<p>Multijunction composites of Ag-decorated anatase-/rutile-TiO₂ (Ag/A-/R-TiO₂) heterostructures were synthesized for efficient visible-light-driven photodegradation and disinfection. The A-TiO₂ layer was spin-coated onto the hydrothermally grown R-TiO₂ nanorod array films, followed by decoration with Ag nanoparticles via chemical reduction on the A-/R-TiO₂ surface. The crystalline phases, morphologies, microstructures, and optical properties of the prepared samples were investigated. The composite after forming gas annealing (Ag/A-/R-TiO₂–FGA) exhibited outstanding photodegradation performance, achieving 100% degradation of Rhodamine B in 80&#xa0;min under visible-light irradiation. The sample also exhibited promising antibacterial performance, with approximately 82% of bacteriophage MS2 disinfected in 40&#xa0;min under visible-light irradiation. Energy band structures were constructed to elucidate these superior activities, which were synergistically caused by improved visible-light absorption owing to multiple light scattering in the R-TiO₂ nanorod arrays, localized surface plasmon resonance induced by the reduced oxidation of the Ag nanoparticles, and charge carrier transport facilitated by the formation of multi-heterojunctions and a dye-sensitized process. Our results highlight the potential of the Ag/A-/R-TiO₂ composite for practical environmental applications under visible light illumination.</p> Graphical Abstract <p></p>