Photocatalytic Composite Materials Based on Graphene and Titanium Oxide Prepared by Different Methods

Titanium(IV) oxide graphene [1] or graphene oxide nano composite [2] were prepared by one-pot thermal hydrolysis of suspension graphene or graphene oxide nanosheets and titanium oxide in three different forms as a starting materials. Graphene nanosheets were produced in a large quantity from natural graphite using a high intensity cavitation field in a pressurized ultrasonic reactor [3]. The graphene oxide was prepared by improved Hummers method [4]. The direct interaction between TiO2 nanoparticles and graphene sheet prevents the re-agregation of the exfoliated sheets of graphene. Graphene and even graphene oxide has the ability to locally reduce the titanium to active form of Ti3+ ion. The grapheme nanosheets make Ti3+ ions stable in the TiO2 matrix and form a heterojunction system with titania.