Theoretical Concepts of Photocatalysis offers a systematic overview of photocatalysis while also 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 the treatment of water and air, in food packaging, and in the biomedical and medical fields, the book shows different classes of photocatalysts for novel energy and environmental related applications. In addition, significant advantages, such as its low cost, high efficiency, harmlessness and stability are discussed alongside future perspectives and challenges related to 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.