Burning a candle infused with various metal precursors can yield carbon soot nanoparticles that encompass as many as 25 different metals. The scientists involved in the study indicated that this technique might present a viable avenue for the advancement of electrocatalysts.
Producing high-entropy metal-based nanomaterials typically necessitates extreme conditions, such as elevated pressures and temperatures exceeding 1000K, along with highly specialized apparatus. In this research, a consortium of scientists from China and Australia showcased a flame synthesis method where paraffin wax was infused with organometallic precursors prior to lighting the candle. Once ignited, the metal precursors traveled alongside the paraffin wax via capillary action along the wick, moving from the central part to the outer flame area.
The flame inherently created a stable and broad temperature gradient from the flame’s center, approximately 1800K, to the stainless-steel soot collector positioned about 20mm from the burning wick. The flame’s extreme heat facilitated uniform bonding among different metallic elements, leading to the formation of minuscule metal-containing carbon soot nanoparticles.
The researchers examined the physicochemical characteristics of the nanoparticles through electron microscopy and discovered them to be roughly 40nm in diameter, exhibiting an onion-like layered configuration, a large surface area, and minimal electrical resistance.
With this method, as many as 25 metals were successfully integrated into a single soot nanoparticle, and the team noted that the composition of the soot nanoparticles could be adjusted, with the technique easily scalable, rendering it a promising strategy for numerous catalytic processes.
Additionally, the team illustrated the potential use of a high-entropy metal nanoparticle that incorporates iron, cobalt, nickel, copper, and palladium for the electrocatalytic generation of hydrogen peroxide.