Ni-doped Fe 2 O 3 thin films which were active photoanodes for water splitting were prepared by electrodeposition. By adjusting Ni molar ratios (Ni/(Ni + Fe)) in the electrolyte, Fe 2 O 3 thin films with various compositions of Ni could be tuned. The films were characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, atomic absorption spectrophotometer, and UV–vis spectroscopy. The highest photo-response obtained from Fe 2 O 3 doped with 2.08 mol.% Ni is 1.5 mA/cm 2 at 0.65 V vs. Ag/AgCl in 1.0 M NaOH solution. The high performance is attributed to the improvement of charge transport properties and retardation of the charge recombination resulting from the dopants in the lattice. The optical absorption spectra of the films reveal that the bandgaps of the Ni-doped Fe 2 O 3 films are approximately 1.9–2.2 eV for all samples regardless of their doping level. XPS shows that the concentration of Ni is much higher on the surface than that in bulk.
Luo Song,Jie Xiaohua,Zheng Qiongbin,Zhang Liuyan,Wu Huishu,Huang Xiaoye
In this work, we have presented a detailed study on the effect of shot peening on anodization of medium carbon steel. Anodization has been conducted on both non-shot-peened and shot-peened steel. The results show that shot peening procedure facilitates the subsequent anodization significantly. The mechanism for promoting anodization by shot peening has been discussed. After anodization, the shot-peened steel forms an amorphous α-Fe 2 O 3 film with a geometric pattern. More importantly, the α-Fe 2 O 3 film and the shot-peened layer constitute an anodized shot-peened layer, which exhibits a multi-scale structure. Due to this multi-scale structure, the anodized shot-peened layer shows a controllable wettability. It can be used as a hydrophilic or a hydrophobic coating.
A non-enzyme photoelectrochemical (PEC) glucose sensor based on α-Fe 2 O 3 film is investigated. The α-Fe 2 O 3 film was fabricated via a simple spin coating method. The proposed glucose sensor exhibits good selectivity, a fast response time of <5 s, a linear range of 0.05 to 6.0 mM, sensitivity of 17.23 μA mM −1 cm −2 and a detection limit of 0.05 μM. Meanwhile, the excellent performances of the α-Fe 2 O 3 sensor were obtained in reproducibility and the long-term stability under ambient condition. The linear amperometric response of the sensor covers the glucose levels in physiological and clinical for diabetic patients. Therefore, this non-enzyme PEC sensor based on α-Fe 2 O 3 film has a great potential application in the development of glucose sensors.
Conventionally, the surface-enhanced Raman spectroscopy (SERS) measurement is performed by dispersing noble metal nanoparticles onto the target sample directly or assembling noble metal nanoparticles onto a micro-sized substrate. Despite it is flourishing, this method is not adequate for various samples, mainly limited by either a defined confinement of the test position or the complex extraction process of the target sample on the irregularly shaped surface, besides the costive materials, complex and uncontrollable fabricating processes. Herein, we demonstrate that the α-Fe 2 O 3 thin film is decorated with Ag nanoparticles constructed on SiO 2 fibers as a flexible SERS-active substrate, which yields a functional optical enhancement of the signal at 532 nm laser excitation . It shows a high enhancement factor of 4.71 × 10 5 , ultrahigh sensitivity of 10 −15 M, and excellent signal stability with a relative standard deviation (RSD) of 1.22% and reproducibility with a RSD of 0.258%.
危险品化学品经营许可证（带存储）