here is step from journal.

1. add 3g graphite powder in 70ml H2SO4. in ice bath and constant stirring.

2. add 9g KMnO4, after a while it become green

3. heat it to 40celcius for 30minutes, it became muddy brown color.

4. add 150ml water slowly

5. increase temp to 95celcius maintain until 15minute,

6. add 500ml DI water

7. add 15ml H2O2 turning color from dark brown to yellow color.

after step no7 the color still not change and i keep stirring 2hr with 90celcius unfortunately, the solution remain same.

anyone had tried the same procedure before? is there any secret recipe?