Clean environment and green energy are the basic requirements of a sustainable human life. Semiconductor materials play a crucial role in addressing the issues related to increased global energy demand and environmental remediation. The development of photocatalysts has experienced almost exponential progress since their popularization in the early 1970s. Therefore, researchers have started to consider the diversity of photocatalysts globally by approaching this domain from a materials science perspective for applications in various areas. Recently, heterojunction photocatalytic materials have attracted a great amount of multidisciplinary research to face the global concerns of energy production and environmental protection. The unique potential of these technologies has been the stimulus to develop heterojunction photocatalysts with improved structural, morphological, and electronic properties, effectively increasing their efficiency. This book overviews the latest advances in this field, offering insights into the materials and applications of the latest generation of photocatalytic materials. It presents the challenges, future directions, and strategies for design within the area of heterojunction photocatalysts and will be a useful resource to enhance understanding of students, researchers, and academicians for promoting research in this field.