energy

[foolish01]

glucose is C6H12O6 right? and it burns to form Energy, H20, and CO2. but if you got the right amounts of water and carbon dioxide, with energy, to form glucose again?

[Gef]

Not sure of your question but so far no one has been able to convert carbon dioxide, water and energy to glucose in a lab.

Grren plants are pretty good at it though.

[Ray The Grey]

Theoretically it's possible, but it would require the right conditions - heat, temperature, pressure, catalysts.

As Gef says, I would recommend making something very similar to plant, as the conditions would be hard to recreate.

The H2O and CO2 bonds are much stronger than the glucose bonds (generally) and they tend to be more stable, which means the glucose molecule does not form under normal conditions

[Gnisy]

Sounds like a job for photosynthesis!
With plants around, there isn't much need for glucose to be synthesized in the laboratory. Of course in the likely event that deforestation clears off most of the forests in the world, that would ultimately be of the highest priority in science.