Spatially selective visible light photocatalytic activity of TiO2/BiFeO3 heterostructures

Zhang, Shujun; Schultz, Andrew M.; Salvador, Paul A.; Rohrer, Gregory S.

doi:10.1039/c0jm04313c

Cited by 126 publications

(91 citation statements)

References 72 publications

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“…Morphological control has been suggested as another way to limit recombination. [24] It is also possible to separatec harges by using internal polarizationsand charged surfaces, [25,26] though the importance of these phenomenahas not yet been fully explored. [27] In this work, we have demonstrated that nanoporous hydrogen-reduced BiVO 4 (H-BiVO 4Àx )c oupled with Ni-B i electrocatalysts exhibits superior properties as photoanodes, including an improved photocurrentr esponse and solar energy conversion efficiency.S pecifically, by adoptingafast, simple, and robust electrochemical deposition method, [28] we createdn anoporous structures of BiVO 4.…”

Section: Introductionmentioning

confidence: 99%

Efficient Photoelectrochemical Water Oxidation over Hydrogen‐Reduced Nanoporous BiVO₄ with Ni–B_i Electrocatalyst

Gan

Rajeeva

et al. 2015

ChemElectroChem

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BiVO4 is one of the most promising candidates for photoanodes in solar water splitting. However, the poor charge‐separation yield in BiVO4 has limited its photochemical activity. Here, we overcome this limitation by constructing a nanoporous morphology that effectively inhibits bulk carrier recombination as well as undergoes controlled introduction of oxygen vacancies through hydrogenation. In comparison to pristine BiVO4, hydrogen‐treated BiVO4 (H‐BiVO4−x) exhibits a superior photocurrent and electron‐hole separation yield, owing to enhanced carrier density and conductivity. In addition, we adopt a layer of nickel–borate (Ni–Bi) complex on the H‐BiVO4−x surface as an oxygen evolution catalyst to improve the water oxidation kinetics. The Ni–Bi/H‐BiVO4−x photoanode results in a large cathodic shift (350 mV) in the onset potential for water oxidation at pH 9. Moreover, the photoanodes exhibit high performance in the low‐bias regime and achieve a maximum power point of 0.82 % (photon‐to‐current efficiency) for solar water oxidation at potentials as low as 0.79 V versus RHE with a photocurrent of 2.26 mA cm−2. We attribute these improved photoelectrochemical performances to the enhanced charge separation, higher carrier density, better conductivity of H‐BiVO4−x, and the role of Ni–Bi as a hole conductor, facilitating photogenerated electron mobilization.

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Section: Introductionmentioning

confidence: 99%

Efficient Photoelectrochemical Water Oxidation over Hydrogen‐Reduced Nanoporous BiVO₄ with Ni–B_i Electrocatalyst

Gan

Rajeeva

et al. 2015

ChemElectroChem

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“…Zhang et al [7] have fabricated BFO with TiO 2 by a pulsed laser deposition method. They 6 investigated that titania can be made photochemically active under visible light with a wavelength of 460 nm by supporting on BFO substrate.…”

Section: Introductionmentioning

confidence: 99%

“…The ferroelectric properties of BFO with spontaneous polarization lead to the band bending that transports the photoinduced charge carriers (electrons and holes) in opposite directions, which enhances the reactivity and separation efficiency of the photo-generated charges [6]. However, the photocatalytic efficiency of BFO is still limited due to its low conduction band position compared to the hydrogen (or O 2 ) reduction level [7], and usually small surface areas for catalytic reactions.…”

Section: Introductionmentioning

confidence: 99%

Enhanced visible-light activities of porous BiFeO3 by coupling with nanocrystalline TiO2 and mechanism

Humayun

Zada

et al. 2016

Applied Catalysis B: Environmental

230

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“…Experimental studies have shown that the surface reactivity of TiO 2 is directly influenced and improved by the underlying ferroelectric domain structure, an effect that has been attributed to the combined efficient absorption and charge separation in the ferroelectric substrate and transport across the TiO 2 =substrate interface [12,13]. Despite some encouraging results [13,14], however, the interest in such TiO 2 =ferroeletric heterostructures has remained limited. In particular, their physical properties are largely unexplored and an atomic-scale understanding of their reactivity is missing.…”

mentioning

confidence: 99%

TiO2 /Ferroelectric Heterostructures as Dynamic Polarization-Promoted Catalysts for Photochemical and Electrochemical Oxidation of Water

Lee

Selloni

2014

Phys. Rev. Lett.

