STRUCTURAL STABILITY AND ELECTRON-ENERGY STATE OF THE H2SO4 GRAPHITE DEINTERCALATION COMPOUNDS

We present experimental results on stage stability and stage transition in H2SO4-GDICs by X-ray measurements, and electronic energy state by UV/VIS spectrophotometer measurements. From the results of X-ray measurements, it is shown that the changes of stage and d(c) value are irregular and occur randomly, and that the penetration of H2O molecules into the intercalated H2SO4 layers and oxidation cause the deintercalation of HSO4- from the interlayers of H2SO4-GICs, resulting in the disordered stages of H2SO4-GDICs. The results of UV/VIS spectrophotometer measurements show that the minimum values of reflectance move gradually to the lower energy slate with deintercalation time and increase in value slowly, and that the H2SO4-GDICs are relatively stable up to the sixth week in H2SO4 solutions. This study provides information on the intercalated HSO4- content and the stability of H2SO4-GICs during the deintercalation process.