The development of scalable and reliable three-dimensional macroscopic functional aerogels is of remarkable significance because of their wide applications in the energy and environmental fields. Although the metal–organic frameworks (MOFs) have shown promising applications in water remediation, the construction of MOFs-based aerogels is highly challenging. Herein, for the first time, we report a general strategy for one-step fabrication of a ZIF-8 MOF/reduced graphene-oxide hydrogel in a short period via self-assembly, with the synergistic effects of chemical reduction and cross-linking by metal ions; upon drying, the hydrogel yields the ZIF-8/reduced graphene-oxide aerogel. The highly porous ZIF-8 hybrid aerogel displays high absorption capacity and cycling stability for oils and organic solvents, due to its superhydrophobic properties and high specific surface areas. In addition, the corresponding hydrogel demonstrates photocatalytic dye degradation ability, as well as excellent water purification performance for removing toxic dyes, heavy metal ions and benzo pollutants. Our synthetic strategy is proven to be versatile for constructing a variety of functional nanocomposite hydro-/aerogels towards customized water remediation.