(1 − x)Bi0.5Na0.5TiO3–xBiFeO3 solid solutions with enhanced piezocatalytic dye degradation

Abstract

Piezocatalysis has received tremendous interest due to the catalytic effect can be triggered by mechanical vibration. Herein, (1 − x)Bi0.5Na0.5TiO3–xBiFeO3 solid solution piezocatalysts were synthesized by a sol–gel method aim to improve the piezocatalytic activities of Bi0.5Na0.5TiO3 (BNT) and BiFeO3 (BFO). The piezocatalytic efficiencies of all obtained solid solution catalysts were improved compared with pure BNT and BFO for methyl orange (MO) degradation as expected. Among them, 0.5BNT–0.5BFO catalyst exhibited outstanding piezocatalytic activity and reusability, the reaction rate constant (0.0615 min−1) was about 5.2 and 3.2 times larger than that of BNT and BFO. Trapping experiments demonstrated that O2− and OH were the main species for MO degradation. Electrochemical measurements indicated that 0.5BNT–0.5BFO exhibited more efficient charge separation efficiency than that of BNT and BFO, which accounts for its efficient catalytic performance. A possible piezocatalytic reaction mechanism was proposed based on band structure and reactive oxygen species (ROS) detection. This work provides a new perspective for designing highly efficient piezocatalysts.