Low-temperature growth at 225 °C and characterization of carbon nanowalls synthesized by radical injection plasma-enhanced chemical vapor deposition

The synthesis of carbon nanowalls (CNWs) necessitated a substrate heating temperature above 600 °C. This study describes a low-temperature growth at 225 °C and characterization of CNWs synthesized by the radical injection plasma-enhanced chemical vapor deposition. To investigate the effect of temperature on the growth process, CNWs were synthesized at various temperatures ranging from 200 °C to 700 °C. The morphology of the CNWs observed with a scanning electron microscope shows that wall density increases as substrate temperature decreases. The Raman spectroscopy analysis indicates that CNWs grown at 225 °C have higher defect levels than those grown at higher temperatures, such as 700 °C. Transmission electron microscopy confirmed the presence of multiple graphene layers in the CNWs grown at 225 °C. The water contact angle results revealed that CNWs grown at 225 °C had higher hydrophobicity than those grown at higher temperatures, opening up the potential for CNW applications. [Display omitted] •Carbon nanowalls (CNWs) are grown at a low temperature of 225 °C.•A possible growth mechanism of the CNWs at 225 °C including 4 stages is proposed.•CNWs grown at 225 °C show a better hydrophobicity than typical CNWs grown at 700 °C.•Effect of substrate temperature on the growth process of CNWs is revealed.