Hydrogen produced from photocatalytic water splitting offers a promising clean energy solution to address the environmental crisis and meet global energy demands. By carefully selecting materials with complementary band structures, heterostructures can create a built-in electric field that promotes charge carrier migration, thereby enhancing hydrogen evolution efficiency. Integrating heterostructures, plasmonics, and quantum dots significantly advances photocatalytic hydrogen production. This chapter focuses on innovations in heterostructures, plasmonics, and quantum dots, discussing their potential to advance photocatalytic hydrogen evolution. It provides a brief overview of recent research contributions to sustainable energy solutions. It describes the latest developments in composites/heterostructures, plasmonic nanomaterials, and quantum dot-based photocatalysts for hydrogen evolution reactions. The beneficial impact of these materials, due to the formation of diverse heterojunctions that promote electron–hole separation and enhance catalytic performance, is also discussed. The chapter examines the efficiency of photocatalytic behaviors in energy conversion applications and offers strategies for designing semiconductor architectures using plasmonic and quantum dot heterostructures for photocatalytic water splitting. Future research directions to optimize these advanced materials for higher efficiency and stability in photocatalytic systems are outlined, and the prospects for semiconductor heterojunction and quantum dot photocatalysts are proposed.