Facile encapsulation strategy for uniformly-dispersed catalytic nanoparticles/carbon nanofibers toward advanced Zn–air battery

Abstract

Catalyst-loaded carbon nanofibers (CNFs) have been a promising platform to enhance the efficiency of key electrochemical reactions, crucial for the operation of fuel cells, metal–air batteries, and the reduction of pollutants. A persistent challenge, however, has been the uniform distribution and strong binding of ultrafine active catalytic nanoparticles on the CNF surfaces. To overcome this issue, this study introduces a facile synthesis strategy using electrospun blended nanofibers of polyacrylonitrile and poly(4-vinylpyridine) (P4VP) for the uniform attachment of various metal catalyst ions. Metal complex ion precursors are selectively loaded into P4VP domains and subsequent one-step pyrolysis to readily obtain CNFs densely populated with uniformly dispersed metal nanoparticles enveloped by a P4VP-derived nitrogen-doped carbon layer. The final C@Ir/CNF1000, composed of iridium nanoparticles (average diameter: ∼3.38 ± 1.18 nm) on CNFs with a carbon overlayer and carbonized at 1000 °C, significantly improves the dual-functionality and cycle stability of zinc–air batteries. Our findings present a novel and scalable strategy for improving catalytic efficiency in energy technologies, marking a significant contribution to the field of sustainable energy and environmental applications.