Solar Energy Activity Laboratory (SEAL) and the Solar Hydrogen Activity research Kit (SHArK) Projects: A New Paradigm for Laboratory Experiment and Global Problem Solving.
|Identifying and developing new renewable energy sources are a top priority for mankind. Solar energy is the only available source of energy capable of continually providing the vast quantities of carbon-free energy that can meet the growing global energy demand. Photoelectrolysis of water with sunlight to produce hydrogen solves the problem of intermittent and unevenly distributed sunlight by storing the solar energy in a form that can be transported to provide fuel for combustion or a future generation of fuel cell vehicles and for electricity generation at night. |
The SHArK Project was established in 2008 at University of Wyoming as a spinoff of Professor Bruce Parkinson’s research effort on solar water splitting. The SEAL Project was established in 2011 at Caltech as part of the NSF Center for Chemical Innovation outreach efforts. These projects provides a unique approach to learning chemistry that engages young people to participate in actual research to help solve the global energy problem.
The goal is to discover metal oxide semiconductors that can split water into hydrogen and oxygen using sunlight. Currently, no known stable semiconductor is capable of efficiently and inexpensively photoelectrolyzing water with sunlight. There are about 60 metals in the periodic table, and when combined in different ratios to create semiconductors could result in millions of different combinations to test. Young people in high schools and colleges across the country are being recruited in a “Solar Army” to help solve this problem.
The initial SHArK Kits using inexpensive commercially available materials like laser pointers and LEGOs® were developed that allow young scientist to produce and test different potential materials for their ability to photoelectrolyze water. The SEAL Kits were a simplified more robust kit that allowed their use in many more locations. Materials are deposited onto a glass substart that has a transparent conduction film by pipetting (drop-wise). Subsequent firing of the substrates at 500°C produced patterns of mixed metal oxides. The substrate with the metal oxide film is then immersed into an electrochemical cell containing an electrolyte solution. A light box with 64 diodes that are aligned with the pattern of the drops is used to illumate the metal oxide spots and measuring the photocurrent as a function of position. The results are displayed as a false color image of the photoelectrolysis activity in the metal oxide “library”. False color representations of the photocurrent data reveal spots, associated with a particular composition, that have photoelectrolysis activity greater to produce oxygen. (see figure 1) Results from the scans are posted in a database that can be accessed by any registered participant with the project.
After an initial testing stage, the SHArK project was included as a component of outreach in the multi-institutional NSF-funded Center for Chemical Innovation (CCI) entitled “CCI Solar”. Dr. Harry Gray, the director of the CCI Solar project, has given many talks about the kits and has proselytized their use. As the project grew it became clear that the original kits lacked the robustness required to be used in all the various settings and with all the different levels of students that wanted to use them. Thus Dr. Jay Winkler developed the SEAL kits to expand the program. Currenlty (summer of 2012) over 70 sites world wide are using the kits.
While one of the most effective way to attract kids to science is through participation in real scientific projects, very few high-school students have this opportunity. Moreover often when they are available they are restricted to the brightest students at the best high schools. The broader aim of the SEAL project is to bring this research to every high school and offer all students, regardless of their socio-economic background, the chance to participate in the project.