A fracturing fluid including a base fluid including salt water, a polymer, a crosslinker, and a nanomaterial. The crosslinker may include a Zr crosslinker, a Ti crosslinker, an Al crosslinker, a borate crosslinker, or a combination thereof. The nanomaterial may include ZrO2 nanoparticles, TiO2 nanoparticles, CeO2 nanoparticles; Zr nanoparticles, Ti nanoparticles, Ce nanoparticles, metal-organic polyhedra including Zr, Ti, Ce, or a combination thereof; carbon nanotubes, carbon nanorods, nano graphene, nano graphene oxide; or any combination thereof. The viscosity and viscosity lifetime of fracturing fluids with both crosslinkers and nanomaterials are greater than the sum of the effects of crosslinkers and nanomaterials taken separately. Moreover, this synergistic effect offers significant, practical advantages, including the ability to use salt water rather than fresh water for fracturing fluids, the ability to reduce polymer loading to achieve a desired viscosity, and the ability to achieve better formation cleanup after the fracturing treatment.