Graphene Composites with Cobalt Sulfide: Efficient Trifunctional Electrocatalysts for Oxygen Reversible Catalysis and Hydrogen Production in the Same Electrolyte
Graphene Composites with Cobalt Sulfide: Efficient Trifunctional Electrocatalysts for Oxygen Reversible Catalysis and Hydrogen Production in the Same Electrolyte
复制标题
石墨烯与硫化钴复合材料：高效三功能电催化剂，用于同一电解质中氧可逆催化和制氢
DOI：
10.1002/smll.201701025
复制
发表时间：
2017-09-06
期刊：
影响因子：
13.3
通讯作者：
Chen, Shaowei
中科院分区：
文献类型：
--
作者：
Wang, Nan;Li, Ligui;Chen, Shaowei
以硝酸钴和硫脲为原料，在氨气气氛中对石墨烯氧化物进行简单热处理，合成了含Co9S8的氮硫共掺石墨烯复合材料(NS/rGO-Co)。值得注意的是，在0.1mKOH水溶液中，最佳样品的析氧反应活性优于基准RuO2催化剂，氧还原反应活性与商业铂碳相当，析氢反应的过电位仅为-0.193 V，达到10 mA cm(-2)。在0.1mKOH溶液中，OR的半波电位与OER中的10 mA cm(-2)的电位之差仅为0.700 V，而在同一电解液中，要达到10 mA cm(-2)才能达到10 mA cm(-2)。目前的三官能团催化活性明显好于最近文献报道的结果，其中显著的三官能团活性归因于N，S共掺杂的RGO和Co9S8纳米粒子之间的协同作用。这些结果突出了精心设计的结构工程在制备多功能电化学反应催化剂方面的重要性。
Nitrogen and sulfur-codoped graphene composites with Co9S8 (NS/rGO-Co) are synthesized by facile thermal annealing of graphene oxides with cobalt nitrate and thiourea in an ammonium atmosphere. Significantly, in 0.1 m KOH aqueous solution the best sample exhibits an oxygen evolution reaction (OER) activity that is superior to that of benchmark RuO2 catalysts, an oxygen reduction reaction (ORR) activity that is comparable to that of commercial Pt/C, and an overpotential of only -0.193 V to reach 10 mA cm(-2) for hydrogen evolution reaction (HER). With this single catalyst for oxygen reversible electrocatalysis, a potential difference of only 0.700 V is observed in 0.1 m KOH solution between the half-wave potential in ORR and the potential to reach 10 mA cm(-2) in OER; in addition, an overpotential of only 450 mV is needed to reach 10 mA cm(-2) for full water splitting in the same electrolyte. The present trifunctional catalytic activities are markedly better than leading results reported in recent literature, where the remarkable trifunctional activity is attributed to the synergetic effects between N,S-codoped rGO, and Co9S8 nanoparticles. These results highlight the significance of deliberate structural engineering in the preparation of multifunctional electrocatalysts for versatile electrochemical reactions.