Measurement Conditions and Uncertainty Evaluation of Specific Surface Area of Graphene Powder by Nitrogen Adsorption Method

Specific surface area of redox graphene/metal oxide powder was measured by ASAP 2460 specific surface area and porosity analyzer using nitrogen adsorption static capacity method (nitrogen adsorption method). The ideal test conditions were determined, and the measurement uncertainty was evaluated. The results show that the ideal sample amount for measuring the specific surface area of graphene powder by nitrogen adsorption method is 0.2~0.4 g. The uncertainty evaluation of specific surface area only considers the standard uncertainty introduced by measurement repeatability, the weight of sample weighed by the balance and the standard sample. When the confidence level p is 95% and the degree of freedom V_rel is 32, the expanded uncertainty of specific surface area of graphite sample measured by nitrogen adsorption method physical adsorption instrument is 14.55 m²·g^-1.