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本论文采用空气煅烧与氮气/氨气退火两步法制备了α-Fe2O3/N-CNTs和γ-Fe2O3/N-CNTs高效氧气还原反应催化剂.X射线衍射与X射线光电子能谱等结果显示:球状的α-Fe2O3与立方体状的γ-Fe2O3较好地分散在氮掺杂的碳纳米管上;不同的退火温度造成γ-Fe2O3/N-CNTs中氮的掺杂量约为1.06%,而α-Fe2O3/N-CNTs中氮掺杂量约为1.94%.从拉曼光谱结果发现,α-Fe2O3/N-CNTs的ID/IG值(1.26)大于γ-Fe2O3/N-CNTs的ID/IG值(1.18),说明α-Fe2O3/N-CNTs表面可因较大的碳缺陷程度而产生更多的氧还原活性电位.电化学性能表征结果再次印证:相比较于γ-Fe2O3/N-CNTs,N-CNTs和CNTs,α-Fe2O3/N-CNTs具有更低的氧还原起始电位(-0.21 V)和峰值电位(-0.27 V).在碱性条件下,氧气在α-Fe2O3/N-CNTs表面更易发生接近4电子的还原反应.另外,与Pt/C相比,α-Fe2O3/N-CNTs和γ-Fe2O3/N-CNTs皆具有较好的催化耐久性与稳定性,进一步显示了二者在清洁能源电池领域的应用价值与潜力.
In this thesis, α-Fe2O3 / N-CNTs and γ-Fe2O3 / N-CNTs high efficient oxygen reduction catalysts were prepared by two steps of air calcination and nitrogen / ammonia annealing.The results of X-ray diffraction and X-ray photoelectron spectroscopy showed that: The spherical α-Fe2O3 and cubic γ-Fe2O3 are well dispersed on the nitrogen-doped carbon nanotubes. The doping amount of nitrogen in γ-Fe2O3 / N-CNTs is about 1.06% due to the different annealing temperature The results show that the ID / IG value of α-Fe2O3 / N-CNTs (1.26) is larger than that of γ-Fe2O3 / N-CNTs by Raman spectroscopy IG value (1.18), indicating that the surface of α-Fe2O3 / N-CNTs can produce more oxygen reduction activity potential due to the larger degree of carbon defects.Results of electrochemical characterization confirmed that: Compared with γ-Fe2O3 / N- CNTs, CNTs and CNTs, α-Fe2O3 / N-CNTs have a lower initial potential of -0.21 V and a peak potential of -0.27 V. Under alkaline conditions, Compared with Pt / C, both α-Fe2O3 / N-CNTs and γ-Fe2O3 / N-CNTs have better catalytic durability and stability than N-CNTs, Shows both in the field of clean energy batteries The value and potential.