Silver-doped zinc oxide nanoparticles (NPs) were synthesized employing a facile hydrothermal method supported by the seaweed Turbinaria ornata (TO). TO extract was used as a capping agent. The prepared NPs were accounted for using instrumentational analysis such as FE-SEM, EDS, XRD, FTIR, and UV-Vis. Their characteristic study showed an average size of 26 nm with 81% crystallinity with X-ray Diffraction and the band-gap value as 3.25 eV. The biosynthesized doped particle exhibited rod-shaped morphology for better efficiency in dye degradation of Methylene Blue (MB) dye. They were also tested for adsorption kinetics and photocatalytic degradation of MB using sunlight. The efficiency in degrading the MB dye proclaimed a remarkable change in solar irradiation of about 90% reduction to visible light, which leads to the betterment in solar degradation of dye pollutants at a minimal cost.