Enhanced piezoelectric catalytic properties of NaNbO3 powder by defects engineering

In this work, NaNbO3 powders were prepared using a hydrothermal method. With increasing the reaction temperature, particle size of NaNbO3 unexpectedly decreases, implying the nucleation-dominated growth mechanism. The piezoelectric catalytic results indicate that the sample reacted at 210 °C for 12 h exhibits the best piezoelectric catalytic efficiency. Furthermore, NaNbO3 powders are annealed in N2 to increase the concentration of oxygen vacancy, which are demonstrated by the impedance and XPS spectra. The simulation results indicate that valence electron of A-site Na cations on the surface is easier than Nb cations to be excited to the conduction band under the influence of oxygen vacancies, which leads to more than 6 times increase in piezoelectric catalytic efficiency.