The in-depth usage of organic pollutants by pharmaceutical industries constitutes a major contaminant to the bodies of water due to their solubility, great mobility, ability to get attached to water bodies for a long period of time, and low biodegradability. Due to these, it may further cause disease and change the ecosystem of aqueous and other living organisms. Accordingly, effective removal of organic contaminants from waste water is a vital step in reducing the hazards. Photocatalysis is a potential technique for removing hazardous organic pollutants from wastewater. In this work, a simple ultra-sonication assisted approach, a series of Carrisa edulis fruit extract capped Co3O4 nanoparticles decorated on Montmorillonite K30 nanosheets (Co3O4/MK30) were prepared. The inherent physicochemical appearance and optical properties of as-prepared nanomaterials were investigated using a variety of analytical techniques. TEM analysis depicted the spherical shape of the Co3O4 NPs with the size of 11.25 nm. The degradation of methylthioninium chloride as a dye and tetracycline drug pollutants has been investigated in this study using individual and simultaneous photocatalysis systems in the presence of pure Co3O4 NPs and different ratios of Co3O4/MK30 nanocomposites. Owing to the generation of OH and O2 radicals, the 20% loaded Co3O4 on MK30 had the best photocatalytic performance of methylthioninium chloride (98.12%) and tetracycline degradation (87.4%), on exposing it to visible light. This research introduces a new design for MK30-based nanomaterials and proposes its use in environmental challenges.