We report a biogenic method for the design and characterization of three different composite nanomaterials, CuxO/ZnO, Ag@CuxO/ZnO, and Au@CuxO/ZnO (x = I and II), with the surface plasmon resonance (SPR) effect and p-n heterojunction for photocatalysis. The crystal structure of the material was scrutinized by XRD, DRS, PL, XPS, FT-IR, EDS, and TEM analysis. To make the composite efficient, we have sensibly introduced plasmonic Ag and Au on CuxO/ZnO individually by using Ziziphus jujuba leaf extract. The widened light incorporation, effectual conveyance of photogenerated carriers, and incidence of brawny SPR effect makes the composites sensitive under visible light. The synthesized ternary composites, Ag@CuxO/ZnO and Au@CuxO/ZnO, exhibit much higher photocatalytic activity than ZnO and CuxO/ZnO for the degradation of industrial textile effluent and methyl orange under sunlight as well as UV light. Using effortless comet assay practice, the genotoxicity of TE prior to and past photodegradation was assessed.