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Title: Simultaneous Enhancement of Charge Separation and Hole Transportation in a TiO 2 –SrTiO 3 Core–Shell Nanowire Photoelectrochemical System

Efficient charge separation and transportation are key factors that determine the photoelectrochemical (PEC) water‐splitting efficiency. Here, a simultaneous enhancement of charge separation and hole transportation on the basis of ferroelectric polarization in TiO2–SrTiO3core–shell nanowires (NWs) is reported. The SrTiO3shell with controllable thicknesses generates a considerable spontaneous polarization, which effectively tunes the electrical band bending of TiO2. Combined with its intrinsically high charge mobility, the ferroelectric SrTiO3thin shell significantly improves the charge‐separation efficiency (ηseparation) with minimized influence on the hole‐migration property of TiO2photoelectrodes, leading to a drastically increased photocurrent density (Jph). Specifically, the 10 nm‐thick SrTiO3shell yields the highestJphand ηseparationof 1.43 mA cm−2and 87.7% at 1.23 V versus reversible hydrogen electrode, respectively, corresponding to 83% and 79% improvements compared with those of pristine TiO2NWs. The PEC performance can be further manipulated by thermal treatment, and the control of SrTiO3film thicknesses and electric poling directions. This work suggests a material with combined ferroelectric and semiconducting features could be a promising solution for advancing PEC systems by concurrently promoting the charge‐separation and hole‐transportation properties.

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Author(s) / Creator(s):
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Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Advanced Materials
Medium: X
Sponsoring Org:
National Science Foundation
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