Chapter 10 - Metal organic framework-based photocatalysts for hydrogen production

Abstract

Metal-organic frameworks (MOFs) are a class of porous materials that showed interesting applications in the fields of photocatalytic hydrogen generation. The intrinsic coordination structure between the metal cluster and organic ligands offers great flexibility to tune their semiconducting property for extended and intense light harvesting. These are crystalline porous materials formed from bi- or multipodal organic linkers and transition-metal nodes. Some of them have high structural stability, combined with large flexibility in design and postsynthetic modification. MOFs can be photoresponsive through light absorption by the organic linker or the metal oxide nodes. Photoexcitation of the light absorbing units in MOFs often generates a ligand-to-metal charge carrier separation that enhanced the photocatalytic activity. In this chapter, we provide a brief introduction of the MOF materials, historical developments, and important methods for the synthesis of MOFs and then discuss the advantages and uniqueness of MOFs offered in photocatalysis. We present the best practices to determine the photocatalytic activity in MOFs and for the deposition of cocatalysts. In particular, we give examples showing the photocatalytic activity of MOFs in H2 evolution. The schematic representation of applications of MOFs as sensitizer and cocatalysts is shown in the scheme 10.1.