Photoelectrolysis of water in cells with SrTiO3 anodes

Mavroides, J. G.; Kafalas, J. A.; Kolesar, D.F.

doi:10.1063/1.88723

Cited by 341 publications

(138 citation statements)

References 5 publications

Supporting

Mentioning

130

Contrasting

Unclassified

Order By: Relevance

“…17,[21][22][23][24][25][26][27][28] As a model system we use single crystalline nanoparticles of Rh-doped SrTiO 3 . SrTiO 3 is an established photocatalyst for overall water splitting under UV light only, 18,21,[29][30][31] but it can be converted into a visible light responsive material upon doping with Cr, 32 Cr/Sb, 33,34 Cr/Ta, 35 Rh, 36,37 Ni/Ta, 38 and…”

Section: Introductionmentioning

confidence: 99%

Photochemical charge transfer observed in nanoscale hydrogen evolving photocatalysts using surface photovoltage spectroscopy

Wang

Zhao

Osterloh

2015

Energy Environ. Sci.

View full text Add to dashboard Cite

The application of inorganic nanostructures for solar water splitting is currently limited by our understanding of photochemical charge transfer on the nanoscale, where space charge layers are less effective for carrier separation. Here we employ surface photovoltage spectroscopy to measure the internal photovoltages in single crystalline platinum/ruthenium-modified Rh-doped SrTiO 3 nanocrystals for the first time. Voltages of À0.88 V and À1.13 V are found between the absorber and the Ru and Pt cocatalysts, respectively, and a voltage of À1.48 V for a Rh:SrTiO 3 film on an Au substrate. This shows that the Pt and Ru cocatalysts not only improve the redox kinetics but also aid charge separation in the absorber. Voltages of +0.4 V, +0.6 V, and +1.2 V are found for hole injection into KI, K 4 [Fe(CN) 6 ], and methanol, respectively, and a voltage of À0.7 V for electron injection into K 3 [Fe(CN) 6 ]. These voltages correlate well with the photocatalytic performance of the catalyst; they are influenced by the built-in potentials of the donor-acceptor configurations, the physical separation of donors and acceptors, and the reversibility of the redox reaction.The photovoltage data also allowed the identification of a photosynthetic system for hydrogen evolution (80 mmol g À1 h À1) under visible light illumination (4400 nm) from 0.05 M aqueous K 4 [Fe(CN) 6 ]. Broader contextNanostructured light absorbers have advantages for solar water splitting, including shortened carrier collection pathways and improved light distribution. However, the application of nanoscale absorbers for artificial photosynthesis is currently limited by our understanding of photochemical charge transfer on the nanoscale, where space charge layers are not effective for charge separation. Here we employ surface photovoltage spectroscopy (SPS) to observe electron and hole transfer from single crystalline platinum/ruthenium-modified Rh-doped SrTiO 3 nanocrystals for the first time. We find that the absorber-Pt/Ru junctions promote electron-hole separation strongly, allowing open circuit voltages of over 1.0 V. This is comparable to the effect of molecular redox reagents at the absorber surfaces. Overall, we find that nanoscale charge transfer is controlled by the built-in potentials of the absorber/acceptor configuration, by the spatial separation between donors and acceptors and by the reversibility of the redox reactions. These observations aid the understanding of photochemical charge transfer on the nanoscale and contribute to the design of more efficient systems for artificial photosynthesis.

show abstract

Section: Introductionmentioning

confidence: 99%

Photochemical charge transfer observed in nanoscale hydrogen evolving photocatalysts using surface photovoltage spectroscopy

Wang

Zhao

Osterloh

2015

Energy Environ. Sci.

View full text Add to dashboard Cite

show abstract

“…In contrast, the position of the conduction band is usually in the spotlight, since its edge is very close to the HER potential. In the case of SrTiO 3 it is only about -200 mV more negative [4]. Figure 1a illustrates that a freely moving electron would not be able to perform the HER, although the semiconductor fulfills the aforementioned requirements.…”

Section: Theoreticalmentioning

confidence: 99%

“…SrTiO 3 is a perovskitetype semiconductor and possesses excellent stability properties in alkaline media under illumination [2]. Furthermore, it exhibits adequate band positions and a large band gap to split water into hydrogen and oxygen without any additional bias voltage [3]. At first, we discuss the influence of light intensity on the energy levels of a PEC with electrolyte-metal-semiconductorelectrolyte interfaces and then show photocurrent density, external quantum efficiency (EQE) and open circuit potential (OCP) measurements of the presented PECs under different 375 nm illumination intensities.…”

Section: Introductionmentioning

confidence: 99%

Light Intensity Influence on Strontium Titanate Based Photo- Electrochemical Cells

Hertkorn¹

2017

Ceramics - Silikaty

View full text Add to dashboard Cite

The influence of light intensity on photo-electrochemical cells (PECs) consisting of an n-type strontium titanate (SrTiO 3 ) photoanode and nickel cathode in potassium hydroxide electrolyte is studied. The band levels of an electrolyte-metalsemiconductor-electrolyte system are presented and the effect of different light intensities on the energy levels is investigated. Photocurrent density, quantum efficiency, and open circuit potential measurements are performed on the processed PECs under different light intensities (375 nm). It is demonstrated that a threshold value of the light intensity has to be reached inorder to obtain positive photo activity and that beyond this value the performance remains nearly constant.

show abstract

“…Both powdered and electrode photocatalysts of this type have been thoroughly investigated. [27][28][29][30][31] However, very few of these systems achieved spontaneous (i.e. no applied bias) water-splitting using visible illumination and thus had very low STH conversion efficiencies.…”

Section: History Of Solar-driven Photoelectrochemical (Pec) Water Splmentioning

confidence: 99%

Experimental demonstrations of spontaneous, solar-driven photoelectrochemical water splitting

Ager

Shaner

Walczak

et al. 2015

Energy Environ. Sci.

558

456

View full text Add to dashboard Cite

show abstract

Photoelectrolysis of water in cells with SrTiO3 anodes

Cited by 341 publications

References 5 publications

Photochemical charge transfer observed in nanoscale hydrogen evolving photocatalysts using surface photovoltage spectroscopy

Photochemical charge transfer observed in nanoscale hydrogen evolving photocatalysts using surface photovoltage spectroscopy

Light Intensity Influence on Strontium Titanate Based Photo- Electrochemical Cells

Experimental demonstrations of spontaneous, solar-driven photoelectrochemical water splitting

Contact Info

Product

Resources

About