The under-oil water droplet can keep quasi-spherical shape on the surface of C-1000 with 146 of water contact angle. The particular wettability achieved in oil/water/solid three-phase system may be mainly attributed to the multiscale surface structure of the carbon monolith, in which those trapped oil molecules can greatly reduce the contact area between water and carbon monolith surface, leading to a large water contact angle under oil [24].