Preparation, characterization and photocatalytic activity of metalloporphyrins-modified TiO_2 composites

摘要

Three new Cu(II), Zn(II), Co(II) 5,15-di (4-hydroxyphenyl)-10, 20-diphenyl-porphyrin (CuDHPP, ZnDHPP, CoDHPP) and the corresponding metalloporphyrins-TiO2 photocatalysts CuDHPP-TiO_2, ZnDHPP-TiO_2, CoDHPP-TiO_2 were synthesized and characterized by SEM, XRD, FT-IR, and DRS. The results revealed that the metalloporphyrins impregnated onto the surface of TiO_2 did not change the phase composition and particle sizes of TiO_2 samples, but increased the photocatalytic efficiency. In addition, photoluminescence study showed that the three photocatalysts could successfully increase the separation efficiency of the photoinduced electron and hole. The photodegrading 4-NP experiments indicated that the three photocatalysts greatly enhanced the photocatalytic activity of bare TiO_2, and the photocatalytic activity of CuDHPP-TiO_2 was the highest. Moreover, the possible mechanism for the photodegradation of 4-NP was also proposed.