Photocatalysis: Basic Principles, Diverse Forms of Implementations and Emerging Scientific Opportunities

Photocatalysis promises a solution to challenges associated with the intermittent nature of sunlight which is considered as renewable and ultimate energy source to power activities on Earth. This review aims to provide a broad overview of the field. Insight into natural photosynthesis is discussed first, which provides a scientific basis for most efforts on photocatalysis. Afterwards, the details of four existing types of photocatalysis are presented, namely photosynthesis by plants, photosynthesis by microalgae, photocatalysis by suspension and photoelectrocatalysis. Detailed analyses of simple photocatalysts and integrated photocatalytic systems are followed to shed light on the different functionalities of different components in a working photocatalyst. Special attention is given to the roles played by surface and interface chemical phenomena. Lastly, perspectives on artificial photosynthesis are discussed briefly at the end.