Solar-mechanical H<sub>2</sub>O<sub>2</sub> production powered by defect dipole polarization in a nonpolar semiconductor.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 42139328.
- Also identified by DOI 10.1126/sciadv.aec8743 and PMC identifier 13178571.
- Licence recorded as CC BY-NC.
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Abstract
Piezo-photocatalytic H<sub>2</sub>O<sub>2</sub> production faces a central challenge: inadequate visible-light absorption and insufficient driving forces for charge separation, especially in wide-bandgap nonpolar semiconductors. To address this, we propose a strategy that constructs Cu<sup>+</sup>-oxygen vacancy defect dipoles within nonpolar ZrO<sub>2</sub> to enable piezo-photo coupling. Under ultrasonic excitation, these defect dipoles produce a robust piezoelectric polarization field that facilitates directional separation of photogenerated carriers. As a result, charge recombination at visible-light-absorbing defect states is effectively suppressed, enabling synergistic utilization of mechanical and optical energy. The optimized catalyst exhibits a remarkable H<sub>2</sub>O<sub>2</sub> production rate of 415.36 μmol·g<sup>-1</sup>·hour<sup>-1</sup> under ambient air/water conditions and achieves near-complete degradation (88.7%) of rhodamine B in continuous-flow wastewater treatment (1 liter within 60 min). Theoretical calculations further reveal that the defect dipoles lower the d-band center of the active sites, thereby promoting *OH desorption and accelerating H<sub>2</sub>O<sub>2</sub> formation kinetics. This study offers a viable strategy for inducing piezoelectricity in nonpolar semiconductors, thereby establishing design principles for high-performance piezo-photocatalytic systems.