In situ assembling of layered double hydroxide to magadiite layered silicate with enhanced photocatalytic and recycling performance

Abstract

The global concern of the future consequence of non-controlled industrial development is boosting the emergency of sustainable materials composed by earth abundant elements that can be applied in the remediation of natural resources like accesible water. A new type of heterostructured material was synthetized using as strategy the assembly of 2D layered double hydroxide (LDH) based in unexpensive metals, like MgAl and ZnAl on the 2D synthetic philosilicate magadiite through an in situ co-precipitation method. Several physicochemical techniques were employed to characterize the materials with the aim to ascertain the existence of interactions at the interface of both components. ZnAl based heterostructure was then derived by thermal trateatment in a second heterostructure with highly disperse metal oxide nanoparticles supported on the 2D silicate (magadiite). These heterostructures were evaluated as photocatalysts in a model reaction, reveling that the presence of magadiite as support of metal-oxide nanoparticles contributes to enhances the photocatalytic activity (84% in 60 min), stability and recyclability of the nanoparticles with an easier recuperation. A deeper study on the catalyst mechanism reveals that hydroxyl radicals and photogenerated holes are the main active species, meanwhile photocurrent tests pointed out a suppressed recombination of photogenerated electron-hole pairs in magadiite-supported metal-oxide nanoparticles.