Fabrication of P-type Cu2O and N-type Fe2TiO5 Photoelectrodes for Solar Hydrogen Application
Po-Yang Peng1*, Yan-Gu Lin1, Yu-Hsueh Chang1, Yu-Chang Lin1,2, San-Yuan Chen2
1Materials Science Group, National Synchrotron Radiation Research Center, Hsinchu, Taiwan
2Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan
* presenting author:PoYang PENG, email:thepoyang@gmail.com
In this work we present an active photoelectrodes for solar H2 production, consisting P-type cuprous oxide (Cu2O) and N-type of Ti-containing hematite (Fe2TiO5), respectively. Electrodeposition approach was used to fabricate Fe2TiO5 nanostructured films and Cu2O nanoparticle film using ZnO nanorods as a sacrificial scaffold was fabricated, respectively. The morphology and microstructure of photoelectrodes were examined at each stage with a scanning electron microscope, X-ray diffraction, Raman spectra, and X-ray photoelectron spectra. For Cu2O, the energy bandgap was confirmed to be 2.03 eV from IPCE; the carrier concentration 4×102cm3 and flat-band potential 0.02 V were determined from a Mott-Schottky plot. This Fe2TiO5 increased the carrier concentration about ten-fold, confirmed with a Mott-Schottky analysis; and the photocurrent enhanced four-fold relative to pristine hematite. Synchrotron-based soft X-ray absorption spectra clearly revealed that a local Fe2TiO5 structure in hematite formed a heterojunction, which decreased the accumulation of photogenerated holes and improved the performance. These nanostructures synthesized can not only illustrate a great prospect for solar generation of hydrogen but also offer a blueprint for the future design of photocatalysts.

Keywords: Iron oxide, Zinc oxide, Copper(I) oxide, Nanostructured film, Photoelectrochemical