Pourbakhsh Zahra-Sadat, Mohammadi Kyana, Moshaii Ahmad, Azimzadehirani Maryam, Hosseinmardi Amir
Department of Physics, Tarbiat Modares University P.O Box 14115-175 Tehran Iran
Department of Chemistry, Tarbiat Modares University P.O Box 14115-175 Tehran Iran.
RSC Adv. 2019 Oct 7;9(55):31860-31866. doi: 10.1039/c9ra05155d.
We have investigated the effect of deposition of a α-FeO thin layer on a substrate of TiO nanoparticles for photoelectrochemical (PEC) water splitting. The TiO layer was coated on an FTO substrate using the paste of TiO nanoparticles. The α-FeO layer was deposited on the TiO thin film, using the method of Successive Ionic Layer Adsorption and Reaction (SILAR) with different cycles. Various characterizations including XRD, EDX and FE-SEM confirm the formation of α-FeO and TiO nanoparticles on the electrode. The UV-visible absorption spectrum confirms a remarkable enhancement of the absorption of the α-FeO/TiO/FTO composite relative to the bare TiO/FTO. In addition, the photocurrents of the composite samples are remarkably higher than the bare TiO/FTO. This is mainly due to the low band gap of α-FeO, which extends the absorption spectrum of the α-FeO/TiO composite toward the visible region. In addition, the impedance spectroscopy analysis shows that the recombination rate of the charge carriers in the α-FeO/TiO is lower than that for the bare TiO. The best PEC performance of the α-FeO/TiO sample was achieved by the sample of 70 cycles of α-FeO deposition with about 7.5 times higher photocurrent relative to the bare TiO.
我们研究了在TiO纳米颗粒基底上沉积α-FeO薄层对光电化学（PEC）水分解的影响。使用TiO纳米颗粒浆料将TiO层涂覆在FTO基底上。采用连续离子层吸附与反应（SILAR）方法，通过不同的循环次数在TiO薄膜上沉积α-FeO层。包括XRD、EDX和FE-SEM在内的各种表征证实了电极上α-FeO和TiO纳米颗粒的形成。紫外-可见吸收光谱证实，相对于裸露的TiO/FTO，α-FeO/TiO/FTO复合材料的吸收有显著增强。此外，复合样品的光电流明显高于裸露的TiO/FTO。这主要是由于α-FeO的低带隙，它将α-FeO/TiO复合材料的吸收光谱扩展到了可见光区域。此外，阻抗谱分析表明，α-FeO/TiO中电荷载流子的复合率低于裸露的TiO。α-FeO沉积70次循环的样品实现了α-FeO/TiO样品最佳的PEC性能，其光电流相对于裸露的TiO高出约7.5倍。
