water has the higher boiling point.
both water and Co2 contain Van der waals holding its molecules together but as water is polar as it contains a dipole it can create Hydrogen bonds between its atoms delta+ hydrogen and its delta- oxygen from another molecule. Hydrogen bonds are the strongest intermolecular forces.
if ever worried about this think of the elements state at room temp. Co2 is a gas where as water is a liquid so we can speculate that water has the highest Bp
hope that helps.