Hydrogen Generation and Degradation of Organic Dyes by New Piezocatalytic 0.7BiFeO₃-0.3BaTiO₃Nanoparticles with Proper Band Alignment

Piezoelectric materials have recently demonstrated their potential applications in clean energy exploration and environmental remediation through triggering a number of catalytic reactions by harvesting waste vibrational energy in the environment. In this work, unique lead-free 0.7BiFeO3-0.3BaTiO3 (BF-BT) nanoparticles with tuned band structure were synthesized by the hydrothermal method for use as piezoelectric catalysts to generate hydrogen by splitting water; a high production rate of 1.322 mmol/g was achieved in 1 h, which is 10 times higher than the production rate of pure BiFeO3. Of particular interest, BF-BT particles attached to nickel mesh have the ability to degrade rhodamine B in flowing water, demonstrating their potential to treat polluted water by anchoring BF-BT in drains. Finally, we propose novel insight on the piezocatalytic mechanism, which is based on the internal electric field (the sum of the depolarization field and the screening charge field) that drives electron/hole separation and movement.