Determination of Iron Content in Carbon Nanotubes Using the Oxygen-Flask Combustion Pretreatment Method

Abstract

To facilitate the rapid and straightforward determination of iron content in carbon nanotubes (CNTs), we employed the oxygen-flask combustion pretreatment method. During combustion, barely soluble spherical iron oxides were produced. Our investigation demonstrated that hydrochloric acid is effective as an absorption liquid. We also determined the optimal absorption liquid composition and heating time. The iron content analysis results obtained using this method were consistent with those from the microwave digestion method, showing a relative standard deviation of 6 %. For the duration of the pretreatment, the microwave digestion method required 1 day, whereas the oxygen-flask combustion method required a significantly shorter period of time (2–3 hour). Furthermore, the results from the addition and recovery experiments for Al, Ti, Cr, Mn, Ni, Co, Cu, Zn, and Mo indicated high values for Al and low values for Ti and Mn, with the values for the other elements indicating a recovery rate surpassing 90 %.