Application of Exfoliated Inorganic Nanosheets for Strongly-Coupled Hybrid Photocatalysts

Inorganic 2D nanosheets are important building blocks for synthesizing efficient hybrid photocatalysts because of their advantageous characteristics such as highly anisotropic 2D morphology with subnanometer-level thickness, wide surface area, defect-free tunable surface, chemical composition diversity and crystal structure, and tailorable physicochemical properties. Since most of the components in exfoliated nanosheets are exposed on the surface, an unusually strong chemical interaction and a remarkable electronic coupling can occur in the interface between the exfoliated nanosheets and hybridized nanospecies. Such strong electronic coupling is useful in optimizing the photocatalytic activity of the hybrid material via the suppression of electron–hole recombination, increase of the light absorption region, improved transport of excited charge carriers, and increase of surface reactivity. Herein, several representative examples of inorganic 2D nanosheet-based hybrid photocatalysts are introduced to examine the crucial role of 2D nanosheets in the enhancement of the photocatalytic activity of the hybrid materials. Special emphasis is made regarding the unique hybridization effect of exfoliated 2D nanosheets on the optical properties and electron structure of semiconducting species. Future perspectives for the investigation of the 2D nanosheet-based hybrids are discussed to provide valuable insight for the design and synthesis of highly efficient photocatalysts for producing solar fuels.