You’re sitting in stand still traffic. Your car’s fuel level is reaching empty and you’re five miles away from the nearest gas station. But wait, you remember you have a couple bottles of water in the back of your car. Yes, you read that right, water. The California Institute of Technology (Caltech) and Berkeley Labs have combined in a joint effort to search for possible alternatives to fossil fuels.
In a recent study published in the journal Proceedings of the National Academy of Sciences, researchers have shown that a possible alternative may be found in solar fuels, synthetic chemical fuels comprised of sunlight, water, and carbon dioxide.
How is it that these readily available and renewable resources could power a car? Well, the answer is artificial photosynthesis. Photosynthesis is the process by which plants use sunlight to extract energy from water and carbon dioxide.
During photosynthesis, water is split into its component parts– two hydrogen molecules and one oxygen molecule. In theory, these two hydrogen molecules can then be reunited to create a highly flammable hydrogen gas or combined with carbon dioxide to create a hydrocarbon fuel. But there’s a problem.  
Water does not spontaneously decompose when light shines on it. It requires a catalyst or accelerator to harvest the energy in light to break the water down into its component parts. Scientists refer to these catalysts as photoanodes. In plants the catalyst is chlorophyll, which gives them their green color. 
The researchers at CalTech and Berkley have now discovered 12 new photoanodes.  To identify them, the researchers spray different combinations of elements onto thin plates and place them into a thermal energy machine to see which ones can absorb sunlight. 
Once these materials have been isolated, the next task at hand is to determine which ones can efficiently convert solar energy into chemical reactions that generate fuel. Caltech and Berkely have created a new technology that accelerates this discovery process by 100 to 1,000 times. 
The finding is important because few photoanode materials have been discovered due to the time consumption of the traditional discovery methods.  Over the past 40 years researchers have identified only 16 possible catalysts. 
The discovery of more possible photoanodes suggests the very real possibility that our cars could be running on water in the near future. The implications of this discovery could prove to be monumental for the future of the environment and the attrition of climate change.