Unveiling charge utilization mechanisms in ferroelectric for water splitting

Charge separation is a critical process for achieving high photocatalytic efficiency, and ferroelectrics hold significant potential for facilitating effective charge separation. However, few studies have demonstrated substantial photocatalytic activity in these materials. In this study, we demonstrate that in ferroelectric PbTiO₃, surface Ti vacancy defects near the positively polarized facets impede photocatalytic performance by trapping electrons and inducing their recombination. To tackle this issue, we selectively grew SrTiO₃ nanolayers on the polarized facets PbTiO₃, effectively mitigating interface Ti defects. This modification establishes a efficient electron transfer pathway at the interface between the positively polarized facets and the cocatalyst, extending the electron lifetime from 50 microseconds to the millisecond scale and significantly increasing electron participation in water-splitting reactions. Consequently, the apparent quantum yield for overall water splitting achieves the highest values reported to date for ferroelectric photocatalytic materials. This work provides an effective strategy for designing advanced ferroelectric photocatalytic systems.