Years of ever-increasing demand for environmental sustainability have been forcing significant research progress in the development of next-generation green nanomaterials, specifically in photocatalysis. Ranging from resolving serious challenges in the environment, the nanomaterials, designed to efficiently harvest solar energy, can solve problems of water purification, reduction of carbon dioxide, and generation of solar hydrogen. With the growing concern over climate change and pollution, the time has never been so crucial for technologies that can reduce harm to the environment while finding sustainable energy solutions. It discusses new developments in the field of green photocatalytic nanomaterials, with a focus on fresh design approaches that aim to make solar energy conversion more effective using these photocatalysts. Such advances, of course, are crucial for optimizing photocatalysts for particular applications. The design of both the materials themselves and their accompanying synthesis and application systems must be oriented toward sustainability so they contribute to water decontamination and reductions in greenhouse gas emissions while minimizing environmental impacts. In addition, the chapter highlights the most crucial challenges in scaling up the production of materials under focus and integrating them into practical applications. The large-scale production needs to be ensured not to undermine environmental advantages. Finally, the next-generation photocatalysts are envisioned as advanced nanotechnology shaped by green chemistry principles, offering a clean route toward sustainable environmental solutions that bring the planet closer to global ambitions toward a cleaner, greener future.