Intrinsically Activated SrTiO3: Photocatalytic H2 Evolution from Neutral Aqueous Methanol Solution in the Absence of Any Noble Metal Cocatalyst

Zhou X, Liu N, Yokosawa T, Osvet A, Miehlich M, Meyer K, Spiecker E, Schmuki P (2018)

Publication Language: English

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2018

Journal

ACS Applied Materials and Interfaces American Chemical Society

Publisher: American Chemical Society

Book Volume: 10

Pages Range: 29532-29542

Journal Issue: 35

DOI: 10.1021/acsami.8b08564

Abstract

Noble metal cocatalysts are conventionally a crucial factor in oxide-semiconductor-based photocatalytic hydrogen generation. In the present work, we show that optimized high-temperature hydrogenation of commercially available strontium titanate (SrTiO₃) powder can be used to engineer an intrinsic cocatalytic shell around nanoparticles that can create a photocatalyst that is highly effective without the use of any additional cocatalyst for hydrogen generation from neutral aqueous methanol solutions. This intrinsic activation effect can also be observed for SrTiO₃[100] single crystal as well as Nb-doped SrTiO₃[100] single crystal. For all types of SrTiO₃ samples (nanopowders and either of the single crystals), hydrogenation under optimum conditions leads to a surface-hydroxylated layer together with lattice defects visible by transmission electron microscopy, electron paramagnetic resonance (EPR), and photoluminescence (PL). Active samples provide specific defects identified by EPR, PL, and electron-energy loss spectroscopy as Ti³⁺ states in a defective matrix—this is in contrast to the inactive defects formed in other reductive atmospheres. In aqueous media, active SrTiO₃ samples show a significant negative shift of the flatband potential (in photoelectrochemical as well as in capacitance data) and a lower charge-transfer resistance for photoexcited electrons. We therefore ascribe the remarkable cocatalyst-free activation of the material to a synergy between thermodynamics (altered interface energetics induced by hydroxylation) and kinetics (charge transfer mediation by suitable Ti³⁺ states).

Authors with CRIS profile

Xuemei Zhou Lehrstuhl für Werkstoffwissenschaften (Korrosion und Oberflächentechnik) Ning Liu Lehrstuhl für Werkstoffwissenschaften (Korrosion und Oberflächentechnik) Tadahiro Yokosawa Lehrstuhl für Werkstoffwissenschaften (Mikro- und Nanostrukturforschung) Andres Osvet Institute Materials for Electronics and Energy Technology (i-MEET) Matthias Miehlich Lehrstuhl für Anorganische und Allgemeine Chemie Karsten Meyer Lehrstuhl für Anorganische und Allgemeine Chemie Erdmann Spiecker Lehrstuhl für Werkstoffwissenschaften (Mikro- und Nanostrukturforschung) Patrik Schmuki Lehrstuhl für Werkstoffwissenschaften (Korrosion und Oberflächentechnik)

Additional Organisation(s)

Interdisziplinäres Zentrum, Center for Nanoanalysis and Electron Microscopy (CENEM)

How to cite

APA:

Zhou, X., Liu, N., Yokosawa, T., Osvet, A., Miehlich, M., Meyer, K.,... Schmuki, P. (2018). Intrinsically Activated SrTiO3: Photocatalytic H2 Evolution from Neutral Aqueous Methanol Solution in the Absence of Any Noble Metal Cocatalyst. ACS Applied Materials and Interfaces, 10(35), 29532-29542. https://doi.org/10.1021/acsami.8b08564

MLA:

Zhou, Xuemei, et al. "Intrinsically Activated SrTiO3: Photocatalytic H2 Evolution from Neutral Aqueous Methanol Solution in the Absence of Any Noble Metal Cocatalyst." ACS Applied Materials and Interfaces 10.35 (2018): 29532-29542.

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