Open AccessStudy on the photocatalytic mechanism of tio2 sensitized by zinc porphyrin
Author(s) -
Pei-Xin Li,
Mingyang Feng,
WU Cai-ping,
Shaobo Li,
Hou Lei-Tian,
Ma Jia-Sai,
Chang Yin
Publication year - 2015
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.64.137601
Subject(s) - photocatalysis , electron paramagnetic resonance , photochemistry , porphyrin , materials science , zinc , visible spectrum , spectroscopy , methyl orange , electron transfer , absorption spectroscopy , catalysis , chemistry , nuclear magnetic resonance , optoelectronics , optics , organic chemistry , physics , quantum mechanics , metallurgy
We have investigated the photocatalysis efficiency and electron transfer of the znic prophyrin/TiO2 composite photocatalyst, a sensitised hybrid porphyrin material, and prepared it successfully by sol-gel method. The UV-visible spectroscopy and electron paramagnetic resonance spectra are used to analyze and characterize the znic prophyrin/TiO2 composite photocatalyst. The proportions 0%, 0.2%, 0.5% and 0.9% (mass ratio) of zinc porphyrin, and the photocatalytic mechanism of TiO2 sensitized by zinc porphyrin are reasonably explained by ultraviolet visible spectroscopy and electron paramagnetic resonance spectroscopy (EPR). Different samples' UV-visible spectra show that the degradation efficiency of methyl orange solution by TiO2 may be improved via adding appropriate amount of zinc porphyrin sensitizer. Prohibitive incorporation of the sensitizer would cause excess of particles in the mixed catalyst, leading to the TiO2 surface covered by the sensitizer, thus affecting the absorption of photons, and the light degradation rate of TiO2 may be lowered, even lower than the pure TiO2. EPR spectra show the excited state of electrons in zinc prophyrin generated by irradiation of light can promote the generation of Ti3+ with strong oxidizing and superoxide radicals when using UV-visible light to irradiate the powder samples, thus effectively enhancing the separation of photogenerated electron-hole pairs, and improving the photocatalytic performance of TiO2.