Theoretical Concepts of Photocatalysis offers a concisely structured and systematic overview of photocatalysis, as well as exploring the theory and experimental studies of charge carrier dynamics. Introducing the fundamental concepts of photocatalytic reactions involving different types of photocatalysts for various applications including in the treatment of water and air, in food packaging, and in the biomedical and medical fields, the detailed chemistry of visible light-induced photocatalysis, shown by different classes of photocatalysts for novel energy and environment related applications, are included. Photocatalysis using different types of photocatalysts (metal oxides, chalcogenides) is a green technology that has been widely applied for environment remediation and energy production. Its significant advantages, such as its low cost, high efficiency, harmlessness and stability is discussed alongside future perspectives and challenges of photocatalysis. Focusing on nanostructure control, synthesis methods, activity enhancement strategies, environmental applications and perspectives of semiconductor-based nanostructures, this book offers guidelines for designing new semiconductor-based photocatalysts with low cost and high efficiency to meet the demands of the efficient utilization of solar energy in the area of energy production and environment remediation.