Table 2. Methods of Preparation of Graphene Oxide (GO).

S. no.	Method	Oxidant	Reaction time	Temp. (°C)	Refs
1	Brodie 1859	KClO3, HNO3	3–4 days	60	(47)
2	Staudenmaier 1898	KClO3, HNO3, H2SO4	96 h	rt	(48)
3	Hummers 1958	KMnO4, H2SO4, NaNO3	<2 h	20–35–98	(49)
4	Su 2009	KMnO4, H2SO4	<2 h	rt	(51)
5	Shen 2009	Benzoylperoxide	4 h	110	(52)
6	Sun 2013	KMnO4, H2SO4,	10 min	RT	(53)
7	Eigler 2013	KMnO4, H2SO4, NaNO3	1.5 h	10	(54)
8	Panwar 2015	KMnO4, H2SO4, H3PO3, HNO3	16 h	50	(55)
9	Chen 2015	KMnO4, H2SO4,	3 h	20–40–95	(56)
10	Dimiev 2016	(NH4)2S2O8, H2SO4	<1 h	rt	(57)