An apparatus for capturing carbon dioxide has a membrane separator with a gas inlet, a gas outlet, a channel that extends between the gas inlet and the gas outlet, and pores configured to permit carbon dioxide to pass therethrough, the gas inlet being connected to receive a mixed gas that contains carbon dioxide, wherein carbon dioxide in the mixed gas exits the membrane via the pores, and a remainder of the mixed gas exits the membrane separator via the gas outlet. The pores may be functionalized with nano-particles. A container is filled with an aqueous solution includes a carbon capturing agent and the membrane separator is submerged within the aqueous solution. The carbon capturing agent may be produced by a membrane reactor upstream of the membrane separator. Carbon dioxide exiting the membrane separator via the functional pores reacts with the carbon capturing agent to produce a carbon negative compound.