Highly active CoNi nanoparticles confined in N-doped carbon microtubes for efficient catalytic performance

Engineering a tube-like architecture with bimetallic nanoparticles (NPs) has been considered an effective strategy for enhancing catalytic performance. Herein, we report a simple method for preparing one-dimensional (1D) carbon-based tubular composites incorporated with bimetallic active CoNi alloy NPs. CoNi alloy NPs were produced from the co-reduction of Co and Ni ions existing within a zeolitic imidazolate framework (ZIF)-based precursor and polydopamine (PDA) layer after N₂-protected thermal treatment. Moreover, the coated PDA outer layer was preserved for constructing a tubular structure, which eventually resulted in a composite of N-doped carbon microtubes (NCMTs) and CoNi NPs (CoNi@NCMTs). The resultant CoNi@NCMTs exhibited excellent catalytic activity for reducing 4-nitrophenol to 4-aminophenol. The synergy between the N-doped carbon microtubes and the well-dispersed bimetallic CoNi NPs provided outstanding catalytic performance, constructing inexpensive transition metal nanocatalysts. Moreover, the catalytic activity of the CoNi@NCMTs was well conserved even after five consecutive cyclic reactions. Importantly, hierarchical MoO₃@CoNi-LDH can be a good precursor to obtain tube-like structured CoNi-LDH, CoNi-LDH@SiO₂ and CoNi-LDH@NiMoO₄ composites.