Effect of Binder on the Structure and Properties of Silicon Powder-supported TiO2 Photocatalysis Mat

Recoverable TiO2 photocatalysis material supported by silicon powder was pre- pared with sol-gel method, afterwards the silica gol and sodium silicate were used as molding binder respectively to investigate their effects (including binder type and binder addition quantity) on the crystal structure and catalysis properties of photocatalyst. In this work, the catalysis activity was defined as the degradation rate of methyl orange solution upon ultraviolet lamp irradiation, and the specific areas were determined with nitrogen desorption method. TiO2 crystal form was measured with X-ray powder diffraction and their micro-morphology was observed with SEM. Experimental results indicate that these two binders do not affect the crystal form transformation of TiO2, but silica gol can increase the specific surface area of TiO2 photocatalyst obviously and the addition of sodium silicate can decrease it. In all, silica gol is a better candidate than sodium silicate for higher catalysis property. In conclusion, 6% silica gol is the optimal addition concentration. Under this condition, the ratio of anatase to rutile TiO2 is 64:36, the specific area is 29.67 m2/g, and as expected, the degradation rate of methyl orange could be as high as 90% after irradiation for 5 days.