Graphene has become one of the most important materials of
the 21st century and there exists a huge variety of methods for making it. Quite a few of these are well out of the reach of the average small lab, independent researcher, inventor and experimenter. However many of them are quite approachable and have been demonstrated in my videos on youtube

https://www.youtube.com/user/RobertMurraySmith

you can also find me at

fwgltd.co.uk/

Mostly, people have been interested in producing graphene and a lot of the methods get you straight there. However, initially, the best way of making large amounts of graphene was through a wet chemical method that first made graphene oxide and from that you went back to graphene. As better and better methods were developed for getting straight to graphene developed the wet chemical methods fell behind as they were dangerous, expensive and needed practice to get right.

But, graphene oxide as a material in itself is well worth looking and and shouldn’t be abandoned in the rush for graphene.

One of the best ways of producing large amounts of graphene oxide via a wet chemical method is by the so-called ‘Tour’ method, which is an adaptation of the Hummer’s method.

The Method in this guide is from the paper ‘Improved Synthesis of Graphene Oxide’ that appeared in ACSNano in July 2010. In the month that it appeared it was one of the most downloaded of all scientific papers.

The method is really very simple, but if you are going to try it you will need a heated stirrer as you have to stir the mix at 50 degrees centigrade for 12 hours and nobody wants to do that by hand!

Step 1: What Do You Need?

For something like this you need to get the good stuff. Although you can use hardware store items the results are never going to be as good as if you buy a few items of high grade materials. For the graphite you will need flake graphite powder – you can try ground up pencils but you are likely to be disappointed – the powder size can vary from 5 microns to 150 microns. The particle size will affect the end product and what it is good to use for. For example the small sizes will inkjet print but the will be less conductive than the larger particle – every thing is a trade off.However - the materials can be easily found at the hardware store and the names are in brackets after the chemical name.

Materials

3 grams of Graphite ( a 9B pencil from the art store)

18 grams of Potassium Permanganate (from the chemists - drug store -it's an antiseptic)

360 mL of 96% Sulphuric Acid (One-Shot drain cleaner)

40mL of 75% Phosphoric Acid (this is a food additive - you will have to order this online)

400mL of De-Ionised Water (Battery top-up water)

3mL of 30-35% Hydrogen Peroxide (hair bleach, teeth whitener)

Equipment

A Heater Stirrer

2 Beakers – 1 x 1L and 1x500mL

A Large Glass Container (a 2L Jug)

A glass Stirring Rod

A pipette able to measure 3mL

Safety Equipment

Gloves

Glasses

For Washing

200mL Water

200mL Ethanol (Bioethanol fuel)

200mL 30% Hydrochloric Acid (Muriatic acid or Spirit of salts)

Step 2: The Procedure

Making the Graphene Oxide is extraordinarily easy. The real
problem arises because this uses strong acids and the temperature should not be allowed to go over 55 degrees centigrade.

1) Mix the 3g of graphite and 18 grams of potassium permanganate (a 1:6 ratio by weight) together in the 1 Liter beaker ensuring an even mix.

2) Add 360mL of 96% sulphuric acid to the 500mL beaker, then add 40mL of 75% phosphoric acid (a 6:1 ratio)– the mixture will get a little warm – wear gloves and glasses

3) Stir the graphite and permanganate mix with one hand and add the acid mix to with the other stirring all the while.

4) Stir until mixed

5) Place on the heater stirrer and stir at 50 degrees centigrade for 12 hours

6) Allow to cool to room temperature

7) Make ice from around 400mL of de-ionised water

8) Add the ice to the large glass container

9) Pour the graphite acid mix over the ice into the large glass container

10) Add 3mL of 30% hydrogen peroxide to mixture and stir

Congratulations – you now have a jar full of graphene oxide. The next thing you need to do is clean it.