PHOTOGENERATION OF NANOSIZED GOLD ON THE SURFACE OF MESOPOROUS SILICA MODIFIED BY BENZOPHENONE

We have studied the photocatalytic activity of porous silicas (silica gel, mesoporous sol–gel films) modified by benzophenone molecules, in the reaction of reduction of gold from tetrachloroaurate ions. Stable colloids of nanosized gold were obtained as a result of irradiating aqueous alcoholic solutions of HAuCl4•3H2O in the presence of the photocatalyst SiO2-BP using as the stabilizers: a colloidal solution of silica (Ludox) or the surfactant sodium dodecyl sulfate (SDS). We have studied the effect of the stabilizer on the kinetics of the photoreduction reaction, and also on the shape and size of the nanoparticles formed.