氮掺杂石墨烯用于碱性燃料电池产过氧化氢

Nitrogen-doped graphene for making hydrogen peroxide in alkaline fuel cell

以天然石墨(G)为原料,苯胺为含氮前驱体,采用Hummers法、原位引发苯胺聚合以及在氮气中高温热处理制备了氮掺杂石墨烯(N-G)。借助X射线衍射(XRD)、傅里叶转换红外光谱(FT-IR)、透射电子显微镜(TEM)、低温氮气吸脱附(BET)、热分析方法(TG-DSC)和电化学测试等手段对N-G的组成、结构、形貌和电化学性能等进行表征分析和评价。结果表明,在氮气中高温热处理聚苯胺修饰的氧化石墨烯(GO)能够有效地对其进行还原和氮掺杂,获得的N-G具有微孔结构,比表面积达到167.6 m^2/g,显示出高的热稳定性;在三电极体系中,N-G在0.1 mol/L KOH中催化氧气还原反应(ORR)的起始电势为0.89 V,主要以2电子反应途径进行,生成H_2O_2的选择性达到75%~95%,并且产生的电流密度较大。

Nitrogen-doped graphene（ N-G） is prepared by using natural graphite and aniline as start material and nitrogen-containing precursor,using Hummers method,in-situiniation aniline polymerization together with high temperature heat treatment in nitrogen gas. The composition,structural properties,morphology and electrochemical performances are characterized and evaluated by X-ray diffraction（ XRD）. Flourier transformation infrared spectroscopy（ FT-IR）,transmission electron microscopy（ TEM）,low temperature nitrogen adsorption-desorption analysis（ BET）,thermogravimetry-differential scanning calorimetry（ TG-DSC） and electrochemical tests. The results indicate that graphene oxide（ GO） after high temperature heat treatment in nitrogen gas and polyaniline modification can be reduced and doped effectively. The obtained N-G owns microporous structure with specific surface area reaching 167. 6 m^2/g,revealing high thermal stability. With the N-G as cathodic catalyst in three-electrode system,the oxygen reduction reaction（ ORR） mainly proceeds in a two-electron pathway with 0. 89 V of onset potential in 0. 1 mol/L KOH solution;the selectivity towards hydrogen peroxide reaches 75%-95% and it generates high current density.