Enhanced Water Oxidation Photoactivity of Nano-Architectured α-Fe2O3–WO3 Composite Synthesized by Single-Step Hydrothermal Method

• Published in: Journal of electronic materials 2018-04, Vol.47 (4), p.2359-2365
• Main Authors: Rahman, Gul, Joo, Oh-Shim, Chae, Sang Youn, Shah, Anwar-ul-Haq Ali, Mian, Shabeer Ahmad
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Electrodes; Electron microscopy; Electronics and Microelectronics; Fluorine; Hematite; Instrumentation; Iron oxides; Materials research; Materials Science; Nanocomposites; Nanorods; Optical and Electronic Materials; Oxidation; Photoelectric effect; Photoelectric emission; Scanning electron microscopy; Solid State Physics; Substrates; Tin oxides; Tungsten oxides; Visible spectrum
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-017-6059-7

This study reports the one-step in situ synthesis of a hematite–tungsten oxide (α-Fe 2 O 3 –WO 3 ) composite on fluorine-doped tin oxide substrate via a simple hydrothermal method. Scanning electron microscopy images indicated that the addition of tungsten (W) precursor into the reaction mixture altered the surface morphology from nanorods to nanospindles. Energy-dispersive x-ray spectroscopy analysis confirmed the presence of W content in the composite. From the ultraviolet–visible spectrum of α-Fe 2 O 3 –WO 3 , it was observed that absorption began at ∼ 600 nm which corresponded to the bandgap energy of ∼ 2.01 eV. The α-Fe 2 O 3 –WO 3 electrode demonstrated superior performance, with water oxidation photocurrent density of 0.80 mA/cm 2 (at 1.6 V vs. reversible hydrogen electrode under standard illumination conditions; AM 1.5G, 100 mW/cm 2 ) which is 2.4 times higher than α-Fe 2 O 3 (0.34 mA/cm 2 ). This enhanced water oxidation performance can be attributed to the better charge separation properties in addition to the large interfacial area of small-sized particles present in the α-Fe 2 O 3 –WO 3 nanocomposite film.