Amorphous Co(MeIm)2 framework coating on AuCo for size-selective photocatalysis and interface transfer

Abstract

Porous metal–organic frameworks associated with functional materials have attracted considerable attention due to their excellent catalytic performance. In this work, AuCo–MeIm was synthesized by coating amorphous cobalt–methylimidazole [Co(MeIm)₂] frameworks on AuCo particles, which was also used as a Co(II) source for the construction of Co(MeIm)₂. TEM, XRD and TG results indicated the identification of amorphous Co(MeIm)₂ in the heterostructured composite. AuCo–MeIm showed size-selective catalytic performance in the photocatalytic removal of Cr(VI) and methylene blue attributed to the network of amorphous Co(MeIm)₂ coatings. Although Co(MeIm)₂ coatings contributed to the adsorption and photocatalytic degradation of MB by the affinity of aromatic rings and ligands for the metal charge transfer mechanism, the coatings still showed a significant inhibitory effect on the removal of methylene blue. This size-selective property was also well described by the proposed interface transfer kinetics.