Yogyakarta — A student team from Universitas Negeri Yogyakarta (UNY), through the 2026 Student Creativity Program for Exact Science Research (PKM-RE), is developing a Cu₂O/CuO@TiO₂ nanocomposite based on copper cable waste using key lime peel extract as a green synthesis approach. The research aims to develop a photocatalytic material that can be utilized for the photodegradation of batik dye wastewater.