High catalytic performance of gold nanoparticle–gelatin mesoporous composite thin films

Abstract

In this paper, Au nanoparticle (NP)–gelatin mesoporous composite thin films were successfully prepared by the formation of Au NPs in the mesoporous gelatin films through in situ reduction of HAuCl₄ at room temperature. The mesoporous gelatin films were prepared by using copper hydroxide nanostrands as both the assembling frames and the pore generators. It was found that both the trace aldehyde groups of the glutaraldehyde cross-linker and the reduction groups of gelatin contributed to the formation of Au NPs. The Au NPs were homogeneously formed and dispersed in the gelatin films. The effects of pH and the reduction time on the formation of the Au NPs were investigated in detail. These Au NP–gelatin mesoporous composite films demonstrated superior catalytic properties for the reduction of o-nitroaniline to 1,2-benzenediamine, and several to tens times higher activity than those reported of the Au NP–polymer (or oxide) composites. Similarly, Pt NP–gelatin mesoporous composite films were also prepared. This process is general and simple for other functional composite films.