The topic of photocatalysis is becoming increasingly important due to its essential role in many of today's environmental and energy-source problems. This book gives a comprehensive treatment of photocatalysis in three parts. The first part presents a brief introduction to the principles and fundamental aspects of photocatalysis including photoelectric chemical semiconductors. Part II describes applications to environmental cleaning, such as water purification and cleaning of the atmosphere. Part III discusses applications to photoenergy conversion, for example water decomposition with TiO2, semiconductors and metal complexes. Serving as a timely and convenient reference source including exciting new advances, the book will appeal to academic and industrial researchers as well as graduate and senior undergraduate students in the fields of photochemistry and photocatalysis.