@codepuppy CO2 is absurdly stable, which is why it's a combustion product and why Venus is full of it.
Each C=O bond in a CO2 molecule has a bond enthalpy of 804.4 kJ/mol. That works out to 8.342 eV so photodissociation would need a photon with λ > 148.63 nm. That's scary far UV.
A krypton excimer laser (146 nm) could break it, but a good catalyst would be far more efficient. :)
Science teacher. My mom thinks I'm cool.