One-Pot Purification and Iodination of Waste Kish Graphite into High-Quality Electrocatalyst
Kish graphite, a waste (called dust) from a steelmaking process, can be simultaneously purified and functionalized by mechanochemical ball-milling in the presence of iodine. The resultant iodinated Kish graphite (I-Kish-G) contains low content of impurities and high iodine content (1.83 at%, 16.17 wt%, energy dispersive X-ray spectroscopy) with high crystallinity. It has high specific surface area (924.3 m2 g-1), indicating that I-Kish-G is significantly purified, functionalized, and exfoliated into a few graphitic layers. More importantly, I-Kish-G displays outstanding electrocatalytic activity for oxygen reduction reaction with long-term durability and robustness against methanol crossover and CO poisoning effects in alkaline media.