Fabrication of noble metal nanoparticles decorated on one dimensional hierarchical polypyrrole@MoS microtubes.

MoS-based hybrids have aroused great interest for their outstanding performance in the application fields of biochemical sensing, catalysis and energy storage. Herein, we present a facile strategy to fabricate hierarchical microtubes by cultivating a MoS sheet-like nanostructure on polypyrrole microtubes (designated as PPy@MoS microtubes) using MoO@PPy micro-cables as self-sacrificial templates. Such a dissolution-regrowth mechanism is demonstrated for the formation of hierarchical PPy@MoS microtubes by studying the morphology of the intermediate products in the process of the sulfidation reaction. The PPy microtubes are able to effectively improve the electrical conductivity of the hybrid architecture and greatly alleviate the agglomeration of the MoS nanosheets. Notably, the sheet-like MoS nanostructure can load more noble metal nanoparticles (NPs) owing to MoS released photogenerated electrons irradiated by light. Then, metal (Ag, Au, and Pd) NPs are reduced and in situ decorated on PPy@MoS microtubes, thus forming ternary PPy@MoS@Ag, Au, and Pd nanohybrids, respectively. This decoration method also expands the wide range of application fields of PPy@MoS. As a proof of application, the ternary PPy@MoS@Au hybrids reveal excellent enzyme-like catalytic performance. Owing to the high coverage of Au NPs as well as one dimensional hierarchical MoS-based ternary unique structures, the resultant PPy@MoS@Au hybrid composites exhibited synergistically enhanced peroxidase-like catalytic activity relative to MoS, MoS@Au, and PPy@MoS alone, demonstrating the remarkable prospects of MoS-based hybrids in chemical/biological molecule sensing application.