基于CaC2低温制备金属碳化物/石墨烯复合物与高效氧气析出反应性能研究

Mild Synthesis of Metal Carbides on Few-layer Graphene from CaC2 for Efficient Oxygen Evolution Reaction

碳化钙(CaC2)用于制备碳材料、金属碳化物吸引了众多研究者的关注,但通常情况下需采用高温处理。首次报道了在较低温度(室温)下,球磨CaC2与金属盐可直接制备超小尺寸的金属碳化物。所合成的Ni、Fe、Co碳化物的转化机理为碳化钙中具有还原性C22-和氧化金属阳离子(M2+)之间的氧化还原反应。同时伴随复杂的氧化还原反应和哑铃状C≡C失去电荷、重构形成高石墨度的碳材料(即为石墨烯),原位形成的多层石墨烯材料可以作为良好的导电基底,用于电化学反应研究。值得注意的是,Ni-C-G复合材料表现出了优异的催化氧气析出反应性能。此结果可进一步支持其他金属碳化物-石墨碳复合材料的可控合成及广泛的电化学应用。

Calcium carbide(CaC2)represents one fascinating material for the fabrication of carbon and metal carbides,yet hightemperature treatment was commonly used.Herein,we reported for the first time that small-sized metal carbides could be derived from CaC2 at mild conditions such as ball milling at room temperature.Ni/Fe/Co carbides were successfully demonstrated,and the underneath conversion mechanism was revealed to be redox chemistry in between reductive C22-and oxidative metal cations(M2+).Besides,the complex redox chemistry and reconfiguration of electron-depleted C≡C dumbbells further enable the in-situ formation of highly graphitized carbon that can serve as excellent conductive substrate.Remarkably,the Ni-C-graphitic carbon composite exhibited excellent catalytic performance towards oxygen evolution reaction.Our method is believed potentially supporting the facile synthesis of other metal carbide-graphitic carbon composites as well as diverse electrochemical applications.