can't you split it into oxygen and carbon? then just dump the carbon? that way you have a supply of oxygen and over time couldn't you grow plants? can you then

can't you split it into oxygen and carbon? then just dump the carbon? that way you have a supply of oxygen and over time couldn't you grow plants? can you then also get the hydrogen out of sulfuric acid and combine the hydrogen and oxygen to make water? use some of the hydrogen to run a nuclear fusion reactor? and if you did this on large scale and time span wouldn't the pressure start to lower? or is that just no possible?