A facile route to well-dispersed Ru nanoparticles embedded in self-templated mesoporous carbons for high-performance supercapacitors

Abstract

To date, the facile preparation of ruthenium nanoparticles homogeneously dispersed in mesoporous carbons remains a big challenge. Here, a poly(butyl acrylate)-b-polyacrylonitrile block copolymer was dissolved in dimethyl sulfoxide with ruthenium(III) acetylacetonate (Ru(acac)₃) and then pyrolyzed after electrospinning. Ru(acac)₃ was confined in the polymer network and converted to RuO₂, which was further reduced to Ru nanoparticles (Ru-NPs) at high temperature, eventually producing well-dispersed Ru-NPs embedded in STMCs (Ru-NPs@STMCs). The as-prepared Ru-NPs@STMCs show many attractive features, such as spherical shape with a high surface area, numerous active species (Ru and N), and an interconnected structure with meso/micropores, resulting in fast mass transport and ion diffusion pathways. The synergetic effect of Ru-NPs and STMCs gives rise to excellent electrochemical performance, with a very high specific gravimetric capacitance of 656.25 F g⁻¹ at a scan rate of 10 mV s⁻¹, good rate capability, and excellent long-term cycling stability (almost 100% retention after 5000 cycles). To our knowledge, this performance is one of the best results reported for Ru/carbon-based materials and is comparable to that of other RuO₂/carbon-based materials. This study not only gives insights into the design and construction of novel nanocomposites for high-performance supercapacitors but also provides a new approach to engineering metal/carbon composites applicable to energy storage and energy conversion devices.