Talibawo Joan, Kyesmen Pannan I, Cyulinyana Marie C, Diale Mmantsae
African Centre of Excellence in Energy and Sustainable Development, University of Rwanda, KN 67 Street Nyarugenge, P.O. Box 3900, Kigali 4285, Rwanda.
Department of Physics, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa.
Nanomaterials (Basel). 2022 Aug 27;12(17):2961. doi: 10.3390/nano12172961.
In this work, we report the effect of zinc (Zn) and nickel (Ni) co-doping of hydrothermally synthesized hematite nanorods prepared on fluorine-doped tin oxide (FTO) substrates for enhanced photoelectrochemical (PEC) water splitting. Seeded hematite nanorods (NRs) were facilely doped with a fixed concentration of 3 mM Zn and varied concentrations of 0, 3, 5, 7, and 9 mM Ni. The samples were observed to have a largely uniform morphology of vertically aligned NRs with slight inclinations. The samples showed high photon absorption within the visible spectrum due to their bandgaps, which ranged between 1.9-2.2 eV. The highest photocurrent density of 0.072 mA/cm at 1.5 V vs. a reversible hydrogen electrode (RHE) was realized for the 3 mM Zn/7 mM Ni NRs sample. This photocurrent was 279% higher compared to the value observed for pristine hematite NRs. The Mott-Schottky results reveal an increase in donor density values with increasing Ni dopant concentration. The 3 mM Zn/7 mM Ni NRs sample produced the highest donor concentration of 2.89 × 10 (cm), which was 2.1 times higher than that of pristine hematite. This work demonstrates the role of Zn and Ni co-dopants in enhancing the photocatalytic water oxidation of hematite nanorods for the generation of hydrogen.
在本工作中，我们报道了在氟掺杂氧化锡（FTO）衬底上通过水热法合成的锌（Zn）和镍（Ni）共掺杂赤铁矿纳米棒对增强光电化学（PEC）水分解的影响。将赤铁矿纳米棒种子以3 mM的固定浓度和0、3、5、7和9 mM的不同浓度的镍进行简便掺杂。观察到样品具有垂直排列的纳米棒的大致均匀形态，略有倾斜。由于其带隙在1.9 - 2.2 eV之间，样品在可见光谱内显示出高光子吸收。对于3 mM Zn/7 mM Ni纳米棒样品，在1.5 V对可逆氢电极（RHE）时实现了最高光电流密度0.072 mA/cm²。该光电流比原始赤铁矿纳米棒观察到的值高279%。莫特 - 肖特基结果表明，随着镍掺杂剂浓度的增加，施主密度值增加。3 mM Zn/7 mM Ni纳米棒样品产生的最高施主浓度为2.89×10¹⁹（cm⁻³），比原始赤铁矿高2.1倍。这项工作证明了锌和镍共掺杂剂在增强赤铁矿纳米棒光催化水氧化以产生氢气方面的作用。
