Localized photoelectrochemistry on a tungsten oxide-iron oxide thin film material library.

نویسندگان

  • Jan Philipp Kollender
  • Andrei Ionut Mardare
  • Achim Walter Hassel
چکیده

A WO3-Fe2O3 thin film combinatorial library was fabricated using a vapor phase co-deposition method followed by a combined thermal annealing and oxidation process. The scanning electron microscopy (SEM) analysis of the library microstructure combined with X-ray diffraction (XRD) investigations suggested that α-Fe2O3 grains preferentially grow from boundaries of domains, containing finer grains of WO3 and Fe2WO6, forming filiform networks on the surface. The surface density of the hematite networks depends on the amount of Fe present in the library. Photocurrents measured at different applied biases using Photo Electrochemical Scanning Droplet Cell Microscopy (PE-SDCM) were analyzed and mapped along the entire compositional spread. A distinctive photocurrent peak was detected at 21.9 atom % Fe, and its appearance was correlated to the higher amount of hematite present in the library at this specific composition together with a specific WO3 crystallographic orientation ((222) orthorhombic or (400) monoclinic). This finding is confirmed by qualitative and quantitative XPS surface analysis at the photocurrent peak position in the material library. Thus the enhancement of the photocurrent cannot be exclusively attributed to certain surface modifications since only hematite was found on the library surface at the peak composition.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Designing and Fabrication of Electrochromic Windows Using Tungsten Oxide Films Prepared Through Sol-gel Coating on a Glass

In this study, a sol-gel peroxotungstic acid sol was employed to deposit tungsten oxide (WO3) films by the spin-coating technique. In view of smart window applications, electrochromic windows were then designed and fabricated using a thin tungsten oxide film. For this purpose, Glass/ FTO/ WO3/ electrolyte/ FTO/Glass could be of use due to its special structure that consists of an electrochromic...

متن کامل

Preparation and Characterization of WO3 Electrochromic Films Obtained by the Sol-Gel Process

Tungsten trioxide (WO3) films have been coated on indium thin oxide (ITO) conductive glass substrate, using aqueous solution of peroxotungstic acid (PTA) by the sol-gel dip coating method. X-ray diffractometery (XRD) analysis confirmed monoclinic and triclinic structure for the film and powdered WO3 respectively. Fourier transforms infrared spectroscopy (FT-IR) exhibit...

متن کامل

Fabrication of Graphene Oxide Thin Films on Transparent Substrate via a Low-Voltage Electrodeposion Technique

Graphene oxide (GO) thin films were simply deposited on fluorine doped tin oxide (FTO) substrate via a low-voltage electrodeposition. The GO and GO thin films were characterized by Zeta Potential, X-ray diffraction, Ultraviolet-Visible spectroscopy, atomic force microscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy and energy dispersive X-ray spectrosc...

متن کامل

Thin Film Heterogeneous Ion Exchange Membranes Prepared by Interfacial Polymerization of PAA-co-Iron-Nickel Oxide Nanoparticles on Polyvinylchloride Based Substrate

In this research thin film heterogeneous cation exchange membrane was prepared by interfacial polymerization of polyacrylic acid-co-iron nickel oxide nanoparticle son PVC based substrate. Spectra analysis confirmed graft polymerization conclusively. The SEM images showed that polymerized layer covers the membranes by simple gel network entanglement. Results exhibited that membrane water content...

متن کامل

Synthesis of Zinc Oxide Nanostructured Thin Film by Sol- Gel Method and Evaluation of Gas Sensing Properties

Ethanol (C2H6O) sensitivity of zinc oxide (ZnO) thin film has been studied in present work. Semiconductor thin films of zinc oxide (ZnO) were deposited onto alkali-free glass substrates by the sol–gel method and dip-coating technique. The ZnO sol was synthesized by dissolving zinc acetate dehydrate in ethanol, and then adding Tetra ethanol-amine.  The as-coated films were preheated at 150 ºC fo...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • ACS combinatorial science

دوره 15 12  شماره 

صفحات  -

تاریخ انتشار 2013