Insight into the piezo-photo coupling effect of PbTiO3/CdS composites for piezo-photocatalytic hydrogen production

The polarization field with the function in carrier separation has aroused substantial interest. For heterojunction complexes, however, the static polarization field will be inevitably shielded by a large number of carriers. Herein, a novel hybrid consisted of single-domain PbTiO3 coated by CdS particles was selected as a model material to prove that the alternating piezoelectric field induced by periodic stress can destroy shielding effect. After the introduction of alternating piezoelectric potential by using ultrasonication, PbTiO3/CdS-10 % exhibited a much higher H2 production rate by piezo-photocatalysis (849.0 μmol h−1 g−1) than by individual piezocatalysis (400.6 μmol h−1 g−1) or photocatalysis (98.9 μmol h−1 g−1). Furthermore, the finite element simulation shows that PbTiO3/CdS heterostructure has a superior piezoelectric potential difference compare to pure PbTiO3 or pure CdS. Based on data analysis, the mechanism about the piezo-photo coupling effect was proposed, which will provide a reference for the design and development of high-efficiency piezo-photocatalyst.