Synthesis and visible-light photocatalytic activity of brookite/BiOBr.

Brookite TiO₂ was synthesized and BiOBr was supported on the surface of brookite TiO₂ by a hydrothermal method. X-ray diffraction and X-ray photoelectron spectroscopy analyses of the composites confirmed the formation of brookite TiO₂/BiOBr. Transmission electron microscopy results confirmed the as-prepared composites were nano-sized. The optimum loading amount of BiOBr was 30%. The photocatalytic results show that the degradation efficiency of rhodamine B by titanite TiO₂/BiOBr (30%) under visible-light irradiation for 2 h is close to 100%. ^•O₂^– and h⁺ are the main active species during the photocatalytic process. The improvement of photocatalytic activity might be because the formation of p–n hetero-junction enhanced the separation efficiency of photogenerated electron–hole pairs. The photocurrent density of the brookite/BiOBr (30%) was about 2 times higher than that of pure brookite. [ABSTRACT FROM AUTHOR]