| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 726848 | Materials Science in Semiconductor Processing | 2013 | 7 Pages |
We describe in the present work the photo-electrochemical characterization of iron/folded-sheets mesoporous materials (Fe-FSM-16, Si/Fe=60) synthesized by microwave-assisted hydrothermal (M-H) method and its application for the hydrogen evolution upon visible light. The mesoporous catalyst consists of small Fe2O3 particles (∼2 nm) spread on SiO2 with specific surface area of ∼800 m2 g−1. The capacitance measurements reveal an iron deficiency and the oxide exhibit p type conductivity with activation energy of 0.07 eV. The optical gap of the hematite (α-Fe2O3) is evaluated at 3.24 eV from the diffuse reflectance spectrum. The flat band potential Vfb (−0.54 VSCE) and the holes density ND (9.56×1014 cm−3) of the hematite are obtained respectively by extrapolating the linear part to C−2=0 and the slope of the Mott Schottky plot. At pH=7, the conduction band (−0.47 VSCE) is suitably positioned with respect to the H2O/H2 level (−0.59 VSCE) leading to a spontaneous water reduction. The oxide is stabilized by hole consumption involving SO32− and S2O32− species and spectacular improvement of the hydrogen evolution is reported with evolution rates of ∼461 and 163 μ mol respectively.
