Enhanced photocatalytic disinfection of Escherichia coli bacteria under visible light illumination was achieved by introducing silver and nickel comodification onto a nitrogen-doped titanium oxide nanoparticle photocatalyst synthesized by the sol-gel process. The introduction of a small amount of the second-type transitional metal ion addition is demonstrated as an effective approach to further enhance the optical and photocatalytic properties of single-type transitional metal ion modified anion-doped titanium oxide photocatalysts.