Exploring the piezocatalytic dye degradation capability of lithium niobate

The piezocatalysis dye degradation capability of LiNbO3 is reported for the first time. LiNbO3 was synthesized using a conventional solid-state reaction route. X-ray diffraction and Raman spectroscopy confirmed the formation of a single-phase of LiNbO3 in the as-synthesized material. Scanning electron microscope showed the micron-sized (0.2–2 μm) particles of LiNbO3 powder. The average pore diameter, the specific surface area, and total pore volume of LiNbO3 powder were measured to be 3.3 nm, 4.856 m2/g and 0.008 cc/g respectively. During piezocatalysis experiments using ultrasonicator, 0.1 g of LiNbO3 sample degraded ~99%, 93%, and 80% of methylene blue dye from the dye solution of 12 mg/L initial concentration during the first, second and third piezocatalysis cycle, respectively. The radical trapping experiments found the main active species behind the piezocatalysis dye degradation through LiNbO3 sample in this order: hydroxyl radical ([rad]OH) > superoxide radical ([rad]O2-) > holes (h+). LiNbO3 sample could be a promising candidate for the piezocatalytic degradation of organic dyes from the waste-water. © 2020 The Society of Powder Technology Japan