Effect of Pretreatment Conditions on the Precise Nanoporosity of Graphene Oxide

Nanoscale pores in graphene oxide (GO) control various important functions. The nanoporosity of GO is sensitive to low-temperature heating. Therefore, it is important to carefully process GO and GO-based materials to achieve superior functions. Optimum pretreatment conditions, such as the pre-evacuation temperature and time, are important during gas adsorption in GO to obtain accurate pore structure information. This study demonstrated that the pre-evacuation temperature and time for gas adsorption in GO must be approximately 333-353 K and 4 h, respectively, to avoid the irreversible alteration of nanoporosity. In situ temperature-dependent Fourier-transform infrared spectra and thermogravimetric analysis-mass spectrometry suggested significant structural changes in GO above the pre-evacuation temperature (353 K) through the desorption of physically adsorbed water and decomposition of unstable surface functional groups. The nanoporosity of GO significantly changed above the aforementioned pre-evacuation temperature and time. Thus, standard pretreatment is indispensable for understanding the intrinsic interface properties of GO.

Automated summary

The nanoporosity of graphene oxide (GO) is sensitive to low-temperature heating, emphasizing the importance of carefully processing GO and GO-based materials for superior functions. Optimum pretreatment conditions, such as pre-evacuation temperature and time, are crucial for accurate pore structure information during gas adsorption in GO. Results suggest that specific pre-evacuation temperature and time (approximately 333-353 K and 4 h, respectively) are necessary to avoid irreversible changes in nanoporosity. Additionally, significant structural changes were observed in GO above the pre-evacuation temperature, indicating the importance of standard pretreatment for understanding intrinsic interface properties of GO.