Sensitization of TiO2 with novel Cu(II) and Ni(II) polyaza complexes: Evaluation of its photocatalytic activity

The semiconductor TiO2 was sensitized by the incorporation of novel Cu(II) and Ni(II) polyaza complexes. The complexes were prepared with two different polyaza macroligands: N1-(2-aminobenzyl)-N2,N2-bis(2-((2-aminobenzyl)amino)ethyl)ethane-1,2-diamine and N1-(2-aminobenzylidene)-N2-(2-((2-aminobenzylidene)amino)ethyl)-N2-(2-(-(2-aminobenzylidene)amino)ethyl)ethane-1,2-diamine. Both the Ni(II) and Cu(II) complexes and their modified TiO2 catalysts were characterized by elemental and spectral analyses (FTIR and UV-vis reflectance diffuse spectroscopy). The photocatalytic activity of the prepared catalysts was tested under visible radiation for the degradation of phenol in aqueous solution. The results showed that the incorporation of these complexes improves the activation of TiO2 with visible light; however, the Ni(II) polyaza complex with the N1-(2-aminobenzylidene)-N2-(2-((2-aminobenzylidene)amino)ethyl)-N2-(2-(-(2-aminobenzylidene)amino)ethyl)ethane-1,2-diamine macroligand enhanced the photocatalytic performance of TiO2, thereby making it suitable for application in heterogeneous photocatalysis using visible light as the energy source.