Polarization field promoted photoelectrocatalysis for synergistic environmental remediation and H2 production

Polarization field introduced photoelectrocatalytic system has been raised and applied for environmental purification and green fuel generation. Herein, we synthesized the Ag2O/TiO2 nanotubes arrays (TNTs) p-n heterojunction photoanodes and innovatively introduced the SrTiO3 (STO) as a relay to construct a highly stable PEC system. The SrTiO3 layers with the ferroelectric properties were inserted in the interfaces between p-Ag2O and n-TiO2, creating a charge-stable polarized electric field thereby maintaining a constant driving force that promoted the effctive separation of electron and hole between SrTiO3 and TNTs, and prevented the electron transfer from SrTiO3 to Ag2O. Controlling suitable annealing and regulating hydrothermal time could induce SrTiO3 spontaneous polarization, resulting in effective photoinduced charge separation. Consequently, the as-designed TNTs/STO/Ag2O photoanodes exhibited excellent PEC activity and stability (>40 h) for both persistent organic pollutants degradation and synergistic hydrogen evolution owing to the strengthened charge carrier capture ability of solar light and improved photocurrent density.