Reduced graphene oxide-coated cottons for selective absorption of organic solvents and oils from water

Abstract

Superwetting materials have attracted considerable interest both in academia and industry. In this work, the reduced graphene oxide (RGO)-coated cotton (GCC) was prepared by a facile and inexpensive dip-coating method. By modification with polydimethylsiloxane (PDMS), superhydrophobic and superoleophilic GCC was obtained, which shows a water contact angle of 152 . The PDMS-treated GCC exhibits selective absorption of organics and oils from water with an absorption capacity up to 11 to 25 times its weight. Also, the as-prepared product shows excellent stability and recyclability; both saturated absorption capacity and water CA value remain nearly unchanged after 9 cycles of use. Taking advantage of the excellent absorption selectivity, simple fabrication process, good stability and recyclability, this material may find a variety of applications such as in water treatment, purification, separation, oil spill cleanups and so on.

Reduced graphene oxide-coated cotton as an efficient absorbent in oil-water separation

“…Over the last few years, carbonaceous materials such as carbon nanotubes [18], carbon black [19], expanded graphite [10,20], graphene aerogels [21,22], reduced graphene oxide (rGO) [23], and carbon nanofibers [24] have emerged as materials of choice for oil spill clean-up owing to their excellent non-wettability towards water. Among all, graphene-based sorbents have attracted significant attention for oil-water separation due to their ease of fabrication, superhydrophobicity, and high surface area, along with excellent chemical, thermal, and mechanical stability [25,26].…”

“…On the contrary, rGO shows hydrophobic behavior due to the absence of any functional groups [29,30]. Recently, rGO/cotton fabric [23], rGO/ membrane [31], and rGO/polyurethane-based sponges [32] have shown promise as sorbents for oil-water separation. Gupta and Tai [9] recently reviewed various carbonaceousbased compounds as oil absorption materials which highlight that rGO or graphene has superior oil absorption capacities.…”

“…Gupta and Tai [9] recently reviewed various carbonaceousbased compounds as oil absorption materials which highlight that rGO or graphene has superior oil absorption capacities. Sun et al [23] demonstrated rGO-coated cotton functionalized by polydimethoxysilane could remove oils~11-25 times of its weight. Ge et al [33] reported~30-50 times absorption capacities for various oils using rGO-coated cotton.…”

Thermal reduction of graphene-oxide-coated cotton for oil and organic solvent removal

“…The use of graphene/RGO sponges and aerogels for oil and solvent removal is very attractive and effective; however, the preparations of these materials are expensive, difficult to scale up, and result in brittle materials. The use of commercial sponges coated with graphene/ RGO has attracted attention because of their low cost, flexibility, and recyclability [29,[38][39][40][41][42]. Most of these methods use a facile dipping method for the preparation of graphene/RGO-coated commercial sponges.…”

“…To use commercial cotton as selective sorbent, it should be hydrophobically modified [43][44][45][46][47][48]. In very recent years, the fabrication of graphene/RGO-coated cotton has been investigated [40,41]. This material showed fairly good selective absorption capacities for various types of oils and organic solvents.…”