Role of graphene in photocatalytic water splitting for hydrogen production

Abstract Hydrogen, owing to its high combustion energy and zero emission, is one of the primary candidates for potential fuel. One of the energy efficient ways to produce hydrogen fuel from renewable energy source is water splitting. Semiconducting photocatalysts are being widely used for the photocatalytic water splitting under electromagnetic irradiation. One of the serious issues associated with powder-type photocatalysts is recombination of photoexcited electron–hole pairs which in turn decrease the hydrogen fuel production. The best technique among the available strategies is use of conducting solid support material to prevent this electron–hole pair recombination. Graphene, a rising-star material, finds more attention as a conducting support for the photocatalysts due to its interesting physiochemical properties such as high electron mobility and chemical stability. Besides, the graphene tailors the bandgap energy levels of semiconducting photocatalyst, in some cases. In this book chapter, the role of graphene in photocatalytic water splitting to produce hydrogen fuel is discussed. More specifically, the influence of graphene in hindering the electron–hole pair recombination in mono- and binary semiconducting photocatalytic systems is described in detail. Similarly, the effect of graphene-based material in transferring the electron either from one semiconductor to the other semiconductor or from the semiconductor to the metal is discussed. Furthermore, effect of graphene in the noble metals, transition metals, and nonmetals doped photocatalytic systems are listed. The activity of graphene-supported photocatalyst is compared with the activity of unsupported photocatalyst. In almost all the cases, graphene-supported photocatalyst showed higher hydrogen evolution rate. Download full-size image