The photocatalytic activity of titanium dioxide (TiO2) was improved by forming a matrix containing silver (Ag) nanoparticles (NPs) prepared by a plasma process. The plasma-assisted reduction process successfully formed metallic Ag on the surface of the TiO2 NP matrix to create the Ag-TiO2 Janus heterostructure. The synthesized NPs were characterized using Brunauer, Emmett, and Teller surface analysis, transmission electron microscopy, x-ray diffraction spectroscopy, x-ray photoelectron spectroscopy, Raman spectroscopy, and UV-vis spectroscopy. Photocatalytic dye decomposition experiments revealed up to 96% methylene blue removal after 4 h of visible light irradiation, a fivefold increase in removal efficiency compared to using TiO2 NPs only.