Biogenic synthesis of nanoparticles is a chemical free, environment-friendly, non toxic and sustainable approach. This green route for nanoparticle synthesis plays a pivotal role in reducing the deteriorating effects of the conventional chemical methods of nanomaterial synthesis. The present investigation demonstrates the one-pot, rapid, green synthesis of bio-entity capped copper oxide nanoparticles using Terminalia Chebula kernels as a bio-reducing agent and study of its antimicrobial properties and effect on the photocatalytic degradation of methylene blue dye which is found in effluents and is a major cause for environmental problems. The XRD results confirmed the formation of monoclinic crystalline copper oxide nanoparticles with an average crystallite size of 20nm. The UV Visible spectroscopic studies showed characteristic absorption peak of copper oxide nanoparticles between 250-300nm. Fourier transform infrared spectroscopy and thermo gravimetric analysis confirmed the presence of tannins from seed extract. Scanning electron microscopic images confirmed the formation of spherical nanoparticles. The antimicrobial activity of biogenic copper oxide nanoparticles increased with increase in their concentrations against E.Coli and Staphylococcus aureus. Furthermore, the photocatalytic activity of the biogenic copper oxide nanoparticles showed 98% degradation of the dye under direct sunlight irradiation for 150 minutes which could a very efficient and cost –effective bioremediation as well. This article reports the role of biofunctionalized copper oxide nanoparticles in exhibiting a synergistic efficacy on the biological and photocatalytic activity leading to better bioremediation results in water treatment methods. In line with the presented comprehensive results , the biofunctionalized copper nanoparticles from T. Chebula have the potential in improving the biological and photocatylic activity owing to the presence of surface capped biomoleculaes synergistical complementing the copper oxide nanoparticles in its biological and photocatalytic activity.