Silver nanoparticle doped titanium oxide photocatalyst material is intercalated into chemically activated lateritic clay (CLY) minerals using sol-gel technique for the preparation of powder ceramic nanocomposite photocatalyst. The photocatalyst nanocomposites were sintered at high temperature to induce thermal reaction and crystalline growth between the constituents via Oswald ripening. Physical and thermal characterizations of intercalated (STOX-C) and sintered-intercalated (STOX-CS) samples were studied using BET (N2 adsorption-desorption analysis), differential scanning calorimetry (DSC/DTA), and scanning electron microscopy (SEM). Microstructural examination of Ag-NPs doped TiO2 revealed evenly distributed uniform nanocrystallites after the sol-gel synthesis. The micrograph of the clay mineral samples indicated transition from a combination of rod-like and platelet phases to aggregates of spherical crystallites after intercalation and sintering. The natural structure of the clay mineral changed after sol-gel intercalation with Ag-TiO2 nanoparticle. Nitrogen adsorption-desorption analysis of the samples revealed that nanoparticle intercalation does not really affect the particle surface area, however isothermal sintering after intercalation caused remarkable reduction in crystallites surface area (37.912 m2/g to 8.971 m2/g). Meanwhile, the pore sizes increased after sintering from 17.47 nm to 24.42 nm. Changes from hysteresis loop to a nearreversible isotherm behaviour were observed after photocatalyst nanoparticle sintering. The thermal analysis revealed transformation reactions of lateritic mineral influenced by between Ag-TiO2 intercalation.

Keywords: Sol-gel, Adsorption-desorption, Nanocomposite, Sintering, Lateritic clay.