**Author details**

reactions. For example, in Figure 8, photoactive graphene of noncovalently bonded graphene– polymer (P3HT) composite shows significant advancement of photocatalystic performance in Mannich reaction over commercial photocatalyst P25 (Loh *et al*., 2012).[100] Transient optical absorption studies have inferred that the tertiary amine is oxidized by the positive hole on the highest occupied molecular orbital (HOMO) of P3HT *via* single electron transfer to form the radical cation. At the same time, the excited electron is injected from the lowest unoccupied molecular orbital (LUMO) of P3HT into GO, which is then used to activate molecular oxygen to form the dioxygen radical anion; the latter can be stabilized by the aromatic scaffold in GO. [93] Pan *et al.* found that incorporation of Rose Bengal (RB) with GO sheet can provide higher catalyst actively of the visible light induced oxidative C-H functionalization of tertiary amines,

**Figure 8.** GO/P3HT composite as a synergistic photocatalyst (Loh *et al*., *J. Phys. Chem. Lett.* 2012, *3*, 2332-2336).

This chapter presented some important features of photoactive graphene, from material synthesis, electron/energy-transfer interaction to organic photovoltaic and photocatalystic applications. Of particular interest is the utilization of graphene as a two-dimensional platform

even there was no direct physical interactions between RB and GO.[101]

**5. Conclusions and outlooks**

104 Graphene - New Trends and Developments

Hang-Xing Wang1,2 and Hao-Li Zhang1

1 Lanzhou University, Lanzhou, China

2 Hubei University, Wuhan, China
