Single Wall Carbon Nanotubes Synthesis through Methane Chemical Vapor Deposition over MCM-41–Co Catalysts: Variables Optimization

摘要

MCM-41–Co catalysts were tested in the synthesis of single wall carbon nanotubes (SWCNTs) through methane chemical vapor deposition (CVD), varying total cobalt content, synthesis temperature, methane flow rate, and deposition time. All variables showed a relationship with total carbon deposition, graphitic quality according to Raman results. Cobalt content showed a maximum activity at 4%, but the structural quality is best at 3%. Flow rate does not affect the quality up to 300 cm 3 min ?1 , but deposition time leads to the formation of highly disordered carbon species passing methane for periods longer than 30 min, concluding that optimal variables are a methane deposition temperature of 800 °C, a 300 cm 3 min ?1 methane flow rate, and a 30 min of methane injection time, leading to a 5.4% carbon mass content and 5.1 G/D area ratios.