Three-Phase Mixed Titania Powder Modified by Silver and Silver Chloride with Enhanced Photocatalytic Activity under UV-Visible Light

Pure and Ag/AgCl-modified titania powders with anatase/rutile/brookite three-phase mixed structure were prepared by one-step hydrothermal method. The effects of Ag/Ti atomic percentages on the structure and photocatalytic performance of TiO2 were investigated. The results showed that pure TiO2 consisted of three phases, anatase, rutile, and brookite, and that Ag addition promoted the transformation from anatase to rutile. When the molar ratio of Ag/Ti reached 4%, the AgCl phase appeared. The addition of Ag had little effect on the optical absorption of TiO2; however, it did favor the separation of photogenerated electrons and holes. The results of photocatalytic experiments showed that after Ag addition, the degradation degree of rhodamine B (RhB) was enhanced. When the molar ratio of Ag/Ti was 4%, Ag/AgCl-modified TiO2 exhibited the highest activity, and the first-order reaction rate constant was 1.67 times higher than that of pure TiO2.

Automated summary

The study prepared pure TiO2 and Ag/AgCl-modified TiO2 with different structures and performances by hydrothermal method. It was found that the addition of Ag can promote the phase transformation of TiO2 and the separation of photogenerated electrons and holes, thereby improving the photocatalytic degradation of Rhodamine B.