Here, an unprecedented synthesis method for nickel oxide nanoparticles (NiO-NPs) was facilitated using Salvia hispanica leaf extracts with the assistance of a high gravity rotating packed bed (RPB) system that enabled fast mass transfer and molecular mixing. The synthesized nanoparticles were anchored on the surface of biodegradable chitosan nanobeads and their photocatalytic activity was evaluated by the degradation of methylene blue. Additionally, the potential biological activities of NiO-NPs in terms of antibacterial (Staphylococcus aureus and Escherichia coli for 24 hours), cytotoxicity (using the PC12 cell line for 24 and 72 hours), and antioxidant activities (based on the discoloration of the methanolic solution of DPPH) were assessed. This novel approach for NiO-NPs@Chitosan synthesis as mediated by a renewable plant extract and facilitated by a high-gravity method, led to the greener synthesis of nanoparticles with significant antibacterial and photocatalytic properties.