Novel axial substituted subphthalocyanine sensitized titanium dioxide H12SubPcB‐OPh2OH/TiO2 photocatalyst: Synthesis, density functional theory calculation, and photocatalytic properties

Abstract

Utilizing subphthalocyanine (SubPc) and 4,4′‐dihydroxybiphenyl (C12H10O2) as the raw materials, an innovative axial substituted SubPc H12SubPcB‐OPh2OH was synthesized by solvothermal method. The density functional theory (DFT) and time‐dependent density functional theory (TD‐DFT) calculations were employed to further study the properties and structures of H12SubPcB‐OPh2OH. To expand photocatalytic activities for organic dyes degradation, H12SubPcB‐OPh2OH was decorated onto surface of TiO2 nanoparticles to fabricate high‐efficiency H12SubPcB‐OPh2OH/TiO2 photosensitive catalysts. The degradation experiments indicated that the H12SubPcB‐OPh2OH/TiO2 catalyst with the mass ratio of 1:25 had the greatest performance in the elimination of methyl orange (MO), bromophenol blue (BB), methylene blue (MB), and acid fuchsin (AF). The 29.4%, 72.5%, 27.6%, and 64.8% of MO, BB, MB, and AF was removed by pure TiO2 in 180‐min, respectively. Under the same conditions, the photocatalytic rate of H12SubPcB‐OPh2OH/TiO2 can reach 96.3%, 99.5%, 97.5%, and 99.5%, separately. The efficiency of the as‐synthesized composite was 3.3, 1.4, 3.5, and 1.5 times higher than that over bare TiO2 for MO, BB, MB, and AF degradation under visible‐light irradiation, respectively. Besides, after five cycles of experiments, the degradation rate of H12SubPcB‐OPh2OH/TiO2 photocatalyst to BB can still reach 90.2%, which demonstrated that the obtained photocatalysts possessed remarkable stability and is much higher than 15.6% of pure TiO2. This study provides a new idea to the construction of photosensitive catalysts based on TiO2 for water purification.