This process doesn't capture carbon, it captures CO2. Splitting CO2 back to Carbon and Oxygen does indeed take a great deal of energy, but if you can efficient

This process doesn't capture carbon, it captures CO2. Splitting CO2 back to Carbon and Oxygen does indeed take a great deal of energy, but if you can efficiently and cheaply store CO2 permanently (underground, in concrete, in greenhouse-grown plants, or wherever) then this can still be a net win.