Enhanced photocatalytic activity of nitrogen doped TiO2 photocatalysts sensitized by metallo Co, Ni-porphyrins

► Four kinds of metalloporphyrin sensitized nitrogen-doped titanium dioxide composites have been prepared successfully. ► Four composites as photocatalysts have been investigated and contrasted for the first time. ► The mechanisms of higher degradation efficiency for cobalt porphyrins sentisized N-TiO2 are reduced.