Selectively constructing sandwich-like heterostructure of CdS/PbTiO3/TiO2 to improve visible-light photocatalytic H2 evolution

Abstract

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.

Spatially Separated Redox Cocatalysts on Ferroelectric Nanoplates for Improved Piezophotocatalytic CO2 Reduction and H2O Oxidation

“…As illustrated in Figure a, monocrystalline PbTiO 3 nanoplates are first prepared through a hydrothermal method, which are dominated by {001} facets with edge lengths of 500–1000 nm and thicknesses of 200–300 nm (Figures b and S1a,b). − The inherent ferroelectric spontaneous polarization characteristic of as-synthesized PbTiO 3 nanoplates is demonstrated by typical ferroelectric hysteresis loops (Figure S1c). Then, photodeposition of AuCu on the surface of PbTiO 3 is carried out using HAuCl 4 and Cu­(NO 3 ) 2 as precursors as well as Na 2 S and Na 2 SO 3 as hole scavengers.…”

PbTiO3 Based Single-Domain Ferroelectric Photocatalysts for Water Splitting

“…The combination of the interfacial electrical and ferroelectric fields is able to drive a high-efficiency separation of photoexcited charges throughout the whole heterostructure. Consequently, CdS/PbTiO 3 /TiO 2 delivers 2 orders of magnitude and over 2 times improvement in photocatalytic H 2 production under visible-light irradiation, compared to PTiO 3 /TiO 2 and CdS/PbTiO 3 , respectively …”

“…(f) Comparison of average photocatalytic H 2 production rates of PbTiO 3 /TiO 2 , CdS/PbTiO 3 , and CdS/PbTiO 3 /TiO 2 after calcination at 500 °C. Reproduced with permission from ref . Copyright 2022 Springer Nature Publishing AG.…”

“…Consequently, CdS/PbTiO 3 /TiO 2 delivers 2 orders of magnitude and over 2 times improvement in photocatalytic H 2 production under visible-light irradiation, compared to PTiO 3 /TiO 2 and CdS/PbTiO 3 , respectively. 42…”

Advanced materials and energy technologies towards carbon neutrality

“…In this technology, fast migration and spatial separation of photogenerated charges are key to improve the device efficiency. Wan et al [16] have made a CdS/PbTiO 2 /TiO 2 heterostructure catalyst with combined interfacial electrical and ferroelectric fields which can efficiently separate charges and lead to two orders of magnitude improvement of photocatalytic hydrogen production. In addition, Yang et al [17] have doped Al into the lattice of LaTaON 2 , which maintains the light absorption property, inhibits the defect concentration, and increases the surface hydrophilicity of the catalysts, leading to much enhanced photocatalytic water oxidation performance.…”