OICC Press Journal of Nanostructure in Chemistry 2193-8865 11 3 (September 2021) 2021 01 04 Nitrogenated-carbon nanoelectrocatalyst advertently processed from bio-waste of Allium sativum for oxygen reduction reaction 10.1007/s40097-020-00370-w EN Pandiyaraj Kanagavalli Electrodics and Electrocatalysis Division, CSIR-Central Electrochemical Research Institute (CECRI), Karaikudi, Tamil Nadu, 630 003, IN Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, IN Gaurav R. Pandey Electrodics and Electrocatalysis Division, CSIR-Central Electrochemical Research Institute (CECRI), Karaikudi, Tamil Nadu, 630 003, IN Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, IN Vinay S. Bhat Centre for Nano Materials and Displays, B.M.S. College of Engineering, Bengaluru, Karnataka, 560 019, IN Murugan Veerapandian Electrodics and Electrocatalysis Division, CSIR-Central Electrochemical Research Institute (CECRI), Karaikudi, Tamil Nadu, 630 003, IN Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, IN Gurumurthy Hegde Centre for Nano Materials and Displays, B.M.S. College of Engineering, Bengaluru, Karnataka, 560 019, IN Journal Article 2021 01 04 Abstract Development of metal-free electrocatalyst recycled from waste is highly beneficial for environment-friendly application. Effective oxygen reduction reaction (ORR) relies on physico-chemical properties of electrocatalyst. Herein, the present report demonstrates the ORR studies of metal-free carbon nanoelectrocatalyst processed from biomass of Allium sativum . Carbon nanoparticles (CNPs) with various nitrogenation have been achieved by tuning the pyrolytic condition (400–1000 °C), using single bio-resource without additional dopants/activators. Under optimal condition, CNPs processed from 800 °C exhibit superior oxygen reduction function in alkaline medium with a Tafel slope value of 81 mV/dec, suggesting that the co-existence of nitrogen species improved the oxygen reduction active sites. Spectroscopic studies reveal that the inherent nitrogenation enriched the defects with mesoporosity in the graphitic carbon network synergizing the interfacial electron diffusion. Biomass-derived CNPs enable altered chemical species under different pyrolytic conditions suitable for cost-efficient, scalable, and sustainable ORR application. Graphic abstract .