Transient and scalable synthesis of metal-carbon nanocomposites by thermal plasma with self-coordinated mechanism

Abstract

In this work, an in situ strategy was developed to construct various metal-carbon heterostructures with high yield. Notably, the multi-step reactions and structural regulation were completed in milliseconds due to the greatly enhanced kinetic driving force originated from the ultra-high temperature and ionized reactive atmosphere in thermal plasma, resulting in ultrasmall metal nanocrystals with size about several nanometers embedded in high-crystalline and nitrogen-doped porous carbon nanolayer. Based on controlled experiments, a self-coordinated mechanism involved the catalytic effect of metal species and the confined growth function of C was proposed to clarify the formation of heterogeneous nanocomposites. Furthermore, the advantage of synthesized heterostructure was illustrated by its superior performance of electrocatalytic hydrogen evolution from water splitting. The obtained dual CoNi@NC presents a competitive overpotential of 149 mV to deliver a current density of 10 mA cm−2, together with 98 % preservation of initial capacity after 20 h test, highlighting the universality of this work to construct well-designed metal/C nanocomposites with potential engineering application in electrocatalytic field.