Skoltech researchers have investigated the process for catalyst supply utilized in the commonest methodology of carbon nanotube manufacturing, chemical vapor deposition (CVD), providing what they name a “simple and elegant” strategy to increase productiveness and pave the best way for cheaper and extra accessible nanotube-based know-how. The paper was published within the Chemical Engineering Journal.
Single-walled carbon nanotubes (SWCNT), tiny rolled sheets of graphene with a thickness of only one atom, maintain big promise on the subject of functions in supplies science and electronics. That’s the reason why a lot effort is concentrated on perfecting the synthesis of SWCNTs; from bodily strategies, equivalent to utilizing laser beams to ablate a graphite goal, all the best way to the commonest CVD strategy, when steel catalyst particles are used to “strip” a carbon-containing gasoline of its carbon and develop the nanotubes on these particles.
“The road from raw materials to carbon nanotubes requires a fine balance between dozens of reactor parameters. The formation of carbon nanotubes is a tricky and complex process that has been studied for a long time, but still keeps many secrets,” explains Albert Nasibulin, a professor at Skoltech and an adjunct professor on the Division of Chemistry and Supplies Science, Aalto College College of Chemical Engineering.
Numerous methods of enhancing catalyst activation, with the intention to produce extra SWCNTs with the required properties, have already been instructed. Nasibulin and his colleagues targeted on the injection process, specifically on tips on how to distribute ferrocene vapor (a generally used catalyst precursor) throughout the reactor.
They grew their carbon nanotubes utilizing the aerosol CVD strategy, utilizing carbon monoxide as a supply of carbon, and monitored the synthesis productiveness and SWCNT traits (equivalent to their diameter) relying on the speed of catalyst injection and the focus of CO2 (used as an agent for fine-tuning). In the end the researchers concluded that “injector flow rate adjustment could lead to a 9-fold increase in the synthesis productivity while preserving most of the SWCNT characteristics”, equivalent to their diameter, the share of faulty nanotubes, and movie conductivity.
“Every technology is always about efficiency. When it comes to CVD production of nanotubes, the efficiency of the catalyst is usually out of sight. However, we see a great opportunity there and this work is only a first step towards an efficient technology,” Dmitry Krasnikov, a senior analysis scientist at Skoltech and co-author of the paper, says.