Preparation of sulfur-doped graphite by solid-state microwave method: The effect of reaction conditions on the sulfur-doping process

The high-quality sulfur-doped graphite (SGi) was prepared from concentrated sulfuric acid-graphite intercalation compounds (H 2 SO 4 -GICs) by solid-state microwave irradiation, where H 2 SO 4 was the sulfur (S) source and S-doping occurred within a minute. The preparation of H 2 SO 4 -GICs was a key step for S-doping and exfoliation process. Notably, it was found that S-doping was influenced by the dosage of H 2 SO 4 , where the lower dosage of H 2 SO 4 was beneficial for the S-doping. The exfoliation efficiency was greatly affected by the temperature and dosage of oxidant, where lower temperature and lower dosage of KMnO 4 guaranteed efficient exfoliation.