Electrostatic-Driven Exfoliation and Hybridization of 2D Nanomaterials

Abstract

Here, direct and effective electrostatic-driven exfoliation of tungsten trioxide (WO₃ ) powder into atomically thin WO₃ nanosheets is demonstrated for the first time. Experimental evidence together with theoretical simulations clearly reveal that the strong binding of bovine serum albumin (BSA) on the surface of WO₃ via the protonation of NH₂ groups in acidic conditions leads to the effective exfoliation of WO₃ nanosheets under sonication. The exfoliated WO₃ nanosheets have a greatly improved dispersity and stability due to surface-protective function of BSA, and exhibit a better performance and unique advantages in applications such as visible-light-driven photocatalysis, high-capacity adsorption, and fast electrochromics. Further, simultaneous exfoliation and hybridization of WO₃ and MoS₂ nanosheets are demonstrated to form hybrid WO₃ /MoS₂ nanosheets through respective electrostatic and hydrophobic interaction processes. In addition, this electrostatic-driven exfoliation strategy is applied to exfoliate ultrathin black-phosphorus nanosheets from its bulk to exhibit a greatly improved stability due to the surface protection by BSA. Overall, the work presented not only presents a facile and effective route to fabricate 2D materials but also brings more opportunities to exploit unusual exotic and synergistic properties in resulting hybrid 2D materials for novel applications.

Keywords: black phosphorus; electrostatic; hybridization; nanosheets; tungsten trioxide.