Hierarchical assembly of CuO nanostructures for photocatalytic application

Herein we present a simple solution-based protocol to produce a highly efficient photocatalyst consisting of a 3D assembly of 2D nanostructures via one-pot synthesis. Such hierarchical assembly allow a very high surface/volume ratio and facing of active photocatalytic surface. Morphological and structural investigations of the as-grown CuO nanostructures have been performed by FESEM, STEM, HRTEM, SAED and XRD analyses. A detailed study of the photocatalytic activity has been carried out, comparing CuO with reference TiO2 nanoparticles: a very high photocatalytic activity has been measured, higher than that of commercial TiO2 and among the best reported in literature for CuO [1,2]. This can be tentatively ascribed to the synthetic procedure: on the one hand the hierarchical assembly exhibit a very high surface to volume ratio; on the other, the surfactant-free approach allows the whole surface of the nanostructure to be exposed to the chemical environment and hence maximize the photo-degradation of organic pollutants.