The gaseous MoO2Cl2 was subsequently guided to the carbon cloth substrate, promoting the growth of MoOxCy within the highly reductive hydrogen plasma environment. Meanwhile, the surface of carbon fiber substrates was etched by hydrogen plasma, generating hydrocarbon species that served as the carbon source for MoOxCy formation. Moreover, the presence of a strong electric field in the plasma sheath can guide the growth of materials in a vertical orientation to the substrate . As shown in Figure , the PECVD-grown HP-MoOC exhibits unique petal-like structures, with MoOxCy nanosheets aligned roughly perpendicularly to the substrate, exhibiting high aspect ratios and abundant exposed ultrasharp nanoedges. The thickness of the nanosheets is only a few nanometers (Supplementary Figure ). Such morphology distinctly differs from the particle-or flat sheet-like transition metal oxides that are grown by conventional thermal chemical vapor deposition reported in prior studies .