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Using first-principles density functional theory calculations, we explore the chemical activity of epitaxial heterostructures of TiO 2 anatase on strained polar SrTiO 3 films focusing on the oxygen evolution reaction (OER), the bottleneck of water splitting. Our results show that the reactivity of the TiO 2 surface is tuned by electric dipoles dynamically induced by the adsorbed species during the intermediate steps of the reaction while the initial and final steps remain unaffected. Compared to the OER on unsupported TiO 2 , the combined effects of the dynamically induced dipoles and epitaxial strain strongly reduce rate-limiting thermodynamic barriers and significantly improve the efficiency of the reaction. DOI: 10.1103/PhysRevLett.112.196102 PACS numbers: 82.45.Jn, 82.45.Un, 82.50.−m, 77.55.fp Titanium dioxide (TiO 2 ) is widely used in photocatalysis and solar energy conversion due to its many favorable properties, like stability against photocorrosion and proper band alignment relative to the water redox potentials [1][2][3]. However, the efficiency of TiO 2 is notoriously low, and efforts at improving it through modifications such as doping [4] or synthesis of (nano)crystals exposing highly reactive facets [5] have encountered only limited success. Among the possible alternatives to TiO 2 , polar materials have recently attracted significant interest because their surface dipoles can react easily with charged species and supply built-in electric potentials to increase the carrier mobility [6,7]. However, control of the surface reactivity of these materials is difficult [8], e.g., because exposed surface dipoles often cause undesired atomic or electronic reconstructions and unexpected adsorption of charged species which can interfere with the reaction of interest [9][10][11]. Less well known than TiO 2 and polar semiconductors are heterostructures composed of stable TiO 2 thin films supported by a ferroelectric substrate [12,13]. Experimental studies have shown that the surface reactivity of TiO 2 is directly influenced and improved by the underlying ferroelectric domain structure, an effect that has been attributed to the combined efficient absorption and charge separation in the ferroelectric substrate and transport across the TiO 2 =substrate interface [12,13]. Despite some encouraging results [13,14], however, the interest in such TiO 2 =ferroeletric heterostructures has remained limited. In particular, their physical properties are largely unexplored and an atomic-scale understanding of their reactivity is missing.We present here a first-principles density functional theory (DFT) study of TiO 2 =ferroelectric heterostructures, which provides evidence that these composite materials can have a substantially enhanced reactivity relative to TiO 2 . We focus on model heterostructures composed of a TiO 2 (001) film of anatase (the TiO 2 polymorph most efficient for photocatalysis [15]) supported by a nearly ferroelectric SrTiO 3 (STO) substrate that can easily acquire a macroscopic polarization in the p...

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Spatially selective visible light photocatalytic activity of TiO2/BiFeO3 heterostructures

Cited by 126 publications

References 72 publications

Efficient Photoelectrochemical Water Oxidation over Hydrogen‐Reduced Nanoporous BiVO₄ with Ni–B_i Electrocatalyst

Efficient Photoelectrochemical Water Oxidation over Hydrogen‐Reduced Nanoporous BiVO₄ with Ni–B_i Electrocatalyst

Enhanced visible-light activities of porous BiFeO3 by coupling with nanocrystalline TiO2 and mechanism

TiO2 /Ferroelectric Heterostructures as Dynamic Polarization-Promoted Catalysts for Photochemical and Electrochemical Oxidation of Water

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Spatially selective visible light photocatalytic activity of TiO2/BiFeO3 heterostructures

Cited by 126 publications

References 72 publications

Efficient Photoelectrochemical Water Oxidation over Hydrogen‐Reduced Nanoporous BiVO4 with Ni–Bi Electrocatalyst

Efficient Photoelectrochemical Water Oxidation over Hydrogen‐Reduced Nanoporous BiVO4 with Ni–Bi Electrocatalyst

Enhanced visible-light activities of porous BiFeO3 by coupling with nanocrystalline TiO2 and mechanism

TiO2 /Ferroelectric Heterostructures as Dynamic Polarization-Promoted Catalysts for Photochemical and Electrochemical Oxidation of Water

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Efficient Photoelectrochemical Water Oxidation over Hydrogen‐Reduced Nanoporous BiVO₄ with Ni–B_i Electrocatalyst

Efficient Photoelectrochemical Water Oxidation over Hydrogen‐Reduced Nanoporous BiVO₄ with Ni–B_i Electrocatalyst