Green Synthesis of Cobalt Oxide (Co ₃ O ₄ ) Nanoparticles Using Caulokaempferia Secunda Root Extracts

ABSTRACT

The aim of this work is to use the root of Caulokaempferia secunda (Wall.) K. Larsen to biosynthesize cobalt oxide (Co ₃ O ₄ ) nanoparticles (NPs). The evaluation of the synthesized NPs was carried out by using various standard techniques. The characterization results established the successful synthesis, structural reliability, functional properties, and nanoscale size of the nanoparticles. The synthesized Co ₃ O ₄ NPs were employed to assess free radical scavenging activity using 1,1‐diphenyl‐2‐picryl‐hydrazyl (DPPH) and their antimicrobial potential against Gram‐positive and Gram‐negative bacteria. The electrochemical investigation of the Co ₃ O ₄ NPs was performed using cyclic voltammetry. The nanoparticles exhibited admirable antibacterial activity against the four tested microorganisms. The DPPH free radical scavenging activity of Co ₃ O ₄ NPs ranged from 21.62% to 72.29%, indicating a notable capacity to neutralize free radicals and demonstrating significant antioxidant activity. Furthermore, cyclic voltammetry analyses reveal that the synthesized Co ₃ O ₄ displays hysteresis in its cathodic and anodic peak potentials, which ranged from −0.1 to +0.1 V. The findings of this study suggest that green‐synthesized Co ₃ O ₄ NPs containing C. secunda root extract could be utilized in biomedicine, supercapacitors, and as a substitute for biological and electrochemical applications. The nanoparticles that are synthesized exhibit promising antibacterial, antioxidant, and electrochemical properties, highlighting their potential.