Asha Radhakrishnan - Department of Chemistry Devaswam Board Pampa College, Parumala, Pathanamthitta, Kerala, PIN ۶۸۹۶۲۶, India.
Padmavathi Rejani - Nano Science Research Lab, Department of Chemistry, D. B. College, Sasthamcotta, Kollam, Kerala, India.
Bhaskaran Beena - Nanoscience Research Lab, Department of Chemistry Devaswom Board College Sasthamcotta, Kollam, Kerala, PIN ۶۹۰۵۲۲, India.

Present work focuses on the synthesis strategies for different CuO nanostructures along with associated formation mechanisms and their interesting fundamental properties, and promising applications in biological and environmental remediation. We present a variety of synthesis techniques for producing diverse types of CuO nanostructures with various morphologies such as nanoparticles, nanoleaves, nanotubes, and nanoflowers. The effect of synthesis parameters on manipulating the nanoscale features along with the associated growth mechanisms for these unique morphologies is also discussed. The surface, electronic and optical properties of these nanostructures is also detailed. The photocatalytic and antimicrobial applications of these nanostructures are systematically introduced and summarized. Congo red and Malachite green organic dyes were degraded by these CuO nanostructures and it was found that CuO nanoflowers are more favorable for the degradation of Congo red and Malachite Green due to their higher surface sites and surface defects.  Overall, in addition to size, morphology has a significant effect on the properties and applications of nanomaterials. The synthesized novel hierarchical CuO nanostructures with large surface areas and carefully defined surfaces are best suited for treating industrial effluents.

Antimicrobial Activity, Biogenic method, CuO nanostructures, Nano photocatalyst, Photodegradation