Superhydrophilic Nickel Nanoparticles with Core–Shell Structure To Decorate Copper Mesh for Efficient Oil/Water Separation

Abstract

Recently, oil/water separation has attracted intensive attention due to the frequent crude oil spill accidents and the increasing amount of industrial wastewater. Thousands of outstanding achievements have been reported on the basis of membranes with superhydrophilicity and underwater superoleophobicity. However, a universal approach combining cheaper reagents with easier operations to fabricate superhydrophilic materials for effective oil/water separation is still a challenge and greatly encouraged. In the present work, we fabricate the superhydrophilic copper mesh decorated with nickel nanoparticles (Ni-NPs) via electrodeposition in fluorine-containing electrolyte. The size of Ni-NPs that consists of a metal Ni core and a polar NiO/Ni(OH) 2 shell is about 300 nm; what's more, the Ni-NPs combine with each other to form treelike nickel crystals by varying the experimental parameters. This optimized mesh exhibits remarkable oil/water separation performance. The oil content in separated water is lower than 3 ppm, and the stability in acidic, alkaline, and salt solutions and the properties for repeated use are also excellent. Further, we provide a novel approach to synthesis superhydrophilic nanoparticles with a core−shell structure for coating or other applications such as catalysis, self-cleaning, antifogging, and so on.

A glucose modified filter paper for effective oil/water separation

“…The oil contents remained in ltrates were also measured, and they are less than 10 mg L À1 (Table S2 †), which is comparable to that of the copper mesh decorated with superhydrophilic nickel nanoparticles. 38 Those results indicate the excellent performance of the glucose modied lter papers in oil/ water mixture separation. Interesting, the ux increases obviously when glucose concentration is larger than 4%, and the saturatedglucose-solution modied lter paper has a water ux as high as 4424 AE 60 L m À2 h À1 .…”

“…22,23 By utilization of macromolecular layers, nano or micro-particles, nano bres, and etc., a large number of superhydrophilic and underwater superoleophobic materials have been described and drawn extensive attentions due to their highly efficient ltrations and broad application prospects on oil/water separation. 17,[24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] Filter paper, with its porous structure constructed by cotton microbers, is widely used in solid-liquid separation. Natural cotton bres consist of numerous brils of b-glucose with cuticle covered by 55% cellulose and the other non-cellulosic compounds like pectin, protein, and wax, 39 which makes primary lter paper impractical for liquid-liquid separation.…”

Super-stable non-woven fabric-based membrane as a high-efficiency oil/water separator in full pH range

“…21 The separation principle is that the oil phase spreads and penetrates through the membrane easily, while simultaneously, the water phase is hindered. [22][23][24][25][26][27] Most of these membrane materials are synthesized by modifying different materials on various porous metal substrates, such as copper grid, nickel grid and stainless steel. 8,14,22,24 As a result, the abovementioned membranes are generally applied in a neutral environment for oil/water separation, and it is difficult to realize the separation operation in another harsh environment, such as strong acid or strong alkali oily wastewater.…”

A smart engineering material with UV‐induced switchable wettability for controllable oil/water separation

“…Nevertheless, 'oil-removing' types of materials are easily fouled with oil of high viscosity. In recent years, inspired by fish skin's antifouling capacity in oil-polluted water, a number of superhydrophilic/underwater superoleophobic materials [15][16][17][18][19][20][21][22] have been developed for oil/water separation or 'water-removing', which allows water permeation but blocks oil penetration. Unfortunately, these separating materials mentioned above have some limitations in special applications such as remote operation and on-demand automation of the oil/water separation process due to the lack of good flexibility and controllability.…”