Insights into the tribo-/pyro-catalysis using Sr-doped BaTiO₃ ferroelectric nanocrystals for efficient water remediation

Ferroelectric materials have multiple characteristics in ferroelectric, piezoelectric, pyroelectric properties, which provide an attractive prospect for simultaneously harvesting multiple energy sources for catalytic applications. However, the crucial challenge for wastewater purification lies in the development of ferroelectric materials with improved functions and the design of advanced oxidation processes. Herein, Sr_0.3Ba_0.7TiO₃ (SBT-0.3) nano-catalysts modified by PVP surfactant could significantly promote water recovery efficiency from the rhodamine B (RhB), which is as high as 98% by simultaneously collecting two types of energy sources of mechanical friction and temperature fluctuation from the natural environment for tribo-/pyro-catalysis under dark conditions. It was found that the samples containing PVP surfactant show significantly improved performance in the separation of charge carriers in comparison with those without PVP surfactant. The permanent polarization in SBT-0.3, coupled with the piezo-/pyro-potential, could generate internal field and therefore reduce charge recombination. It also helps to absorb charged species from the dye solution, which favors the reaction with active oxygen to cause the cleavage and breakdown of organic molecules. The mechanism of RhB decomposition mediated by SBT-0.3 ferroelectric is also discussed. This work favors us to in-depth understanding for the tribo-/pyro-catalysis and hence proposes a new strategy to improve the water purification efficiency of ferroelectric nanocrystals.