Electrostatic‐Driven Exfoliation and Hybridization of 2D Nanomaterials

Abstract

Here, direct and effective electrostatic-driven exfoliation of tungsten trioxide (WO ) powder into atomically thin WO 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 WO via the protonation of NH groups in acidic conditions leads to the effective exfoliation of WO nanosheets under sonication. The exfoliated WO 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 WO and MoS nanosheets are demonstrated to form hybrid WO /MoS 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.

Functionalized Hybridization of 2D Nanomaterials

“…[258] Similarly, Zhang's group prepared MoS 2 -MoO 3 hybrids via a heat-assisted partial oxidation of chemically exfoliated MoS 2 sheets in air and subsequent thermal annealing-driven crystallization. [42] Experimentally, the simultaneous exfoliation of WO 3 and MoS 2 nanosheets under the assistance of BSA led to the effective hybridization of WO 3 and MoS 2 nanosheets (Figure 20b), which extended photoresponsivity of 2D nanomaterials to a wider spectral range from near-infrared, visible to ultraviolet region. In Bessonov's work, a novel memristive device was fabricated by sandwiching a MoO x /MoS 2 or WO x /WS 2 (x < 3) heterostructure between two printed silver electrodes, exhibiting an unprecedentedly large and controlled electrical resistance range from 10 2 to 10 8 Ω as well as low programming voltages at 0.1-0.2 V. [260] In our recent work, a facile BSA-mediated strategy was developed to successfully exfoliated WO 3 and MoS 2 nanosheets in BSA solution and further hybridize them to sandwiched WO 3 -BSA-MoS 2 nanostructures via electrostatic and hydrophobic interactions, respectively (Figure 20a).…”

“…For example, graphite is first oxidized into graphene oxide (GO) in bulk as an intermediate followed by sonication-driven exfoliation into GO nanosheets and further reduction to reduced GO (RGO) nanosheets for restoring sp 2 -conjugated network and electrical conductivity, [41] resulting in gram-level production superior to other methods by directly using graphite. [42] In contrast, various nanosheets can be also synthesized via chemical reactions of special precursors under certain experimental conditions (i.e., the so-called bottom-up technique). [42] In contrast, various nanosheets can be also synthesized via chemical reactions of special precursors under certain experimental conditions (i.e., the so-called bottom-up technique).…”

“…In Ma's work, the epitaxial growth of Au nanocrystals on MoO 3 nanosheets was realized under ultraviolet irradiation by using MoO 3 nanosheets as both electron carriers and sacrificial templates, which were used as homogeneous SERS substrates for constructing a detection platform toward malachite green pigment. [42] The capping of BSA on surface of WO 3 nanosheets suggested a chemical dissolution process to create hole on WO 3 sheets. [214] Recently, the growth of α-Fe 2 O 3 nanorods on surface of α-MoO 3 nanobelts was also realized by a hydrothermal approach for developing xylene gas sensor with high response and low operating temperature.…”

“…Typically, the hybridization of BN layers on BP sheets not only solved the instability of BP sheets, [42] Copyright 2017, Wiley-VCH. Typically, the hybridization of BN layers on BP sheets not only solved the instability of BP sheets, [42] Copyright 2017, Wiley-VCH.…”

Tris‐Stabilized MoS2 Nanosheets with Robust Dispersibility and Facile Surface Functionalization

“…Meanwhile, graphene has also the excellent characteristics in electron mobility and intrinsic strength . However, the lack of an electronic bandgap limits the applications of graphene in photoresponsive areas such as photoelectronics, photocatalysis, and photo‐to‐energy conversion . An important alternative, transition‐metal dichalcogenide (TMD) nanosheets in single and few layers, have a layer‐dependent bandgap in the range from 0.8 to 2.4 eV (the thinner layer corresponds with the larger bandgap), which provide a wide photo absorption window from the infrared to visible regime .…”