# Research Progress and Applications of 2D Antimonene
## 2 Theoretical Research and Experimental Methods
### Liquid Phase Exfoliation
When the hydrothermal reaction is carried out at atmospheric pressure, antimonene cannot be spalled off. However, when the pressure is too high, only antimonene fragments can be obtained. Large-sized antimonene can be obtained only when 14 mL n-butyllithium is placed in a 50 mL of autoclave at 80 \({}^{\circ}\)C, as shown in Figure 6.  
In order to study the experimental conditions of antimonene film thickness, antimonene films with adjustable thickness were prepared. By changing the centrifugal speed from 1000 rpm to 9000 rpm, [PERSON] et al. [47] prepared antimonene with a thickness of 0.5-7 nm. The antimonene crystals were ground in 2-butanol and ultrasonic cleaning was carried out in 2-butanol solvent with tip ultrasonic device. The thickness of antimonene was approximately 5-7 nm at the low centrifugal speed range of 1000-2000 rpm. When the centrifugal speed is 2000-5000 rpm, the thickness of antimonene is approximately 2-3 nm. When the centrifugal speed is increased to 5000-9000 rpm, the thickness of antimonene is reduced to approximately 0.5-1.5 nm. When the centrifugal speed is increased to  
Figure 5: (**a**) The concentration of antimonene in the suspension after centrifugation [Sb] (g-L\({}^{-1}\)), plotted with the precipitation time of the sample prepared with the solvent described in the legend; (**b**) the relationship between the DA ratio of antimonene nanolayer and the volume fraction (%) of water in the solvent mixture. Reprinted with permission from Ref. [44]. Copyright 2019, Royal Society of Chemistry. Figure 6: Schematic diagram of liquid phase separation for pressure alloying. Reprinted with permission from Ref. [46]. Copyright 2021, John Wiley and Sons. 9000 rpm, homogeneous antimonene quantum dots with a size of 20-30 nm and a thickness of 0.3-1 nm are formed. Besides the influence of centrifugation, grinding and solvent, the ultrasonic power and ultrasonic cleaning time also affect the preparation of antimonene. For example, [PERSON] et al. [48] prepared antimonene nanosheets with a thickness of 0.6 nm and transverse size of 0.55 \(\pm\) 0.36 \(\upmu\)m by extending ultrasonic cleaning time. [PERSON] et al. [49] prepared antimonene with a thickness of approximately 0.5 nm and a transverse size of approximately 700 nm through high Hypersonic waves and high power. Grinding antimonene, centrifugal speed, ultrasonic and solvent all have influences on the preparation of antimonene. Wet ball grinding, high centrifugal speed, high power ultrasonic for a long time and surface energy matching solvent are more conducive to the preparation of antimonene with lower thickness. Grinding the antimony powder first is beneficial to the exfoliation of antimony. The grinding of antimony powder provides shear force on the surface of Sb layer. Compared with mechanical exfoliation method, the grinding of antimony powder provides shear force on the surface of Sb layer in a more controllable way, promotes the transverse spalling, thus producing a larger and thinner antimony film, and avoids the longitudinal destruction of antimony film atoms. Ultrasound and centrifugation also have great influence on the preparation of antimonene. Since ultrasound can provide energy to break the van der Waals interaction between the antimony atomic layers, together with grinding, they are beneficial to produce thin antimony film. Grinding with high power ultrasonic wave or prolonged ultrasonic time are aimed at exfoliation with higher concentration and thinner antimonene. However, different centrifugal speeds can produce antimonene with different thicknesses. For example, [PERSON] et al. [47] prepared antimonene thin films with thickness of 0.5-7 nm at different centrifugal speeds. Antimonene can be exfoliated in a variety of solvents. When the surface energy of the solvent matches the surface energy of the stripped layered crystal, the energy cost is lowest and the concentration of the suspension is maximized.