Effects of In Situ Co or Ni Doping on the Photoelectrochemical Performance of Hematite Nanorod Arrays
Effects of In Situ Co or Ni Doping on the Photoelectrochemical Performance of Hematite Nanorod Arrays
复制标题
原位Co或Ni掺杂对赤铁矿纳米棒阵列光电化学性能的影响
DOI：
10.3390/app10103567
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发表时间：
2020-05-01
影响因子：
2.7
通讯作者：
Li, Xiuwei
中科院分区：
文献类型：
--
作者：
Cheng, Feng;Li, Xiuwei
特色应用本文报道的材料可用作光电化学电池的光阳极，将水分解为氢气和氧气。摘要采用水相化学法在掺氟氧化锡（FTO）导电玻璃上制备了Co掺杂和Ni掺杂的α-Fe 2 O3纳米棒阵列。原位掺杂）。采用X射线衍射（XRD）、扫描电子显微镜（SEM）、紫外-可见分光光度法、线性扫描伏安法和Mott-Schottky（M-S）测试等手段对样品进行了表征。结果表明，在α-Fe_2 O_3中引入5%Co或Ni（掺杂剂与Fe的摩尔比为1：20），并没有改变其晶相、形貌、能隙和平带电位。未掺杂和掺杂的α-Fe_2 O_3的直接带隙为2.24 eV，间接带隙为1.85 eV，平带电位为-0.22 V（相对于饱和甘汞电极（SCE））。在0.2 V vs. SCE的外加电位下，Co掺杂和Ni掺杂的α-Fe_2 O_3的光电流分别为1.28 mA/cm（2）和0.79 mA/cm（2），分别是未掺杂α-Fe_2 O_3的2.1倍和1.3倍。在Co或Ni掺杂之后，电荷载流子浓度分别从1.65 × 10（25）m（-3）增加到3.74 × 10（25）m（-3）和2.50 × 10（25）m（-3）。因此，掺杂的α-Fe 2 O 3的光电流的增加可能归因于它们增强的导电性。
Featured ApplicationThe material reported in this article can be used as a photoanode of a photoelectrochemical cell that splits water into hydrogen and oxygen. In this way, solar energy can be converted into hydrogen energy.Abstract Co-doped and Ni-doped hematite (alpha -Fe2O3) nanorod arrays were prepared on fluorine-doped tin oxide (FTO) conductive glass via aqueous chemical growth, in which the doping and the formation of nanorods occurred simultaneously (i.e., in situ doping). These samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet (UV)-visible spectrophotometry, linear sweep voltammetry and Mott-Schottky (M-S) measurement. Results showed that the introduction of 5% Co or Ni into alpha -Fe2O3 (the molar ratio of dopant to Fe is 1:20) did not change its crystal phase, morphology, energy gap and flat band potential. Both the undoped and the doped alpha -Fe2O3 showed a direct band gap of 2.24 eV, an indirect band gap of 1.85 eV, and a flat band potential of -0.22 V vs. saturated calomel electrode (SCE). At an applied potential of 0.2 V vs. SCE, the Co-doped and the Ni-doped alpha -Fe2O3 exhibited a photocurrent of 1.28 mA/cm(2) and 0.79 mA/cm(2), respectively, which were 2.1 times and 1.3 times that of the undoped alpha -Fe2O3. After the Co or Ni doping, the charge carrier concentration increased from 1.65 x 10(25) m(-3) to 3.74 x 10(25) m(-3) and 2.50 x 10(25) m(-3), respectively. Therefore, the increase in the photocurrent of the doped alpha -Fe2O3 was likely attributed to their enhanced conductivity.