Oxygen vacancies assisted ferroelectric heterojunction for enhanced photocatalytic activity

Designing an architecture that ferroelectric materials are introduced oxygen vacancies (OVs) without weakening the ferroelectric polarization has a positive effect on promoting the separation and inhibiting recombination of photogenerated carriers. Here, an indirect strategy that BiOCl rich in OVs were introduced into the positive surface of ferroelectrics to form PTO@BiOCl-OVs heterojunction nanoplates by a simple hydrothermal method and UV light irradiation were reported. The 3% PTO@BiOCl-OVs heterojunction nanoplates displayed an excellent photocatalytic activity for RhB degradation under visible light. ESR signals confirmed that ·O2−, ·OH and 1O2 were the main primary reactive species. TPV response demonstrated that 3% PTO@BiOCl-OVs possessed a negative TPV signal and had the smallest L value of 1.910 × 10−4, which meant the photogenerated carriers had fastest transfer and longest lifetime. Experimental and theoretical analysis collectively demonstrated that the synergistic interaction between ferroelectric polarization, heterojunctions and OVs can promote the separation efficiency, lower the recombination rate of photogenerated carriers and enhance the photocatalytic reactivity.