High-efficient Zn0.5Cd0.5S/PbTiO3 S-scheme heterostructure for environmental application: Design and construction of ferroelectric-based artificial-photosynthesized catalyst

The rational design and efficient utilization of room-temperature ferroelectric physical field photocatalysts are of significant importance for addressing energy and environmental challenges. In this work, ferroelectric-based Zn 0.5 Cd 0.5 S/PbTiO 3 S-scheme heterojunction photocatalyst was synthesized via a facile and mild two-step hydrothermal method. The heterostructure was constructed through in-situ selective growth of Zn₀.₅Cd₀.₅S nanoparticles onto the positively polarized surface of PbTiO₃ microplates. The underlying mechanism of this ferroelectric polarization-driven selective growth was systematically investigated through combined theoretical simulations and experimental analyses. Furthermore, the charge transfer behavior within the heterostructure, the synergistic enhancement mechanism of the built-in electric field, and the photocatalytic Cr(VI) reduction performance along with influencing factors were comprehensively examined via DFT calculations and a series of characterization techniques. Zn 0.5 Cd 0.5 S/PbTiO 3 S-scheme heterojunction catalyst integrates three key aspects for boosting photocatalytic efficiency, including the increased solar spectrum response, the enhanced photogenerated charge separation, and the improved surface chemical reaction. As a result, it exhibits an optimal Cr(VI) reduction rate of 15.16 μmol·min⁻¹ ·g⁻¹ , which is 5.5 times higher than that of pristine PbTiO₃. This provides a new design and application of the synergistic and enhanced effect on ferroelectric-based artificial-photosynthesized heterojunction catalyst.