Preparation and photocatalytic properties of ilmenite NiTiO₃ powders for degradation of humic acid in water

Pei-hong Yuan, Cai-mei Fan, Guang-yue Ding, Yun-fang Wang, and Xiao-chao Zhang Institute of Clean Technique for Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China

摘 要：The powders of ilmenite structure NiTiO3 were prepared by a modified Pechini process using tetrabutyl titanate and nickel acetate as raw materials, and using citric acid and ethanol as a chelating agent and a solvent respectively. The powder samples were characterized by thermogravimetric and differential thermal analysis （TG-DTA） and X-ray diffraction （XRD）. The photocatalytic activity of NiTiO3 under the irradiation of ultraviolet rays （UV） light was evaluated by degrading humic acid （HA） in water as a probe reaction. The possible photodegra-dation mechanism was studied by the examination of active species -OH, , and holes （h+） through adding scavengers. The TG-DTA and XRD results indicated that the good crystal structure of ilmenite phase NiTiO3 could be obtained when the Ni-Ti citrate complex was cal-cined at 600°C. The photocatalytic activity experiments indicated that NiTiO3 had favourable photocatalytic activity under the irradiation of UV light, and the photocatalytic degradation rate of HA reached 95.3% after a 2.5 h reaction with the photocatalyst calcined at 600°C and a photocatalyst dosage of 0.4 g/L. The possible photocatalytic mechanism was deduced that holes （h+） and-OH radicals are the major reactive active species in the photocatalytic reaction, and dissolved oxygen plays a weak role in the degradation of HA.

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