Table 3 Comparison of top-down and bottom-up synthesis approaches of MXene

Precursor

Initiate from MAX phase of 3D structure

Initiate from atom to crystal growth of MXene film

[10, 36]

Method

Involves with chemical etchants such as HF acid

Apply chemical vapour deposition or salt-templating method or plasma-enhanced deposition

[36,37,38]

Synthesis condition

Pressure-less synthesis

Control gas flow as carbon source

[10, 37]

Temperature

Require room or low temperature for synthesis

Require high temperature of ~ 1000 °C for synthesis

[36]

Morphology

Large irregular MXene sheet could be produced with a lateral size of a few hundred nanometers and thin sheets with a thickness between 10 and 200 nm

Produce defect-free and highly crystalline thin film of multilayers with a lateral size of between 10 and 100 μm

[22, 36]

Surface properties

Functionalized –OH and –O after synthesis

Lack of functional groups after synthesis

[3, 37]