In this present study, the multidisciplinary p-type Cobalt oxide (Co3O4) nanoparticles has been synthesized via green route utilising Citrus Medica L. extract at various concentration. The biomolecular effects on the Co3O4's physiochemical properties has been examined. In the case of XRD investigation, the nanoparticle's size and growth was considerably assisted by phenolic - Flavonoids metabolites. Results suggested the formation of 8.3 nm sized nanocrystals with good crystallinity. The surface capped biomolecules signatures on Co-O has been unveiled through vibrational investigation. Optical bandgap of the nanoparticle possesses a favorable energy level gap, allowing it to function well under visible spectrum with good water splitting potential. The morphological analysis exhibits the particle formation at different structures, a spherical disc structured were obtained by 30 mL of biomolecular preparation. Further the synthesized nanoparticles examined under XPS reveals the existence of cobalt and oxygen chemical state. The optimal degradation efficiency of ∼ 96% and 94% for Methylene Orange (MO) and Methylene Violet (MV) was achieved within a time period 60 min under solar light irradiation. Therefore, the synthesized Co3O4 NPs can be employed for various applications, specifically for the remediation of wastewater contaminated with dyes.