Hierarchical confinement of Prussian blue nanoparticles via NH2-MIL-88B(Fe): Rational design and electrocatalytic application

Abstract

The design of Prussian blue nanoparticles (PB NPs) with satisfied electrocatalytic ability and stability is still challenging. Herein, a hierarchical confinement strategy of PB NPs is proposed using NH2MIL-88B(Fe) (denoted herein as NH2MIL) as both self-confined template and Fe3+ sources, K3[Fe(CN)3] as precursor. The catalytic synthesis of PB NPs is further achieved during the hydrothermal process at 100 °C for 1 h. The as-prepared PB@NH2MIL exhibits the morphology of “sea cucumber”, retaining the intrinsic skeleton of NH2MIL dotted with lots of PB NPs (<40 nm). In addition, the initial coordination of [Fe(CN)3]3- with the active free coordination sites of NH2MIL results in the coatom phenomenon between NH2MIL and PB NPs. Thus, the as-prepared PB@NH2MIL possesses the efficient electronic transmission, the enhanced electrocatalytic properties as well as stability under prolonged electrochemical measurements. Finally, the as-prepared PB@NH2MIL can be used as artificial peroxidase for the electrochemical detection of H2O2 with a wider linear range (0.01–1000 μM) and low detection limit (3 nM).