Cupric Phosphate Nanosheets-Wrapped Inorganic Membranes with Superhydrophilic and Outstanding Anticrude Oil-Fouling Property for Oil/Water Separation

Developing an effective and sustainable solution for cleaning up or separating oily water is highly desired. In this work, we report a completely inorganic mesh membrane made up of cupric phosphate (Cu-3(PO4)(2)) in a special intersected nanosheets-constructed structure. Combing the hierarchical structure with strong hydration ability of Cu-3(PO4)(2), the nanosheets-wrapped membrane exhibits a superior superhydrophilic and underwater anti oil fouling and antibio-fouling property for efficient oil/water separation to various viscous oils such as heavy diesel oil, light crude oil, and even heavy crude oil with underwater oil contact angles (CAs) all above 158 degrees and nearly zero underwater oil adhesive force even when a large preload force of up to 400 mu N was applied on the oil droplet. Simultaneously, the membrane exhibits a high chemical and thermal stability and outstanding salt tolerance. Continuous separation operated on a cross-flow filtration apparatus demonstrates a large separation capacity and long-term stability-of the membrane during treating a 2000 L crude oil/water mixture with constantly stable permeating flux of similar to 4000 L/m(2) h and oil content in the filtrate below 2 ppm. The excellent anti-oil fouling property, high separation capacity, and easily scaled-up preparation process of the membrane show great potential for practical application in treating oily wastewater.