Nanosheets loaded on tetrahedral surfaces form a Z-type Bi 2 MoO 6 /γ-Bi 2 O 3 heterojunction to enhance the photocatalytic degradation activity of lomefloxacin and Rhodamine B.

The Bi 2 MoO 6 nanosheets are loaded on to γ-Bi 2 O 3 tetrahedron surfaces to form Bi 2 MoO 6 /γ-Bi 2 O 3 heterojunctions using a simple calcination method. The photocatalytic degradation efficiencies of the lomefloxacin and the Rhodamine B using the optimum sample are 96% and 99%, respectively, much higher than that of pure phase samples. When the waters from different regions in China were used as solvents, the removal efficiencies of the lomefloxacin and the Rhodamine B are still higher than 88% and 90%, respectively, which shows excellent prospects for practical applications. The photocatalytic degradation efficiencies of these two pollutants are higher than 91% and 95% in the five cycling tests, and the crystal structure of the sample is not changed after cycling. Based on the first-principles calculation, Bi 2 MoO 6 and γ-Bi 2 O 3 form a Z-type energy band structure which accelerates the separation of the photogenerated charge carriers. The Bi 2 MoO 6 valence band potential of 3.25 V and the γ-Bi 2 O 3 conduction band potential of -0.21 V are reserved to generate ˙OH - and O 2 - , respectively, for the photocatalytic reaction. The degradation of the lomefloxacin is ascribed to the shedding of functional groups and bond breaking with the final products being CO 2 , F - , H 2 O, and NO 3 - . This research shows that Bi 2 MoO 6 /γ-Bi 2 O 3 heterojunctions can be employed to purify domestic and textile industrial sewage.