Table 1.

Effects of cobalt doping on the photocatalysis of ZnO nanopowders.

Doping at%	Excitation Wavelength Range	Change in Photocatalysis	Synthesis Methods	Reference
0–15	Visible light	Enhanced	Solvo-thermal	[20]
0–1.5	Visible light	Enhanced	Solvo-thermal	[21]
0–5	Visible light	Enhanced	Hydro-thermal	[22]
0–10	Visible light	Enhanced	Coprecipitation (sol-gel)	[23]
0–5	UV light	Reduced	Coprecipitation (sol-gel)	[24]
1, 10	UVC (Hg lamp)	Reduced	Coprecipitation (sol-gel)	[25]
0–9	UVA (365 nm)	Reduced	Coprecipitation (sol-gel)	[26]
0–10	UVA (365 nm)	Reduced	Coprecipitation (sol-gel)	[23]
0–10	Natural sunlight	Identical	Coprecipitation (sol-gel)	[27]
0–5	Simulated sunlight	Reduced	Coprecipitation (sol-gel)	[15]
0–5	Hg-Xe lamp	Reduced	Mechanochemical	[28]
0–5	Simulated sunlight	Reduced	Mechanochemical	[29]