The increasing demands for clean, green energy driven by urbanization and modernization while reducing atmospheric pollution are among the current biggest global challenges. Current technologies employed in the production of energy involve the burning of fossil fuels and directly impact our ecosystem, with 92% of carbon emissions emanating from such exercises. Thus, a drastic reduction in greenhouse gas (GHG) emissions around the globe is highly recommended to produce clean and green photocatalytic energy. The environment may also be impacted by water pollution from industrial effluent and volatile airborne compounds (VOCs). The implementation of these advanced technologies is a foreseeable revolutionization for energy production and purification of the environment. In addition, standard procedures and enactment for monitoring, immediate rectification, and other propitious solutions to these environmental and energy-related concerns must be the forefront of research at both institutional and industrial levels. One of such solutions is the metal-based semiconductor nanostructures for enhanced photocatalysis. These nanostructures could be exploited for their solar energy-driven redox reactions to produce green and renewable energy. Despite the reported rapid recombination of photo-excited charge carriers and slow interfacial transfer of electron-hole pairs in semiconductors, expediting the segregation of charge carriers, incorporation of noble metals, engineering of nanocomposites, and morphology modulation suppress these shortfalls. In addition, the formation of junctions inserted amidst two semiconductors can enhance the segregation of photo-excited charge carriers, resulting in homojunction- and heterojunction-based semiconductor photocatalysts. This chapter provides a comprehensive review and discussion of photocatalysis driven by metal-based nanostructures for addressing global environmental and sustainable green energy production-related challenges. Moreover, this chapter provides an overview of the mechanisms behind the photocatalytic activity of metal-based nanostructures, their potential applications, challenges, and future prospects in renewable energy, energy production, and CO2 utilization.