A novel synthesis for the preparation of LiNbO3 powder with high piezoelectric catalytic performance

The traditional method for producing lithium niobate (LiNbO3) powder is based primarily on a solid-state reaction, which has a high energy consumption and low efficiency, requiring long periods of insulation at a high temperature of 1000–1300 °C. In this work, high-purity and high-crystallinity LiNbO3 powder was prepared by using niobium pentoxide (Nb2O5) and lithium fluoride (LiF) at 800 °C for 0.5 h. Interestingly, the prepared LiNbO3 powder demonstrated exceptional piezoelectric catalytic degradation performance and reusability. Under the influence of ultrasonic waves, the LiNbO3 powder achieved complete degradation of Rhodamine B (RhB) within a remarkably short duration of 20 min, with a reaction rate constant of 0.2702 min−1, which was 7.9 times larger than that of commercial LiNbO3 (0.03416 min−1). Furthermore, even after undergoing six degradation cycles, the powder maintained its high degradation efficiency. Active substance trapping and detection experiments revealed the presence of hydroxyl radicals (•OH) and superoxide radicals (•O2−) with potent oxidizing capabilities during the piezoelectric catalysis process, affirming their pivotal roles in the degradation of RhB. The energy-saving and efficient method employed in acquiring LiNbO3 would provide an exciting pathway towards the development of efficient catalysts for organic wastewater treatment, fueled by clean energy sources.