Modern society depends on a continuous, reliable supply of energy that must be available both day and night. At the moment, the burning of carbon-based fossil fuels such as coal and oil provide the overwhelming majority of the world’s current, and projected, energy needs.
The problem rushing headlong towards us is that fossil fuels are non-renewable, and the burning of them leads to ever-increasing levels of pollution as well as a systematic increase in the level of greenhouse gases such as carbon dioxide (CO2) in our atmosphere. This, in turn, leads to human-induced climate change.
A major challenge facing the world is to develop sustainable, non-carbon-based sources of energy. One of the most obvious, renewable and non-carbon-based sources of energy is sunlight. Given that sunlight is only available for part of the day, the task is how to capture and store that solar energy in a form that can be used at a later time and on a large-enough scale.
One approach is to efficiently convert solar energy into the chemical energy stored in chemical bonds, such as gaseous hydrogen (H2) and oxygen (O2), via the splitting of water (H2O). This water splitting reaction is accomplished via photosynthesis in nature.
Hydrogen and oxygen are the dream fuels of the environmentally conscious engineer. They can, for example, be combined in a fuel cell to produce...
