Selectively constructing sandwich-like heterostructure of CdS/PbTiO 3 /TiO 2 to improve visible-light photocatalytic H 2 evolution

Fast migration and efficient spatial separation of photogenerated charges in photocatalytic materials are indispensable to efficient solar water splitting reactions. Here, we construct a three-phase heterostructure of CdS/PbTiO 3 /TiO 2 by selectively depositing CdS and TiO 2 at oppositely poled crystal facets of PbTiO 3 using single-domain ferroelectric PbTiO 3 . The heterostructure has matching band edge alignments and strong interfacial connections at different moieties. The heterostructure combines the interfacial electrical and ferroelectric fields because of their peculiar microstructures, which provide a strong driving force throughout the whole bulk to separate photogenerated charges. Almost two orders of magnitude improvement of visible-light-driven photocatalytic H 2 production has been realized in CdS/PbTiO 3 /TiO 2 compared with bare PbTiO 3 /TiO 2 , showing the efficiency of charge separation in the heterostructure. The idea of combining ferroelectrics with potential light capture semiconductor provides a paradigm to accurately design charge migration pathways, bringing a step closer to efficient solar water splitting.