Hydrogen has been touted as an environmentally friendly wonder fuel that can be used in vehicles and burns to produce only water as a by product. The problem with hydrogen is that producing it is far from environmentally friendly and storing it in a fuel tank is extremely hazardous. Researchers are turning to nanotechnology to overcome these problems.
How Hydrogen Works As A Fuel
The burning of hydrogen is a very simple chemical reaction. The hydrogen combines with oxygen from the air to give energy in the form of heat and the waste product is pure water. The idea of being able to run cars on water as the fuel is a myth. Water is effectively the ‘ash’ caused by the burning of hydrogen.
Two main methods are used to produce hydrogen. Steam reforming and electrolysis, both of which present environmental issues.
Steam reforming or Steam Methane Reforming (SMR) reacts methane with steam at high temperature in the presence of a catalyst to give hydrogen and carbon monoxide. From an environmental position this method is still generating unacceptably significant quantities of greenhouse gases.
Electrolysis is the process of passing electricity through something to break it into component elements or molecules. The electrolysis of water breaks it down into pure hydrogen and pure oxygen. Although this process doesn’t produce any environmentally harmful by products, the predominant way of producing electricity is through the burning of fossil fuels.
Solar Energy and Hydrogen Production
One way of producing environmentally friendly hydrogen is by electrolysis with the electricity generated via solar cells. A great deal of research is underway into using nanotechnology to produce solar electricity at greater efficiencies and with cheaper components. Another method is photoelectrochemical hydrogen production cells.
Photoelectrochemical (PEC) cells are being developed by nanotechnologists to produce hydrogen in an environmentally friendly manner. In one of these systems semiconducting nanoparticles, like titanium dioxide, are placed on a conducting glass substrate and the glass attached to an electrode. Between the glass plate and electrode is water. Incident light causes electrons to move from the nanoparticles, to the electrode. This strips electrons from the water, breaking the water molecules and releasing hydrogen.