Similar to graphene, WO3 can be mechanically or chemically exfoliated to provide fundamental layers. However, unlike Hormones inhibitor graphene, which does not have bandgap, Q2D WO3 has rather large bandgap, making Q2D WO3 nanoflakes more versatile as candidates for thin, flexible devices and potential applications in catalysis [6], optical switches [7] displays and smart windows [8], solar cells [9] optical recording devices [10] and various gas sensors [11]. It has become one of the most investigated functional semiconductor

metal oxides impacting many research fields ranging from condensed-matter physics to learn more solid-state chemistry [10]. However, despite great interest of the research and industrial communities to the bulk and microstructured WO3, nanoscaled Q2D WO3 with thickness less than ~10 nm has received relatively little attention so far compared LY3023414 molecular weight to its microstructured counterparts and to Q2D transitional metal dichalcogenides MX2 (M = Mo, W; X = S, Se, Te). In addition, last year’s reports on alternative transitional semiconductor oxide Q2D MoO3 have exhibited exceptional thickness-dependent

properties and the substantial increased of the charge carriers mobility (up to 1,100 cm2 V-1 s-1) in Q2D MoO3 [2, 12]. It was also recently proven for MoSe2 that the reduction of bandgap can be achieved through decreasing the thickness of Q2D nanoflakes down to monolayer [13]. Therefore, realization of WO3 in its Q2D form can further engineer the materials’

electrical properties, as quantum confinement effects in 2D form will significantly influence charge transport, electronic band structure and electrochemical properties [3]. More importantly, nanostructuring of WO3 can enhance the performance of this functional Q2D material revealing unique properties that do not exist in its bulk form [2]. The development of Q2D materials is generally a two-step process, the synthesis of the layered bulk material followed by the exfoliation process [14]. Although there is a wide range of controlled methods of synthesis available to produce different morphologies of WO3 nanostructures, such as microwave-assisted hydrothermal [15], vapour-phase deposition [16], sol-gel [17], electron-beam [18] and arc-discharge [19], synthesis of Q2D MG-132 concentration WO3 is a topic that is yet to be widely explored. For instance, in a recent report, it was demonstrated that one possible way of bandgap reduction in bulk WO3 is to increase its sintering temperature [20]. However, what is the most favourable sintering temperature for exfoliation Q2D WO3 nanoflakes remains largely unexplored. In this work, we present for the first time new distinguishing thickness-dependent electrical properties of Q2D β-WO3 obtained for nanoflakes with thickness below ~10 nm developed via two-step sol-gel-exfoliation method. These properties were mapped without damaging the sample by carefully controlling the sample-tip force.