This book covers all important topics of photocatalysis in simple language with clear presentation. Nanostructures are continuously improving the functional characteristics of the material because of enhanced surface to volume ratio. Therefore, in this book a concise and balanced account of all key aspects of nanostructures-based-photocatalysis, such as kinetics, mechanism, essential factors influencing the photocatalysis, as well as its recent developments, important applications, and future prospects has been presented systematically. In addition, historical background on each topic has also been provided along with the recent development to make it interesting to read.