When talking about CO2, you don’t think much about renewable energy. If anything, you think about a type of fossil fuel that is pumping out additional greenhouse gases into the atmosphere leading to even adverse effects of global warming.
However, plants (all green-leafed plants) use CO2 and sunlight to make energy. Meaning CO2 is an input to the flora species biochemical processes. However, their intake of CO2 is at such a slow rate when compared to the rate at which mankind activities is pumping out CO2 into the atmosphere.
If plants could somehow match their intake of CO2 to the rate at which mankind activities produces it. Then the issue of global warming due to the greenhouse effect of CO2 would not be a problem.
Therefore, it should be a cause for celebration that a group of scientists from the University of Illinois at Chicago (UIC) have developed solar cells that convert atmospheric CO2 into fuel. In other words, they have come up with an artificial leaf (manmade leaf).
“The new solar cell is not photovoltaic; it’s photosynthesis,” said Amin Salehi-Khojin, an assistant professor of Mechanical and Industrial Engineering at UIC. “Instead of producing energy in an unsustainable one-way route from fossil fuels to greenhouse gas, we can now reverse the process and recycle atmospheric carbon into fuel using sunlight.”
The said solar cells work by removing CO2 from the atmosphere; just like green plants. Meaning mankind now has artificial leaves, which can produce energy-dense fuel in an efficient manner. The fuel produced is “synthesis gas; a mixture of hydrogen gas and carbon monoxide,” according to the UIC site. This synthesis gas can be burnt directly as fuel, or further processed to make diesel or other forms of hydrocarbon fuels.
The skills and technology for converting CO2 into burnable fuel have been around for quite a while. However, the process in and by itself is quite inefficient and requires the use of precious metals such as silver.
In contrast, the synthesis gas produced by the UIC researchers’ solar cells only need nanoflake tungsten diselenide to turn CO2 into burnable fuel. This material is 20 times cheaper than silver and 1,000 times more efficient as a catalyst during the chemical reaction process.
CO2 Greenhouse Effect
When talking about greenhouse gases and their effect on global warming, CO2 gas comes up more often in the conversation. Well even water vapour is a greenhouse gas, but you don’t often hear about it (if at all) compared to CO2. That is because CO2 is a deadly greenhouse gas; it stays much longer in the atmosphere compared to other greenhouse gases.
Additionally, CO2 is consistently and continuously being pumped into the atmosphere by human activities. Therefore its effect in global warming is more pronounced than the other greenhouse gases.