*4.1.1. Effect of visible light intensity*

Photocatalytic inactivation reactions are highly dependent on the irradiation intensity of the light source [34, 63]. The increase in the visible light intensity from 2 to 8 W.m<sup>2</sup> can enhance the bacterial inactivation over TiO2 -AgNP photocatalysts. The observed enhancement in the inactivation is due to the increase in the number of photons produced as light intensity rise.
