Ag–TaN sputtered on polyester (PES) accelerated >6 times the bacterial inactivation kinetics compared to TaN–PES under actinic light irradiation. Direct current pulsed magnetron sputtering (DCP) was used to sputter Ag–TaN–PES and TaN–PES. Complete bacterial reduction by Ag–TaN occurred within 20 min compared to Ag–TiN (100 min) and Ag–ZrN (90 min). The co-sputtering of Ag and Ta on PES was carried out in an Ar/N2 10% atmosphere. By ion-coupled plasma mass-spectrometry (ICP–MS) a reduced Ag-release was observed for Ag–TaN samples compared to Ag–PES samples within the disinfection period. The redox catalysis by the Ag-species during the bacterial disinfection was followed by X-ray photoelectron spectroscopy (XPS). A bacterial reduction mechanism is suggested consistent with the experimental findings. The nitride films were characterized by surface science methods.