Two-dimensional nanomaterials as photocatalysts for solar-driven production of chemicals

Abstract

The utilisation of renewable solar energy shows great potential in tackling the problem of increasing carbon emission due to the combustion of traditional fossil fuels. To achieve carbon neutrality, more efforts need to be made on the exploration of efficient conversion of solar energy into chemical fuels/feedstocks. Particularly, chemical fuels with high energy density are ideal for storage and transportation. For the efficient transformation of solar energy into chemical fuels, high-performance photocatalysts are required to facilitate this process. Therefore, this thesis aims to find out a universal strategy for designing and fabricating novel nanomaterials as efficient photocatalysts for photocatalytic reactions. Besides, photocatalysts for emerging reactions fabricated via advanced delicate techniques and demonstrated for widespread applications are also reviewed and discussed comprehensively. Thanks to the ultrathin layered structure and exposed uncoordinated atoms, the exposed edges of 2D nanomaterials have shown great potential in acting as reactive sites for various photocatalytic reactions. In this thesis, two-dimensional Co-MOF, Ni-MOF and FePS3 (discussed in chapters 3-5) have been introduced to cooperate with the main photocatalysts for hydrogen evolution and it turns out that they have significantly improved the initial catalytic performances of the counterparts without them. These twodimensional nanomaterials play key roles in improving the photocatalytic activity of the main photocatalyst by providing sufficient reactive sites and facilitating charge separation/transfer. Also, the recent research progress of solar-driven simultaneous production of hydrogen and value-added chemicals (chapter 2), and the single-atom-based photocatalysts for emerging reactions (chapter 6) have been reviewed and discussed in this thesis. The combination of searching for high-performance photocatalysts and adapting for emerging reactions will promote the transformation and utilisation of solar energy. Probing into the origin of the structure-performance relationship and finding out a universal strategy for designing and screening outstanding high-performance photocatalysts for various reactions is of great importance for research on solar energy transformation. Meanwhile, finding approaches to improving solar-driven reaction efficiency will be of great benefit to the development of the solar energy industry as well.