Enhanced catalytic activity of Molar-like BaTiO3 by oxygen vacancies.

Oxygen vacancies are found to have significant effects on the piezo-photocatalytic performance. For this reason, Molar-like and Bamboo-like BaTiO 3 with the same tetragonal phase are synthesized by a two-step hydrothermal method. Molar-like BaTiO 3 exhibits a superior piezo-photocatalytic performance by degrading the organic dye indigo carmine (IC), whose kinetic constant of 0.099 min−1 is 1.80 times higher than that of Bamboo-like BaTiO 3. The same conclusion is drawn while the differences in specific surface areas are eliminated. There are more oxygen vacancies in Molar-like BaTiO 3 compared to Bamboo-like BaTiO 3 , as shown in XPS results. The oxygen vacancies are favorable for light adsorption and O 2 activation, thus an excellent photocatalytic performance is achieved. XRD refinements show that Molar-like BaTiO 3 has a slightly higher content of piezoelectric tetragonal phase and stronger lattice distortion than Bamboo-like BaTiO 3. However, the piezoelectric polarization of Molar-like BaTiO 3 is weakened and the number of effective carriers is reduced due to more oxygen vacancies. The presented work provides a profound reference for the structural design of catalysts. [ABSTRACT FROM AUTHOR]