatment, pore surface of the mesoporous silica was modified with aminosilane and then Eu3+ ions were incorporated in the modified mesoporous silica for the formation of Eu complex. Mesoporous silica with the hexagonal mesostructure was characterized by small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). The successful modification of the mesoporous silica was verified by FT-IR spectra and nitrogen adsorption/desorption isotherms. Eu incorporated mesoporous silicas showed different photoluminescent intensities depending on the pH of acidic and basic aqueous solutions.