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 (
A multifaceted Mo:BiVO4(mf‐BVO) photoanode is grown on F‐doped‐SnO2substrates via achemical bath deposition, and the crystal reconstruction process of mf‐BVO is found to boost the charge transport efficiency significantly for photoelectrochemical (PEC) water splitting. The mf‐BVO exhibits columnar grains with an uncommon (121) texture with high‐index facets such as (112), (020), (132), and (204). The texture and high‐index facets facilitate rapid surface melting and grain fusion during thermal annealing, thus leading to crystal reconstructed micron‐sized BVO grains (cr‐BVO). The cr‐BVO has a photocurrent density ≈50 times larger than that of mf‐BVO. The reason is identified as the significantly improved charge transport efficiency resulting from the dopant activation (increased carrier concentration) and bulky grains (fewer defects). Additionally, the cr‐BVO exhibits improved photocorrosion resistance compared to the nanoparticle‐based BVO. After coating the oxygen evolution catalyst, the photocurrent density of cr‐BVO is further increased to 4.4 mA cm−2for water oxidation reaction at 1.23 V versus the reversible hydrogen electrode, maintaining a high and stable faradaic efficiency of over 88% for 24 h. These results demonstrate that crystal reconstruction is a facile and effective pathway to improve the charge transport efficiency, opening a new avenue for developing efficient photoelectrodes for PEC water splitting.
more » « less- Award ID(s):
- 2029425
- NSF-PAR ID:
- 10388262
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Functional Materials
- Volume:
- 32
- Issue:
- 52
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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J ph). Specifically, the 10 nm‐thick SrTiO3shell yields the highestJ phand 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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Photoelectrochemical (PEC) hydrogen generation is a promising solar energy harvesting technique to address the concerns about the ongoing energy crisis. Antimony selenide (Sb2Se3) with van der Waals‐bonded quasi‐1D (Q1D) nanoribbons, for instance, (Sb4Se6)
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