Solar light-driven photocatalysis has grabbed immense attention as an advanced oxidation process (AOP) to combat energy and environmental crisis in the recent past. Herein, the basic concepts of photocatalysis emphasizing their principle and history are elaborated. The semiconducting photocatalyst on light irradiation tends to generate reactive oxidative species (ROS), which are the primary driving force for the mitigation of numerous hazardous pollutants including dyes, pharmaceuticals and their metabolites, and carcinogenic heavy metal ions. The photocatalyst also demonstrates antimicrobial activity for the elimination of pathogenic microbes in wastewater. The semiconductor photocatalysts possess the potential to reduce the anthropogenic CO2 into value-added solar fuels. In addition, it offers a green approach to producing hydrogen with net zero CO2 production. The implication of the novel photocatalysts for various applications is also summarized.