Recently, M. Rajagopalan, a grade seven student at the 2023 California Science and Engineering Fair (CSEF), wanted to produce hydrogen on demand without the need for an external source of energy. He chose to make aluminum nanoparticles from a gallium-aluminum composite for water splitting and hydrogen generation. Normally, aluminum has a surface barrier layer of aluminum oxide (Al2O3) which prevents it from reacting with water to form hydrogen gas. Gallium disrupts this barrier layer and allows the aluminum particles to interact with water to produce hydrogen.
The study showed that distilled water gave better results compared to salty sea water: namely higher yield and quicker reaction times, in minutes instead of hours. The future goal is to use this on-demand hydrogen to produce electricity, to power small vehicles or make clean drinking water for use during emergencies. For a full length report on this type of methodology, see “Aluminum Nanoparticles from a ga–al composite…” published on the American Chemical Society website.
It is unfortunate that seawater contains substances that interfere with the generation of hydrogen, since seawater is so abundant globally. Luckily, this year at the International Science and Engineering Fair (ISEF) in Texas, F. Almuhaysh, a high school student from Saudi Arabia, is presenting his research on how to get rid of this problem. His study on a metal-organic framework-based (MOF) electrocatalyst for seawater splitting shows that his approach solves the problem of chlorine in seawater; and that it's also a more efficient and less expensive alternative to platinum for hydrogen evolution reactions (HER).
Also at this year's ISEF competition, is a presentation by Sander Simson from Tallinn, who is one of two students representing Estonia at this year's ISEF competition. His hydrogen fuel cell research has focused on the use of coffee grounds as a support for platinum catalysis. An important aim of these experiments is to reduce costs as well as improve fuel cell performance. His research has recently been featured on err.ee.
While green hydrogen research is an exciting wave of change for the future, there are two other research trends that are noteworthy for high school students interested in environmental studies. One is the use of calcium carbonate (egg shells) to reduce heavy metal contamination in public water supplies. The second is the study of green roofs and urban forestry, to reduce heat islands in urban environments.
When heavy metals such as zinc, manganese, and copper interact with calcium carbonate, an ion exchange reaction occurs. The poorly soluble metal carbonate products precipitate, removing them from the water supply. Oyster and egg shells are examples of readily available natural products which are almost 100% pure calcium carbonate. At CSEF 2023, students Nguyen, Ngo, and Lopez showed that using porous concrete bricks manufactured to contain pulverized oyster or egg shell pieces was effective in removing heavy metals from contaminated water samples. Results showed that higher calcium carbonate content and smaller particle size produced better results. Read “Role of calcium carbonate in the process of heavy metal…” (Wierzba S. et al., [2022]) on nature.com for similar studies.
For students interested in green roofs and urban forestry to reduce heat islands in urban environments, “Landscape and vegetation traits of urban green space…” published on ScienceDirect is also useful reading.
In the meantime, have a happy summer full of exploration and discovery!
