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 (C 12 H 10 O 2 ) as the raw materials, an innovative axial substituted SubPc H 12 SubPcB‐OPh 2 OH 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 H 12 SubPcB‐OPh 2 OH. To expand photocatalytic activities for organic dyes degradation, H 12 SubPcB‐OPh 2 OH was decorated onto surface of TiO 2 nanoparticles to fabricate high‐efficiency H 12 SubPcB‐OPh 2 OH/TiO 2 photosensitive catalysts. The degradation experiments indicated that the H 12 SubPcB‐OPh 2 OH/TiO 2 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 TiO 2 in 180‐min, respectively. Under the same conditions, the photocatalytic rate of H 12 SubPcB‐OPh 2 OH/TiO 2 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 TiO 2 for MO, BB, MB, and AF degradation under visible‐light irradiation, respectively. Besides, after five cycles of experiments, the degradation rate of H 12 SubPcB‐OPh 2 OH/TiO 2 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 TiO 2 . This study provides a new idea to the construction of photosensitive catalysts based on TiO 2 for water purification.