Could UV lasers be used to split CO2 and H2O?

In summary: The photolysis of water and carbon dioxide is not as easy as it seems. There are several disadvantages to using UV light as a way to split the molecules. First, it is difficult to find an efficient UV light source. Second, the light must be intense enough to break the bonds between the molecules. Third, the molecules must be dense enough for the light to break the bonds. Fourth, the reactions must be efficient. Fifth, the byproducts of the reaction must be benign.
  • #1
jcap
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I was wondering whether intense UV light, tuned to the correct wavelength, could be used to split carbon dioxide and water molecules as a first step towards synthesizing liquid fuels.
 
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  • #2
To what end?
 
  • #3
Bystander said:
To what end?
Well, to make hydrocarbon fuels efficiently using solar electricity rather than getting them out of the ground and adding to global warming.
 
  • #4
I really don't know what the question is trying to say. Are you asking would a photochemical reaction of water and carbon dioxide lead to hydrocarbon fuels?
 
  • #6
HAYAO said:
I really don't know what the question is trying to say. Are you asking would a photochemical reaction of water and carbon dioxide lead to hydrocarbon fuels?
I'm asking whether uv light can be used to efficiently spit H20 and CO2 molecules. I understand that UV photons have roughly the same energy as covalent bonds so I thought it might be possible.
 
  • #7
Just breaking a bond is only a smart part of the process, not necessarily the most important one. Even assuming you were able to split water into oxygen and hydrogen you get a mixture of two highly reactive gases being heated and excited by the UV radiation. Guess what will happen next.
 
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  • #8
Borek said:
Even assuming you were able to split water into oxygen and hydrogen you get a mixture of two highly reactive gases being heated and excited by the UV radiation. Guess what will happen next.

The OP is talking about the photolysis of water and carbon dioxide (and not just pure water). It is not as easy to guess what happens with a mixture of H2O, H2, O2, H, O, OH, CO2, CO and C. That would strongly depend on the conditions and the presence of catalysts.
 
  • #9
jcap said:
I'm asking whether uv light can be used to efficiently spit H20 and CO2 molecules. I understand that UV photons have roughly the same energy as covalent bonds so I thought it might be possible.
Okay, then the answer is very unlikely.

Might want to rely on photocatalysts instead. There are several difficulties in using UV lights source including, but not limited to, 1) do we have a efficient UV light source? 2) How "intense" is the light source? 3) How dense are the H2O and CO2 molecules? 4) How efficient are the reactions itself? 5) How about the byproducts?
Given these question, would using UV light source overcome the disadvantages?
 

Related to Could UV lasers be used to split CO2 and H2O?

1. Can UV lasers effectively split CO2 and H2O?

Yes, UV lasers have been shown to be effective in splitting molecules such as CO2 and H2O through a process called photolysis. This is because UV light has enough energy to break the bonds between the atoms in these molecules, resulting in the formation of smaller molecules.

2. How does the process of photolysis work?

Photolysis is a photochemical reaction in which a molecule absorbs a photon of light, typically in the UV range, and breaks apart into smaller molecules. In the case of CO2 and H2O, the UV laser provides the necessary energy to break the bonds between the carbon and oxygen atoms in CO2 and the hydrogen and oxygen atoms in H2O, resulting in the formation of carbon monoxide (CO) and hydrogen (H2).

3. What are the potential applications of using UV lasers to split CO2 and H2O?

The splitting of CO2 and H2O using UV lasers has potential applications in the fields of renewable energy and sustainable fuel production. The resulting CO and H2 can be used as building blocks for synthesizing various fuels, such as methanol and methane, which can then be used as alternatives to fossil fuels.

4. Are there any limitations to using UV lasers for splitting CO2 and H2O?

One limitation is the high cost of UV lasers and the energy required to power them. Additionally, the process of photolysis may not be as efficient as other methods of splitting molecules. Further research is needed to optimize the process and make it more cost-effective.

5. Is the use of UV lasers to split CO2 and H2O environmentally friendly?

As with any technology, the environmental impact depends on the source of energy used to power the UV lasers. If renewable energy sources are used, such as solar or wind power, then the process can be considered environmentally friendly. However, the production and disposal of the UV lasers themselves may have some environmental consequences. More research is needed to fully assess the environmental impact of this technology.

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