Department of Chemical Engineering, Dr. B. R. Ambedkar National Institute of Technology, Jalandhar-144 011, Punjab, India E-mail: gargs@nitj.ac.in Manuscript received online 03 December 2019, revised and accepted 27 December 2019 In the present study, Cu2O nanoparticles has been synthesized from Tabernaemontana divaricate leaves extract and were analyzed using various characterization techniques UV-Vis, FT-IR and AFM. FT-IR spectra displayed the presence of protein/ enzymes along with the aromatics in the spectra of Cu2O NPs that revealed the formation of Cu2O NPs from plant mediated biosynthesis. The catalytic activity of Cu2O nanoparticles was further investigated in a batch photocatalytic reactor for the degradation of 4-amino pyridine using an artificial light source. Under an optimum conditions of initial solution pH: 3, catalyst dose: 0.8 g/L and initial 4-amino pyridine concentration: 5 mg/L, the Cu2O NPs showed 80% degradation and 82% mineralization of 4-amino pyridine.