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

Abstract

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-C 3 N 4 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.

Composite RGO/Ag/Nanosponge Materials for the Photodegradation of Emerging Pollutants from Wastewaters

“…in nanoparticle form [11][12][13][14][15][16][17][18][19][20] is associated with a carbonaceous material such as graphene (G), graphene oxide (GO), or reduced graphene oxide (RGO) [21][22][23][24][25][26]. We have recently shown that significant activity enhancement can be achieved in this context by associating the photoactive species with a functional sorbent material such as a nanosponge (NS) [27,28]. In brief, NSs [29][30][31] are hyper-reticulated polymers constituted by supramolecular host units-cyclodextrins (CDs) in the most common cases, but also calixarenes (CAs) occasionally [32,33]-held together by suitable linker units.…”

“…In this way, six different composite photocatalysts were obtained (indicated as Cat1-Cat6), the performances of which were compared to those of plain RGOAg. We have recently shown that significant activity enhancement can be achieved in this context by associating the photoactive species with a functional sorbent material such as a nanosponge (NS) [27,28]. In brief, NSs [29][30][31] are hyper-reticulated polymers constituted by supramolecular host units-cyclodextrins (CDs) in the most common cases, but also calixarenes (CAs) occasionally [32,33]-held together by suitable linker units.…”