Nanosponge-C₃N₄ composites as photocatalysts for selective partial alcohol oxidation in aqueous suspension

A set of four composite materials was prepared, consisting of a nanosponge matrix based on β-cyclodextrin in which carbon nitride was dispersed. The materials were characterized by the presence of diverse cross-linker units joining the cyclodextrin moieties, in order to vary the absorption/release abilities of the matrix. The composites were characterized and used as photocatalysts in aqueous medium under UV, visible and natural solar irradiation for the photodegradation of 4-nitrophenol, and for the selective partial oxidation of 5-hydroxymethylfurfural and veratryl alcohol to the corresponding aldehydes. The nanosponge-C₃N₄ composites showed higher activity than the pristine semiconductor, which can probably be attributed to the synergic effect of the nanosponge, capable of increasing the substrate concentration near the surface of the photocatalyst.