A team of researchers at MIT has just announced that they have successfully modified a virus to split apart molecules of water, paving the way for an efficient and non-energy intensive method of producing hydrogen fuel. The team engineered a common, harmless bacterial virus to assemble the components needed to crack apart a molecule of water, yielding a fourfold boost in efficiency over similar processes.
Hydrogen has a lot of potential as an alternative fuel – it can be used in fuel cells to trigger a chemical reaction that generates carbon-free electricity, and the only byproducts are waste heat and water. However as of right now, most methods of generating hydrogen are either extremely energy intensive or utilize methane and release greenhouse gases into the atmosphere.
Taking inspiration from the way that plants use sunlight to split water into hydrogen and oxygen, the MIT team led by Angela Belcher genetically engineered a virus called M13 to act as a sort of “scaffolding” structure that enables a remarkably efficient hydrogen-producing chemical reaction. When introduced to a catalyst (iridium oxide) and a biological pigment (zinc porphyrins), the viruses formed wire-like structures that efficiently split water into oxygen and hydrogen. The pigment captures light from the sun, and the catalyst splits the molecule.
Photo by Fernando H
According to MIT, “the viruses simply act as a kind of scaffolding, causing the pigments and catalysts to line up with the right kind of spacing to trigger the water-splitting reaction. The role of the pigments is to act as an antenna to capture the light, Belcher explains, and then transfer the energy down the length of the virus, like a wire. The virus is a very efficient harvester of light, with these porphyrins attached.”
Over time the structure of these virus wires start to lose their effectiveness, so the researchers encapsulated them in a “microgel matrix” that holds their alignment steady. Once the viruses have produced hydrogen it could be used to generate electricity in a fuel cell or to make liquid fuels for cars and trucks.
Currently the team is working on refining the process and finding a replacement for the relatively costly iridium catalyst used in the study. They also need to find a way to transform the products of the reaction into usable hydrogen fuel – currently the hydrogen atoms are split into constituent protons and electrons that must be recombined into complete atoms and molecules. Within two years Belcher expects to have a prototype device that can split water into oxygen and hydrogen using a self-sustaining system.
Lead photo by Dominick Reuter