Man-Made Leaf that uses CO2 + Sunlight to produce Fuel

When talking about CO_2, 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 CO_2. 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.