In situ constructing heterostructure by synergizing the reaction thermodynamics and kinetics in thermal plasma: a case of silicon-carbon hybrid material

Abstract

In this work, silicon-carbon hybrid materials were adopted as an example to illustrate the novel strategy to in situ construct heterostructure with adjustable microstructure. Based on the temperature-dependent thermodynamics and kinetics of reaction between Si and C, the processes for Si nanocrystals growth and C decoration were coupled at different zones of plasma flame according to its temperature and velocity fields by theoretical modeling, aiming to intentionally suppress the formation of undesirable carbide, and enable adjusting the microstructure of each counterpart separately in transient process. As a result, well-controlled Si/C nanocomposites, including nanospheres and nanowires with core-shell structures, were achieved, and this continuous and in-flight route is also potential for large-scale production. Further investigation on the electrochemical properties highlights the advantage of as proposed strategy to efficiently construct heterostructures with superior performance for various applications.