Remarkable enhancement of photocatalytic performance via constructing a novel Z-scheme KNbO 3 /Bi 2 O 3 hybrid material

Abstract KNbO 3 /Bi 2 O 3 composite materials with different percentage of KNbO 3 have been prepared by simple methods The structural and optical properties of the resulting samples are thoroughly characterized by XRD, UV–vis DRS, SEM, TEM, and N 2 -sorption analysis. The photocatalytic activities of the as-prepared materials for the degradation of rhodamine B (RhB) and methyl orange (MO) are evaluated under UV-light irradiation. The results indicate that the optimal loading amount of KNbO 3 is 30 wt.% (i. e., 30 wt.% KNbO 3 /Bi 2 O 3 ), The rate constants of which for the RhB and MO degradation are about 3.7 times and 4.1 times faster than those of pure Bi 2 O 3 and approximately 6.9 times and 7.1 times faster than those of pure KNbO 3 , respectively. Based on a series of characterizations, it can be concluded that the migration of photogenerated carriers adopts a direct Z-scheme mechanism and O 2− , OH, and h + are the main reactive species in the photocatalytic reactions.