Ferroelectric polarization-electric field promoted S-scheme CdSe/BaxSr1-xTiO3 for highly efficient solar hydrogen evolution

Abstract

Coupling the ferroelectric polarization and internal electric field to realize effective separation and migration of photogenerated charges is highly attractive for accomplishing efficient photocatalytic hydrogen production. In this work, an internal electric field modulated S-scheme heterostructure was fabricated by depositing CdSe on ferroelectric BaxSr1-xTiO3 (BxST) through an in-situ growth method. Because of the oriented powerful electron transport driven by the strong spontaneous polarization and internal electric field, the as-synthesized CdSe/BxST heterojunctions demonstrated excellent solar to H2 performance. Without the addition of noble metal cocatalyst, 7% CdSe/B0.8ST exhibited a H2 evolution rate of 1971.8 µmol g-1 h−1 with an apparent quantum yield of 12.1% at 365 nm. Moreover, the obtained heterojunction catalysts exhibit good stability after 12 h continuous irradiation. This work provides a viable strategy on the utilization of ferroelectric polarization and internal electric field strategy to promote charge transfer and separation of S-scheme photocatalysts.