改性A-TiO2制备及其可见光催化降解酚红

用水热法制备了TiO₂粉末,试样经X射线衍射(XRD)和傅立叶交换红外光谱(FT-IR)表征,研究了TiO₂粉末对酚红的降解过程,探索影响光催化效率的最佳条件。结果表明,TiO₂晶相为单一的锐钛矿型,即制备了A-TiO₂,在1 600和3 400 cm^-1处的吸收表明粉末中有大量羟基(OH)存在。掺适量铁导致A-TiO₂的吸收波长产生了"红移现象",即扩大了催化剂对光谱的吸收范围。当A-TiO₂中的掺摩尔分数为3%铁时,经40 W白炽灯照射60 min,比不掺铁的A-TiO₂催化效率提高了37.4%。光催化的最佳条件为:酚红溶液初始质量浓度45 mg/L、溶液pH为7、掺摩尔分数为3%铁的A-TiO₂的质量浓度为2.0 g/L、室温18℃下40 W白炽灯照射60 min,酚红的最大降解率为44.49%。

Preparation of Modified A-TiO2 and Its Photocatalytic Degradation of Phenol Red under Vis-Light

TiO₂ powder was prepared via hydrothermal method, and was characterized by X-ray diffraction(XRD) and Fourier transform infrared spectrometer(FT-IR). The degradation process of phenol red by TiO₂ powder was studied, and the optimum conditions affecting the photocatalytic efficiency were explored. The results showed that the crystal phase of TiO₂ is of a single anatase type, that is, A-TiO₂ was prepared;the samples contain a large number of hydroxys corresponding to the absorption of 1 600 and 3 400 cm^-1. The absorption wavelength of A-TiO₂ is red-shifted due to proper amount of doped iron, which expands the range of absorption spectrum. When the mole fraction of doped iron in A-TiO₂ is 3%, the photocatalytic efficiency is 37.4% higher than that without iron in A-TiO₂ by irradiation(40 W incandescent lamp) for 60 min. The optimum photocatalytic conditions are as follows: initial mass concentration of phenol red solution is 45 mg/L, pH is 7.0, mass concentration of A-TiO₂ with 3% of doped iron is 2.0 g/L, and the illumination time is 60 min under vis-light(40 W incandescent lamp) at room temperature(18 ℃), thus the maximum degradation rate of phenol red is 44.49%.