Semiconductors have emerged as a promising solution to environmental problems, such as environmental remediation, water purification, and renewable energy generation. However, traditional semiconductor synthesis often involves the use of toxic chemicals, energy-intensive processes, and unsustainable methods, which contradicts the principle of green innovation. This chapter explores the application of green synthesis techniques in semiconductor fabrication for photocatalysis, emphasizing sustainable methodologies that minimize environmental impact. Solventless synthesis, the use of biodegradable and renewable precursors, bio-assisted manufacturing using plant extracts or microorganisms, and energy-efficient processes: These approaches enable the creation of high-performance photocatalysts, respecting the principles of green chemistry. In addition, the role of green synthesis in improving nanomaterial properties, such as surface area, bandgap energy, and photocatalytic efficiency. The chapter also discusses the applications of green synthesis semiconductors in water splitting, CO2 reduction, and pollutant degradation, highlighting recent advances and case studies. Challenges related to semiconductor reproducibility and stability are addressed. This chapter highlights the importance of sustainable practices for advancing semiconductor-based photocatalysis and achieving a cleaner, greener future.