The internal electric field induced
by a piezoelectric effect is
a promising method to suppress rapid electron–hole recombination
of photocatalysis for environmental remediation. Herein, we fully
utilized both piezoelectric and photocatalytic properties of Bi2WO6 nanoplates for the removal of organic pollutants.
The degradation rate constant of piezo-photocatalysis is dramatically
boosted to 0.077 min–1 by the Bi2WO6 nanoplates, which is 4.2-fold of the photocatalysis alone.
The superior catalytic activity of Bi2WO6 nanoplates
was attributed to the accelerated electron–hole pair separation
efficiency associated with the enhancement of the piezoelectric effect-induced
internal electric field. Based on the theoretical calculation, the
bandgap of Bi2WO6 nanoplates would decrease
from 1.99 to 1.67 eV under mechanical strains, indicating that broader
light harvesting and faster charge transfer can be achieved with the
assistance of the piezoelectric field. Accordingly, multiple reactive
oxygen species (·O2
– and ·OH)
are dominant for the degradation activity based on the quenching experiments
and EPR analysis, outperforming piezocatalysis and photocatalysis.
We have provided a new strategy to improve the catalytic decontamination
performance.