Photohydrogen Production Using Tandem Cell

Today, hydrogen is primarily used as a chemical feedstock in the petrochemical, food,
electronics, and metallurgical processing industries. It is also rapidly emerging as a
major component in clean sustainable energy systems. Although hydrogen is considered
clean energy, its most practiced production method, steam reforming of natural gas
releases large amounts of carbon dioxide into the atmosphere, promoting the greenhouse
effect and global warming. Among the alternative methods of production that scientists
are delving into are photocatalytic reactions. However, the efficiency and availability of
photocatalysts which can be activated by the solar spectrum or reduced sunlight
conditions is limited. Thus, the aim of this study is to investigate and develop the
process of photohydrogen production using tandem cell in order to allow improved
absorption of the visible region of sunlight. Two types of photocatalysts, copper-doped
and iron-doped titania are used in this experiment, each with three different weight
loadings. The photocatalysts were prepared using precipitation method. After
preparation, the photocatalysts are characterized using the Diffuse Reflectance UV-Vis
(DRS), the X-Ray Diffractometer (XRD), the Field Emission Scanning Electron
Microscope (FESEM) and the Fourier Transform Infra-Red (FTIR) Spectra. The results
of these analyses are included in the report. The tandem cell is constructed and reaction
studies using the photocatalysts and the tandem cell are conducted. The reaction studies
are done to observe the amount of hydrogen produced from distilled water and seawater,
and to see the performance of each photocatalyst in comparison with the tandem cell
setup. From the reaction studies, 5wt% Cu-Ti02 and 1.5wt% Fe-Ti02 are found to
exhibit the best performance and are used in comparison with the tandem cell setup.
Upon comparison, it is found that although the tandem cell falls short of the copper
doped catalyst in terms of hydrogen production, it exceeds the performance of the ferum
doped catalyst significantly. It can be concluded that the tandem cell is applicable in
photohydrogen production, thus the project objective is achieved.