The present invention relates to a photocatalytic material having a visible light activity which includes a tungsten-doped titanium oxide or a tungstengallium-codoped titanium oxide, and a divalent copper salt andor a trivalent iron salt supported on a surface of the doped or codoped titanium oxide, and a process for producing the photocatalytic material. Each assembly includes a flexible cover that can be operatively secured to side rails. Pairs of current conductors emanate from the discharge vessel. , and having disrupted base pairing between the virus’ 5\u2032 and 3\u2032 cyclization sequences.