**5. Conclusions and outlooks**

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 to anchor organic conjugated aromatic molecules and their applications in photo-energy conversion and photocatalysis.

However, despite many successful examples showing that photoactive graphene holds excellent properties and great potentials in various applications, there are still some problems that need to be overcome. One major drawback for the use of photoactive graphene in photoenergy conversion and photocatalystic application is light absorption without directly generating long-lived charge carriers.[21] Hence, one needs to take caution in optimizing the modification degree of photoactive moieties functionalized to graphene surface. Moreover, optimization of the charge carriers transfer channel of photoactive graphene, as well as precisely controlling any combination of direction, position, and distance of graphene and photoactive molecules are also necessary for high-efficiency photo-energy conversion appli‐ cation. More careful design of the chemical functionalization is necessary to exploit the electronic properties of graphene and photoactive groups, for example, multifunctional graphene materials with different moieties can provide new ways to design charge-transfer systems for light energy conversion.

From another point of view, chemists will be needed to develop strategies for rational design and facial synthesis of photoactive moiety; not only morphology and electronic structure, but also redox properties are also important for tuning the charge-transfer process of photoactive graphene, because the more precisely manipulated the charge-transfer efficiency of photoac‐ tive moiety–graphene interfaces, the more favorable it is to improve the photo-electron conversion efficiency and photocatalytic performance. With more progresses in the material optimization and novel device design, we believe that photoactive graphene will lead to a wide range of applications.

Finally, the photoactive graphene researches are still at their initial stages. With the multidis‐ ciplinary efforts from chemistry, physics, and materials science, we believe that much more progresses in the applications of photoactive graphene will become a reality in the near future.
