. 2023 Jan 19;15(2):338. doi: 10.3390/pharmaceutics15020338

Table 3.

List of GO preparation approaches from agricultural and industrial wastes.

Year	Waste	Physico-Chemical Process and Reagents	References
Agricultural Wastes
2015	Sugarcane bagasse	Muffle furnace (T = 300 °C, t = 10 min) Ferrocene	[91]
2020	Coconut shell	Carbonization (T = 600 °C, t = 3 h) + Modified Hummers method (NaNO₃, H₂SO₄, KMnO₄)	[93]
2020	Tea	Carbonization (T = 750 °C, t = 3 h, argon) + Modified Hummers method (NaNO₃, H₂SO₄, KMnO₄)	[92]
Industrial Wastes
2018	Carbon Tyre	Crushing + Modified Hummers method (NaNO₃, H₂SO₄, KMnO₄)	[94]
2019	Toner Powder	Modified Hummers method (NaNO₃, H₂SO₄, KMnO₄)	[95]
2020	Generic	Leaching (6 M HCl, T = 70 °C, t = 210 min) + Modified Hummers method (NaNO₃, H₂SO₄, KMnO₄)	[96]