Table 2.

Defect-rich catalysts prepared by a plasma technique.

Types of Catalyst	Types of Plasma	Characteristics	Remarks	Applications	References
Multi-wall CNTs	DBD plasma O2	Generate oxygen-containing group	The BET specific surface area: 156 m2/g	Surface modification	[50]
Graphite	DBD plasma air	Create novel defects	Protrusions 1−5 nm in diameter and smooth depressions 5−7 nm wide	Modification of graphite surfaces	[51]
Co3O4 nanosheets	Plasma-engraved Ar	With high surface area and oxygen vacancies	The BET specific surface area: 160.26 m2/g	OER	[52]
Ag catalysts	Plasma-activated H2, Ar & O2	Lower overpotential	Pore-like defects 50−100 nm in size	Carbon dioxide electroreduction	[53]
Ar-TiO2	DBD plasma Ar	Oxygen vacancies and Ti3+ defects	The energy band gap reduction	Photocatalytic degradation of organic dyes	[54]
Teflon films	DBD H2O	Point electrode		Prevent degradation and erosion	[55]