Self-Enhancing H2 Evolution from TiO2 Nanostructures under Illumination.

Illumination of anatase in an aqueous methanolic solution leads to the formation of Ti3+ sites that are catalytically active for the generation of dihydrogen (H2 ). With increasing illumination time, a light-induced self-amplification of the photocatalytic H2 production rate can be observed. The effect is characterized by electron paramagnetic resonance (EPR) spectroscopy, reflectivity, and photoelectrochemical techniques. Combined measurements of H2 generation rates and in situ EPR spectroscopic observation over the illumination time with AM 1.5G or UV light establish that the activation is accompanied by the formation of Ti3+ states, which is validated through their characteristic EPR resonance at g=1.93. This self-activation and amplification behavior can be observed for anatase nanoparticles and nanotubes.

[1]  A. Naldoni,et al.  Photocatalysis with Reduced TiO2: From Black TiO2 to Cocatalyst-Free Hydrogen Production , 2018, ACS catalysis.

[2]  K. Kimoto,et al.  Homogeneous Electron Doping into Nonstoichiometric Strontium Titanate Improves Its Photocatalytic Activity for Hydrogen and Oxygen Evolution , 2018, ACS Catalysis.

[3]  R. Zbořil,et al.  Semimetallic core-shell TiO2 nanotubes as a high conductivity scaffold and use in efficient 3D-RuO2 supercapacitors , 2017 .

[4]  P. Schmuki,et al.  Photoelectrochemical H2 Generation from Suboxide TiO2 Nanotubes: Visible-Light Absorption versus Conductivity. , 2017, Chemistry.

[5]  W. Peukert,et al.  Noble‐Metal‐Free Photocatalytic Hydrogen Evolution Activity: The Impact of Ball Milling Anatase Nanopowders with TiH2 , 2017, Advanced materials.

[6]  P. Schmuki,et al.  Black Magic in Gray Titania: Noble-Metal-Free Photocatalytic H2 Evolution from Hydrogenated Anatase. , 2017, ChemSusChem.

[7]  M. Hartmann,et al.  Hydrogenated anatase: strong photocatalytic dihydrogen evolution without the use of a co-catalyst. , 2014, Angewandte Chemie.

[8]  Y. Horiuchi,et al.  Understanding TiO2 photocatalysis: mechanisms and materials. , 2014, Chemical reviews.

[9]  P. Schmuki,et al.  One-dimensional titanium dioxide nanomaterials: nanotubes. , 2014, Chemical reviews.

[10]  H. Fu,et al.  Ordered mesoporous black TiO(2) as highly efficient hydrogen evolution photocatalyst. , 2014, Journal of the American Chemical Society.

[11]  A. Selloni,et al.  Theoretical studies on anatase and less common TiO2 phases: bulk, surfaces, and nanomaterials. , 2014, Chemical reviews.

[12]  M. Hartmann,et al.  Black TiO2 nanotubes: cocatalyst-free open-circuit hydrogen generation. , 2014, Nano letters.

[13]  K. Maeda,et al.  Dependence of Activity of Rutile Titanium(IV) Oxide Powder for Photocatalytic Overall Water Splitting on Structural Properties , 2014 .

[14]  H. Idriss,et al.  Photoreaction of Au/TiO2 for hydrogen production from renewables: a review on the synergistic effect between anatase and rutile phases of TiO2 , 2012, Materials for Renewable and Sustainable Energy.

[15]  M. Marelli,et al.  Effect of nature and location of defects on bandgap narrowing in black TiO2 nanoparticles. , 2012, Journal of the American Chemical Society.

[16]  Patrik Schmuki,et al.  TiO2‐Nanoröhren: Synthese und Anwendungen , 2011 .

[17]  Patrik Schmuki,et al.  TiO2 nanotubes: synthesis and applications. , 2011, Angewandte Chemie.

[18]  Xiaobo Chen,et al.  Increasing Solar Absorption for Photocatalysis with Black Hydrogenated Titanium Dioxide Nanocrystals , 2011, Science.

[19]  Kaixue Wang,et al.  Light-induced formation of porous TiO2 with superior electron-storing capacity. , 2010, Chemical communications.

[20]  B. Hameed,et al.  The advancements in sol–gel method of doped-TiO2 photocatalysts , 2010 .

[21]  A. Fujishima,et al.  TiO2 photocatalysis and related surface phenomena , 2008 .

[22]  K. Sumathy,et al.  A review and recent developments in photocatalytic water-splitting using TiO2 for hydrogen production , 2007 .

[23]  O. Dulub,et al.  THE RELATIONSHIP BETWEEN BULK AND SURFACE PROPERTIES OF RUTILE TiO2(110) , 2000 .

[24]  Akira Fujishima,et al.  Titanium dioxide photocatalysis , 2000 .

[25]  J. Yates,et al.  Photocatalysis on TiO2 Surfaces: Principles, Mechanisms, and Selected Results , 1995 .

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

[27]  C. Renz.  Lichtreaktionen der Oxyde des Titans, Cers und der Erdsäuren , 1921 .