This book covers the basic concepts and applications of photoredox processes. This book highlights the applications of photoredox reactions in waste management, photoremediation, photodeposition, photocatalysis, sustainable therapeutic approaches, natural product synthesis and derivatization to photocatalytic degradation and beyond. The challenges associated with the application of synthetic transformations are the hazardous economic reaction conditions. It further discusses the application of these mechanisms in drug derivatization and degradation. The book also covers the topic of nano-photocatalyst for drug-free therapeutics. This book is useful for researchers and professionals in the various areas of applied chemistry and biotechnology and allied fields.