Chapter 4
Synthesis of Two-Dimensional (2D)
Nanomaterials
Recently, the development of graphene nanosheets has ushered 2D nanomaterials into
the limelight for energy storage and conversion devices. These graphene-like nanostructures, including transition metal hydroxides (TMHs), transition metal oxides
(TMOs), transition metal dichalcogenides (TMDs), MXene, etc., feature atomic-level
thickness, large surface area, tunable electronic properties, remarkable mechanical
strength, and unique confined effect. Until now, variety of synthetic methods, novel
designs of electrode, and microstructure tuning of these 2D materials have been
discussed to achieve high power and energy densities (Zhang 2015; Xu et al. 2013;
Tan et al. 2017; Koski and Cui 2013; Mei et al. 2017; Wu et al. 2014; Dong et al.
2017).
4.1 2D Transition Metal Dichalcogenides
4.1.1 MoS 2
2D TMDs refer to a kind of novel materials with layered structure, the unit cell of
which is comprised of a transition metal (M = Mo or W) layer sandwiched between
two chalcogen (X = S, Se, or Te) layers in the form of MX 2 (Cao et al. 2013; Muller
et al. 2015). Molybdenum disulfide (MoS 2 ), 2D layers which stacked one over other
by van der Waals interaction, has desirable properties similar to graphene (Chen et al.
2013; Ting et al. 2016; Moses et al. 2009; ArunKumar et al. 2017). Exfoliation of the
TMDs into single or multiple layer sheets was discovered to enhance the chemical
properties of TMDs due to the increase of available surface area and tuning of their
electronic properties. This allows for potential applications in capacitors, batteries,
vapor sensing, and biosensing applications (Pumera et al. 2014; Chia et al. 2015; Su
et al. 2016). However, the electrochemical performance of few-layer or monolayer
MoS 2 nanosheets is still impeded by their inherent limitations (Wang et al. 2014; Jiang
and Zeng 2015). Despite the large capacity, the exfoliated MoS 2 nanosheets often
© Springer Nature Singapore Pte Ltd. 2020
H. Pang et al., Synthesis of Functional Nanomaterials for Electrochemical Energy Storage,
https://doi.org/10.1007/978-981-13-7372-5_4
55
Synthesis of Two-Dimensional (2D)
Nanomaterials
Recently, the development of graphene nanosheets has ushered 2D nanomaterials into
the limelight for energy storage and conversion devices. These graphene-like nanostructures, including transition metal hydroxides (TMHs), transition metal oxides
(TMOs), transition metal dichalcogenides (TMDs), MXene, etc., feature atomic-level
thickness, large surface area, tunable electronic properties, remarkable mechanical
strength, and unique confined effect. Until now, variety of synthetic methods, novel
designs of electrode, and microstructure tuning of these 2D materials have been
discussed to achieve high power and energy densities (Zhang 2015; Xu et al. 2013;
Tan et al. 2017; Koski and Cui 2013; Mei et al. 2017; Wu et al. 2014; Dong et al.
2017).
4.1 2D Transition Metal Dichalcogenides
4.1.1 MoS 2
2D TMDs refer to a kind of novel materials with layered structure, the unit cell of
which is comprised of a transition metal (M = Mo or W) layer sandwiched between
two chalcogen (X = S, Se, or Te) layers in the form of MX 2 (Cao et al. 2013; Muller
et al. 2015). Molybdenum disulfide (MoS 2 ), 2D layers which stacked one over other
by van der Waals interaction, has desirable properties similar to graphene (Chen et al.
2013; Ting et al. 2016; Moses et al. 2009; ArunKumar et al. 2017). Exfoliation of the
TMDs into single or multiple layer sheets was discovered to enhance the chemical
properties of TMDs due to the increase of available surface area and tuning of their
electronic properties. This allows for potential applications in capacitors, batteries,
vapor sensing, and biosensing applications (Pumera et al. 2014; Chia et al. 2015; Su
et al. 2016). However, the electrochemical performance of few-layer or monolayer
MoS 2 nanosheets is still impeded by their inherent limitations (Wang et al. 2014; Jiang
and Zeng 2015). Despite the large capacity, the exfoliated MoS 2 nanosheets often
© Springer Nature Singapore Pte Ltd. 2020
H. Pang et al., Synthesis of Functional Nanomaterials for Electrochemical Energy Storage,
https://doi.org/10.1007/978-981-13-7372-5_4
55