B.Sc./M.Sc. project
2012-13
Fabrication of Novel Photoanodes for Photoelectrochemical Water Splitting
The sun provides a vast reservoir of energy to the earth every day in the form of photons/light.
A critical challenge in the 21st century is to be able to convert this solar energy into useful electrical
energy or fuels. One of the most promising methods to convert solar energy into fuels is through
photoelectrochemical water splitting over semi-conductor photoanodes. The most important factor in
this reaction is the absorption of light and catalytic activity of the semi-conductor photoanode. Many
materials have been used for this purpose, but there exist significant draw backs such as large band
gap energies, photostability, and the placement
of the valence and conduction band energies.
Therefore, new materials need to be studied
which
have
promising
opto-electronic
properties that should be suitable for solar
water splitting reactions.
One such material that has recently
been investigated is CuWO4. CuWO4 has
shown n-type conductivity and a band gap of
2.25 eV, making it suitable for visible light
absorption. In some cases, p-type conductivity
has been reported for amorphous CuWO4,
which is an interesting feature that would allow
for a CuWO4(n)-CuWO4(p) homojunctions. An advantage of this material is that it has enhanced
photostability compared to pure Cu2O and even WO3. However, CuWO4 has produced only modest
photocurrent generation (~0.1 mA/cm2), which is far below the theoretical limit for a material with
such a band gap. In addition, since CuWO4 is a new material for photocatalytic applications, its optoelectronic properties have not been well studied or
understood by the scientific community. Therefore,
there is significant room for improving the charge
generation and transport properties in the material
through advanced materials engineering, while
taking advantage of its intrinsic photostability during
photoreactions.
During this work, you will evaluate different
methods for the preparation of CuWO4 thin films and
nanostructures by electro-deposition and solution-based
spray pyrolysis. You will then characterize the film
properties by X-Ray Diffraction (XRD), scanning
electron microscopy (SEM), and UV-Vis spectroscopy
in order to determine the crystal structure, morphology, and optical properties of the materials. Last,
you will probe the photocatalytic properties of CuWO4 films via photoelectrochemistry (PEC) to
measure the current generation, electronic properties, and photostability under solar irradiation.
Interested? Please contact Dr. Wilson Smith W.Smith@tudelft.nl
Key words: Solar water splitting, Nano-materials, Photo-electrochemistry, UV-vis
spectroscopy, X-Ray diffractometry, Solar Fuel generation