Khalili Drermani Ensiyeh, Afzalzadeh Reza
Faculty of Physics, K. N. Toosi University of Technology, Tehran, 15418-49611, Iran.
Sci Rep. 2024 Sep 30;14(1):22682. doi: 10.1038/s41598-024-72120-9.
In the present research, comparative simulation and experimental investigation were carried out for two different probes to improve the efficiency and quality of few-layer graphene utilizing liquid-phase exfoliation. Two differently designed shaped probes are fabricated for this study, i.e., a simple probe and a stepped probe. The acoustic pressure distribution in the vessel is simulated for both probes at different output powers. In the experiment, both probes exfoliate graphite powder in a mixture of deionized water and ethanol. Different sonication times and output power were studied for different pulse modes. The graphene layers were characterized using Ultraviolet-visible spectroscopy (UV‒Vis), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Raman Microscope. The simulation shows that the total displacement on the tip of the stepped probe is 5.7% greater than that of the simple probe. Also, the pressure difference produced by the stepped probe is 9.15 × 10 pa compared to the pressure difference of the simple probe which is 8.23 × 10 pa. Consequently, the stepped probe was more effective in exfoliating graphene. The experimental results show that the absorbance peak in the stepped probe is approximately 32% greater than the absorbance peak in the simple probe with the same output power. Also, the graphene with better quality is produced with the stepped probe compared to the simple probe, which verifies the simulation findings. Additionally, the optimum output power, pulse duration, and sonication time to produce graphene with less time and energy consumption are obtained. The best graphene flakes were obtained via sonication with a pulse duration of 0.7 s, an output power of 282 W, and a sonication time of 45 min using a stepped probe. UV-Vis., SEM and TEM analysis show increases in quantity and quality of the exfoliated flakes. These results are approved by the peak ratio of I/I around 1 in Raman spectra revealed the production of the few-layer graphene by the simple probe and the bilayer graphene by the stepped probe. So, this method is suitable for the production of graphene flakes from graphite in suitable quantity and quality.
在本研究中，对两种不同的探头进行了对比模拟和实验研究，以提高利用液相剥离法制备少层石墨烯的效率和质量。为此研究制作了两种不同设计形状的探头，即简单探头和阶梯式探头。针对两种探头在不同输出功率下模拟了容器内的声压分布。在实验中，两种探头均在去离子水和乙醇的混合液中剥离石墨粉。针对不同的脉冲模式研究了不同的超声处理时间和输出功率。使用紫外可见光谱（UV-Vis）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和拉曼显微镜对石墨烯层进行了表征。模拟结果表明，阶梯式探头尖端的总位移比简单探头大5.7%。此外，阶梯式探头产生的压差为9.15×10帕，而简单探头的压差为8.23×10帕。因此，阶梯式探头在剥离石墨烯方面更有效。实验结果表明，在相同输出功率下，阶梯式探头的吸光度峰值比简单探头大约32%。此外，与简单探头相比，阶梯式探头制备的石墨烯质量更好，这验证了模拟结果。此外，还获得了以更少的时间和能量消耗制备石墨烯的最佳输出功率、脉冲持续时间和超声处理时间。使用阶梯式探头，在脉冲持续时间为0.7秒、输出功率为282瓦、超声处理时间为45分钟的条件下，通过超声处理获得了最佳的石墨烯薄片。紫外可见光谱、扫描电子显微镜和透射电子显微镜分析表明，剥离薄片的数量和质量有所增加。拉曼光谱中I/I的峰值比约为1，证实了简单探头制备出了少层石墨烯，阶梯式探头制备出了双层石墨烯，从而验证了这些结果。所以，该方法适用于以合适的数量和质量从石墨制备石墨烯薄片。
