Nanocomposites that incorporate TiO2 and ZnO nanoparticles separately in three-dimensional solgel matrices through full chemical integration are prepared to perform highly efficient photocatalytic activities for applications of environmental decontamination. Spectral responses of photocatalytic TiO2 and ZnO nanoparticles exposed to UV activation for self-cleaning process were obtained as also their optical relative spectral efficiency curves from 270 to 370 nm in the UV regime. Our investigations of the optimal conditions to increase their spectral photocatalytic efficiencies resulted in remarkably high levels of optical recovery and efficiency.