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