Ultrathin noble metal nanoplates decorated metal-organic framework nanosheets as 2D/2D heterojunction nanobionic catalysts for explosive residues monitoring

Abstract Compared with conventional bulk 3D metal-organic framework (MOF), the MOF nanosheets possess large surface area, ultrathin thickness, and well solution dispersion properties, which is suitable to be used as novel templates to synthesize the functional composites. However, up to now, it remains difficult to grow noble metal nanoplates on 2D MOF surface due to the complexity of synthetic process. Here, for the first time, we used MOF nanosheets (Cu-TCPP or Cu-TCPP(Fe)) as an template for the solution-phase growth of silver (Ag), gold (Au), and palladium (Pd) nanoplates at ambient conditions. The noble metal plates on the surface of 2D MOF are uniform and possess ultrathin structure, which are the ideal materials for catalysis due to accessible active sites, fast electron transfer, high stability, and good solution-dispersion. Notably, the synthesized Pd/Cu-TCPP(Fe) hybrid nanomaterials shows enzyme-mimic catalytic activity, which exhibits enhanced catalytic performance compared to Pd nanoplates, MOF nanosheets, and their mixture. Owing to their high catalytic activity, a simple, fast and highly sensitive fluorescence method was developed to detect explosive residues such as organic peroxides in trace amounts, which existed widely in the environment.