Catalyzing "C network" by Mo-Fe-S NPs for driven growth of CNTs arrays

During the catalytic growth of CNTs, the ordered arrangement of catalysts is critical for maintaining their array structure. Unlike mechanisms that suppress nanoparticle migration via high catalyst density to enforce CNTs array growth, this study proposes a strategy involving surface engineering and nanoparticle nucleation to construct Mo-Fe-S/Al 2 O 3 heterogeneous ternary catalysts. This method modulates the electronic density of Fe sites to activate catalytic activity while constructing Mo-Fe-S sites on the catalyst surface to catalyze the growth of a "C network" (carbon pillars and CNTs), thereby forming CNTs arrays. On one hand, S and Mo weaken the interfacial interactions between Al 2 O 3 and inactive FeO x nanoparticles, promoting active particle nucleation; on the other hand, the "C network" grown via Mo-Fe-S constitutes the top part of the CNTs arrays, confining the internal nanoparticles (NPs) to enable vertically aligned growth of CNTs. Characterizations reveal NPs with diameters of ∼20 nm and symmetrically grown CNTs arrays with average diameters and heights of 18.21 nm and 10.10μm, respectively. This work provides an approach for the catalytic growth of CNTs arrays using supported catalysts, by forming a "C network" to suppress the entanglement of NPs during the catalytic growth of CNTs, thereby forming the CNTs array structure.