Ferroelectric polarization in Bi_0.9Dy_0.1FeO₃/g-C₃N₄ Z-scheme heterojunction boosts photocatalytic hydrogen evolution

Delivering excellent carrier separation through ferroelectric polarization is desirable to achieve effective solar hydrogen conversion. Here, Bi_0.9Dy_0.1FeO₃/g-C₃N₄ (BDFO/GCN) Z-scheme photocatalyst was constructed by loading BDFO nanoparticles onto sheet-like GCN, in which BiFeO₃ (BFO) was doped with the rare-earth element Dy to narrow the optical bandgap and enhance the ferroelectric property. Residual polarization effectively promoted the separation and transport of photo-generated carriers in BFO, and the Z-scheme exhibited stable reaction activity during photocatalytic degradation and photocatalytic hydrogen evolution. Through electric polarization, the heterojunction photocatalyst achieves 100% degradation of Rhodamine B (RhB) under simulated sunlight. The evolution rate of hydrogen was improved from approximately 742.5 to 1084.0 µmol·g⁻¹·h⁻¹ after polarization. This remarkable activity is attributed to the improved carrier separation facilitated by the internal polarization field. This work offers novel insights into the rational design of efficient ferroelectric photocatalysts.