Table 4.

List of the advantages and disadvantages of different synthesis methods for graphite oxide. Data source: [71].

Method	Oxidants	Toxicity	Advantages	Disadvantages
Brodie Method	KClO3, HNO3	Yes	-	Weak acidity. Soft dispersibility in basic solutions. Small size, limiting thickness and providing an imperfect structure.
Staudenmaier Method	KClO3 (NaClO3), HNO3, H2SO4	Yes	-	Time-consuming and dangerous method. Addition of KClO3 generally takes longer than a week and CO2 is evolved, thus making necessary to remove an inert gas. The risk of explosions is a constant danger.
Hummers Method	KMnO4, H2SO4, NaNO3	No (NOx is released)	Higher oxidation degree than that obtained in Brodie or Staudenmaier Methods.	It is still considered than the oxidation is incomplete. Separation and purification processes are tedious process. Highly time-consuming process.
Modified Hummers Method	KMnO4, H2SO4, NaNO3, KMnO4, H2SO4	No (NOx is released)	Improved level of oxidation and, therefore, product performance.	Separation and purification processes are tedious process. Highly time-consuming process.
Improved Hummers Method	KMnO4, H2SO4, H3PO4	No	Defects in the basal plane are reduced. Larger amount of oxidized graphite is provided. The degree of reduction provides an equivalent level of conductivity when compared to other methods. Best process yield compared to Brodie, Staudenmaier and Hummers method. Environmentally friendly, toxic gases are not generated during the preparation. The product has a more organized structure compared to graphite oxide obtained by Brodie and Staudenmaier methods.	Separation and purification processes are tedious process. Highly time-consuming process.