Atomically thin TiO₂ nanosheets synthesized using liquid metal chemistry

Abstract

The library of two-dimensional materials is limited since many transition metal compounds are not stratified and can thus not be easily isolated as nanosheets. Liquid metal-based synthesis provides a new approach to overcome this limitation.

Liquid Metals: A Novel Possibility of Fabricating 2D Metal Oxides

“…High‐resolution imaging reveals that the TiO 2 nanosheets are of highly crystallinity. [ 86 ] These 2D TiO 2 nanosheets can be implemented as gate dielectric in modern nano‐electronics.…”

Synthesis of 2D cobalt oxide nanosheets using a room temperature liquid metal

“…This value is consistent with the ultrathin nature of nanosheets that can be produced using a similar approach from metals alloyed with galinstan reported previously that included the much more reactive metals of Gd, Hf and Al which all produced nanosheets less than 1.1 nm in thickness, 21 and Ti with nanosheets of 2 nm thickness. 42 Even though thermodynamically the oxidation of Ga is preferred, as DG f of CoO is much higher at À214.2 kJ mol À1 , the presence of 10 mM HCl results in the dissolution of any gallium oxides that are formed which subsequently promotes CoO x formation. The conditions are also appropriate for the existence of CoO x in this solution as previous work has shown that CoO only begins to dissolve to a signicant extent at concentration of 0.5 M HCl.…”

Liquid Metals‐Assisted Synthesis of Scalable 2D Nanomaterials: Prospective Sediment Inks for Screen‐Printed Energy Storage Applications

“…Recently, pure liquid metals and their alloys were used as synthesis medium or directly employed to carry out a facile and liquid‐phase free exfoliation to synthesize high‐quality and scalable 2D nanomaterials via either i) air‐injection or ii) sonication‐assisted method ( Figure ). [ 18 ] These are some innovations in synthesizing 2D nanomaterials particularly for those which have not intrinsic layered crystal structures (i.e., numerous metal oxides [ 18a,19 ] ) or those which, having strong interaction between their crystal layers (i.e., bismuth [ 18e ] ). Synthesis of these 2D nanomaterials is rather difficult using conventional approaches.…”

“…The mechanism of the chemical reaction between liquid metal surface and oxygen under reactive ambient conditions is based on the observation of the self‐limiting oxide layers formation. [ 20 ] Investigation shows that the surface of pure or liquid metal alloys such as pure gallium (Ga) [ 18a ] or gallium‐1 wt% titanium (Ga‐1 wt% Ti), [ 19 ] are composed of gallium oxide (Ga 2 O 3 ) or preferentially titanium dioxide (rutile TiO 2 ), respectively, despite the presence of a huge amount of Ga element in the case of Ga‐1 wt% Ti alloy composition. The prediction of the formed metal oxide layer in co‐alloyed metals could be done based on thermodynamic considerations such that the oxide with the largest reduction of Gibbs free energy (Δ G f ) first form on the liquid metal alloy surface.…”

“…[ 21 ] This paper aims to provide a perspective on potential applications of the exfoliated scalable 2D nanomaterials sediments in high‐performance flexible sustainable energy devices. The considered 2D nanostructures could be exfoliated either directly on a large‐scale using liquid metals (namely, 2D metal oxides, [ 18a,19 ] bismuthene [ 18e ] ) or they could be obtained by impacting the surface of the exfoliated 2D metal oxides with some other original precursors (namely, 2D GaN [ 18b ] and 2D Ga 2 S 3 [ 18d ] which could be synthesized by exposing the 2D Ga 2 O 3 with pnictogen and chalcogen elements, respectively). Thus, an overview of nanometallurgy characteristics of liquid metals and their alloys will be discussed, firstly.…”