Synthesis of novel panchromatic porphyrin-squaraine dye and application towards TiO2 combined photocatalysis

Here with, a porphyrin-squaraine-based panchromatic sensitizer was designed, synthesized perfectly and confirmed by its spectral analysis. SP-TBU showed a wide energy absorption in the visible and NIR region, which is very important criteria for photocatalytic activity studies. With this dye, a new TiO2-porphyrin catalyst was prepared and studied using SEM, TEM, UV-vis diffused reflectance spectra, FT-IR spectroscopy, XPS, and EDS analyses. The photocatalytic activity for methylene blue degradation under visible light was studied and compared with the bare TiO2 and (4,4',4 '',4'-(porphine-5,10,15,20-tetrayl)tetrakis(benzoic acid) with TiO2 (TCPP-TiO2) taken with and without the addition of H2O2. The order of the photocatalytic activity performance was TiO2 < TCPP-TiO2 < SP-TBU-TiO2. The fast and efficient activity of SP-TBU-TiO2 was due to its broad absorption ability. This is the first report of panchromatic TiO2-porphyrin-squarine photocatalysis.