May not be an economic option, but may be just a good option for zero-carbon emission. Still have a long way to go for the safe storage and transportation. Also, not limited to store hydrogen by combining with carbon, but combining with nitrogen is another very good choice to form ammonia.

I don't see it being a mainstream fuel any time soon.  But there may be uses for it.  There are two common ways to make hydrogen:-

• Extract it from fossil fuels, usually natural gas.  But the byproducts of this includes carbon dioxide.  This makes it pretty pointless as an eco-friendly fuel.  You might as well just burn the methane.
• Extract it from water by electrolysis.  This requires lots of electricity, and the energy embodied in the hydrogen you produce is rather less than in the electricity you used to extract it.  This does still make sense of we go all-out for wind and solar electricity, as we will most likely have unwanted excess electricity whenever it's very sunny or windy.

Carbon dioxide does dissolve in water, but not easily.  It forms carbonic acid.  If you make too much of that, you risk killing off all the shellfish in the area.  They rely on seawater being slightly alkaline, in order that they can grow their shells.

There are a few ways to store hydrogen, other than by stuffing it into tanks. https://www.energy.gov/eere/fuelcells/hydrogen-storage