Table 2.

A brief comparison between conventional edges and two kinds of atypical edges

	Conventional edges of nanostructures	Nanoframe	Ultrathin nanowire
Structural feature	Natural ends of surfaces in nanostructures	Structures with internal atoms on surfaces and in body of particles etched out and atoms on edges reserved	Ultrathin one dimensional materials
Chemical feature		Low CN and large edge content	Low CN (maybe)
Advantage	Easy accessible and abundant types	High activity and low use of costly materials	Enhanced activity
Limits		Difficulty in fabrication; Not all NFs are stable	Dimness in detailing structures