Photocatalysts and composite catalysts are prepared by various methods, including batch synthesis, combinatorial synthesis and spray pyrolysis. Catalysts have either a powder structure from nano to micrometer scale or a capsule structure. 

STEM image of Ag doped TiO2 powder
Various silver / TiO2 ratio
SEM picture of the high-area TiO2 sample, obtained at ICSC by depositing sol-gel prepared TiO2 on template after removing the template.