酞菁钴磺酸盐在纳米TiO_2薄膜上的固载化及对亚甲基蓝的降解作用(英文)

Immobilization of Various Cobalt(Ⅱ) Phthalocyanine Sulphonates on Nanocrystalline TiO_2 Thin Films and Their Effect on Degradation of Methylene Blue

合成了单、双、三核酞菁钴磺酸盐[single-nuclear cobalt(Ⅱ)phthalocyanine tetrasulphonates,s-CoPc;bi-nuclear cobalt(Ⅱ)phthalocyanine hexasulphonates,b-CoPc;tri-nuclear cobalt(Ⅱ)phthalocyanine octasulphonates,t-CoPc],并将其固载于纳米TiO2薄膜上,测量了s-CoPc,b-CoPc和t-CoPc水溶液的紫外可见光谱,利用红外光谱表征t-CoPc在纳米TiO2粉末上的吸附特性。以空气为氧化剂,比较了3种CoPc/纳米TiO2薄膜在可见光照射和黑暗条件下对亚甲基蓝(methylene blue,MB)降解的光催化和催化活性。结果表明:b-CoPc和t-CoPc的Q带最大吸收峰分别从s-CoPc的655 nm红移至658 nm和663 nm,且t-CoPc可通过其中部分磺酸基固载于纳米TiO2薄膜上。MB降解实验结果表明:3种CoPc均可以敏化纳米TiO2薄膜,明显提高其光催化活性与黑暗条件下的催化活性(其次序为t-CoPc>b-CoPc>s-CoPc)。将CoPc固载于纳米TiO2薄膜上可使纳米TiO2的光谱响应拓展到可见光区,且在降解MB过程中容易回收再利用。

Single-nuclear cobalt（Ⅱ） phthalocyanine tetrasulphonates（s-CoPc）,bi-nuclear cobalt（Ⅱ） phthalocyanine hexasulphonates（b-CoPc） and tri-nuclear cobalt（Ⅱ） phthalocyanine octasulphonates（t-CoPc） were synthesized and immobilized on nanocrystalline TiO2 thin films.The ultraviolet–visible（UV–Vis） spectra of s-CoPc,b-CoPc and t-CoPc in aqueous solution were examined,and the adsorption of t-CoPc on the nanocrystalline TiO2 powder was investigated by infrared（IR） spectrometer.The photocatalytic and cata-lytic activity of various CoPc/nanocrystalline TiO2 thin films was evaluated by degradation of methylene blue（MB） aqueous solution with air as an oxidant under visible light irradiation and dark condition.From the UV–Vis spectra,the Q-band of b-CoPc and t-CoPc shifts from 655 nm of s-CoPc to 658 and 663 nm,respectively.The IR spectra indicate that the TiO2 could bind t-CoPc by interactions between some sulfonic groups of t-CoPc and nanocrystalline TiO2 powder.According to the degradation result,various CoPc could sensitize nanocrystalline TiO2 thin films and improve their photocatalytic activity and catalytic activity under dark condition（t-CoPcb-CoPcs-CoPc）,and the order is similar to that of catalytic activity under dark condition.The CoPc/nanocrystalline TiO2 thin films for the utilization of solar energy in a large scale could be recycled in degradation of MB.