A tantalum nitride photoanode modified with a hole-storage layer for highly stable solar water splitting.

Photoelectrochemical (PEC) water splitting is an ideal approach for renewable solar fuel production. One of the major problems is that narrow bandgap semiconductors, such as tantalum nitride, though possessing desirable band alignment for water splitting, suffer from poor photostability for water oxidation. For the first time it is shown that the presence of a ferrihydrite layer permits sustainable water oxidation at the tantalum nitride photoanode for at least 6 h with a benchmark photocurrent over 5 mA cm(-2) , whereas the bare photoanode rapidly degrades within minutes. The remarkably enhanced photostability stems from the ferrihydrite, which acts as a hole-storage layer. Furthermore, this work demonstrates that it can be a general strategy for protecting narrow bandgap semiconductors against photocorrosion in solar water splitting.

[1]  Akio Ishikawa,et al.  Electrochemical Behavior of Thin Ta3N5 Semiconductor Film , 2004 .

[2]  Kazuhiko Maeda,et al.  Ta3N5 photoanodes for water splitting prepared by sputtering , 2011 .

[3]  J. Jambor,et al.  Occurrence and Constitution of Natural and Synthetic Ferrihydrite, a Widespread Iron Oxyhydroxide. , 1998, Chemical reviews.

[4]  Lianzhou Wang,et al.  Template-free synthesis of Ta3N5 nanorod arrays for efficient photoelectrochemical water splitting. , 2013, Chemical communications.

[5]  Lin-Wang Wang,et al.  Thermodynamic Oxidation and Reduction Potentials of Photocatalytic Semiconductors in Aqueous Solution , 2012, 1203.1970.

[6]  F. Fabregat‐Santiago,et al.  Interpretation of Cyclic Voltammetry Measurements of Thin Semiconductor Films for Solar Fuel Applications. , 2013, The journal of physical chemistry letters.

[7]  N. Lewis.  Toward Cost-Effective Solar Energy Use , 2007, Science.

[8]  Michael Grätzel,et al.  The Transient Photocurrent and Photovoltage Behavior of a Hematite Photoanode under Working Conditions and the Influence of Surface Treatments , 2012 .

[9]  J. A. Seabold,et al.  Effect of a Cobalt-Based Oxygen Evolution Catalyst on the Stability and the Selectivity of Photo-Oxidation Reactions of a WO3 Photoanode , 2011 .

[10]  Juan Bisquert,et al.  Photoelectrochemical and impedance spectroscopic investigation of water oxidation with "Co-Pi"-coated hematite electrodes. , 2012, Journal of the American Chemical Society.

[11]  Kyoung-Shin Choi,et al.  A new electrochemical synthesis route for a BiOI electrode and its conversion to a highly efficient porous BiVO4 photoanode for solar water oxidation , 2012 .

[12]  Tao Yu,et al.  A co-catalyst-loaded Ta(3)N(5) photoanode with a high solar photocurrent for water splitting upon facile removal of the surface layer. , 2013, Angewandte Chemie.

[13]  Juan Bisquert,et al.  Electrochemical and photoelectrochemical investigation of water oxidation with hematite electrodes , 2012 .

[14]  Allen J. Bard,et al.  Amorphous FeOOH oxygen evolution reaction catalyst for photoelectrochemical water splitting. , 2014, Journal of the American Chemical Society.

[15]  James R. McKone,et al.  Solar water splitting cells. , 2010, Chemical reviews.

[16]  Jingying Shi,et al.  Microwave-assisted hydrothermal synthesis of perovskite NaTaO3 nanocrystals and their photocatalytic properties , 2012 .

[17]  Kyoung-Shin Choi,et al.  Efficient and stable photo-oxidation of water by a bismuth vanadate photoanode coupled with an iron oxyhydroxide oxygen evolution catalyst. , 2012, Journal of the American Chemical Society.

[18]  K. Domen,et al.  Vertically Aligned Ta3N5 Nanorod Arrays for Solar‐Driven Photoelectrochemical Water Splitting , 2013, Advanced materials.

[19]  A. Ambrosini,et al.  Ordered ferrimagnetic form of ferrihydrite reveals links among structure, composition, and magnetism , 2010, Proceedings of the National Academy of Sciences.

[20]  Juan Bisquert,et al.  Water oxidation at hematite photoelectrodes: the role of surface states. , 2012, Journal of the American Chemical Society.

[21]  M. Lyons,et al.  An electrochemical impedance study of the oxygen evolution reaction at hydrous iron oxide in base. , 2013, Physical chemistry chemical physics : PCCP.

[22]  Allen J. Bard,et al.  Synthesis of Ta3N5 Nanotube Arrays Modified with Electrocatalysts for Photoelectrochemical Water Oxidation , 2012 .

[23]  L. Peter.  Energetics and kinetics of light-driven oxygen evolution at semiconductor electrodes: the example of hematite , 2013, Journal of Solid State Electrochemistry.

[24]  Tao Yu,et al.  Co3O4 Nanoparticles as Robust Water Oxidation Catalysts Towards Remarkably Enhanced Photostability of a Ta3N5 Photoanode , 2012 .

[25]  M. Grätzel,et al.  Probing the photoelectrochemical properties of hematite (α-Fe2O3) electrodes using hydrogen peroxide as a hole scavenger , 2011 .

[26]  M. Schoonen,et al.  The Structure of Ferrihydrite, a Nanocrystalline Material , 2007, Science.

[27]  M. Tomkiewicz.  The Potential Distribution at the TiO2 Aqueous Electrolyte Interface , 1979 .

[28]  S. Jiao,et al.  Cobalt-bilayer catalyst decorated Ta3N5 nanorod arrays as integrated electrodes for photoelectrochemical water oxidation , 2013 .

[29]  I. E. Grey,et al.  Efficiency of solar water splitting using semiconductor electrodes , 2006 .

[30]  D. Gamelin,et al.  Near-complete suppression of surface recombination in solar photoelectrolysis by "Co-Pi" catalyst-modified W:BiVO4. , 2011, Journal of the American Chemical Society.

[31]  A. Fujishima,et al.  Electrochemical Photolysis of Water at a Semiconductor Electrode , 1972, Nature.

[32]  Akio Ishikawa,et al.  Conduction and Valence Band Positions of Ta2O5, TaON, and Ta3N5 by UPS and Electrochemical Methods , 2003 .

[33]  O. Terasaki,et al.  Cobalt phosphate-modified barium-doped tantalum nitride nanorod photoanode with 1.5% solar energy conversion efficiency , 2013, Nature Communications.

[34]  Robert Kostecki,et al.  Nanomaterials for renewable energy production and storage. , 2012, Chemical Society reviews.

[35]  Kyoung-Shin Choi,et al.  Nanoporous BiVO4 Photoanodes with Dual-Layer Oxygen Evolution Catalysts for Solar Water Splitting , 2014, Science.