Nanostructured Fe,Co-Codoped MoO3 Thin Films

Olfa Kamoun,Mosbah Amlouk,Ruxandra Vidu,Mohamed Amara,Amel Mami

doi:10.3390/mi10020138

Abstract

Molybdenum oxide (MoO3) and Fe,Co-codoped MoO3 thin films obtained by spray pyrolysis have been in-depth investigated to understand the effect of Co and Fe codoping on MoO3 thin films. The effect of Fe and Co on the structural, morphological and optical properties of MoO3 thin films have been studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray analysis (EDAX), optical and photoluminescence (PL) spectroscopy, and electropyroelectric methods. The XRD patterns demonstrated the formation of orthorhombic α-MoO3 by spray pyrolysis. SEM characterization has shown an increase in roughness of MoO3 thin films by Fe and Co doping. Optical reflectance and transmittance measurements have shown an increase in optical band gap with the increase in Fe and Co contents. Thermal conductivity and thermal diffusivity of Fe,Co-doped MoO3 were 24.10–25.86 Wm−1K−1 and 3.80 × 10−6–5.15 × 10−6 m2s−1, respectively. MoO3 thin films have shown PL emission. Doping MoO3 with Fe and Co increases emission in the visible range due to an increase number of chemisorbed oxygen atoms. The photodegradation of an aqueous solution of methylene blue (MB) depended on the content of the codoping elements (Fe,Co). The results showed that a degradation efficiency of 90% was observed after 60 min for MoO3: Fe 2%-Co 1%, while the degradation efficiency was about 35% for the undoped MoO3 thin film.

Highlights

Nanosize molybdenum oxide has showed interesting applications
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Electropyrolytic measurements performed on the thin films have demonstrated a metallic character that is not so sensitive to the Fe:Co ratio in the doped films

Summary

Introduction

Nanosize molybdenum oxide has showed interesting applications. The investigation of α-MoO3 nanorods obtained by hydrothermal process has shown that nanorods of about 10 μm in length and 200–300 nm in diameter can be obtained. Photocatalysis technologies is the most promising for environmental purification and conversion of solar energy and ultra-violet (UV) [10,11,12,13] Multifunctional properties such as a combination of optical, semiconducting and catalytic of metal oxides (ZnO [14] and MoO3) thin films have been recently investigated. Molybdenum oxides are exciting materials with various applications such as optoelectronics, catalysis, sensors, superconductors, biosystems, and electrochromic systems These oxides are obtained in several stoichiometries, among which is the MoO3 stoichiometric compound with relatively wide bandgap energy This work presents photocatalytic behavior and physical investigations of MoO3 thin films codoped with iron and cobalt obtained by spray pyrolysis. Our goal to use thin films is making MoO3 with a rough surface that increases the specific surface and can be used for photocatalysis micromachines

Fe-Co Codoped MoO3 Thin Films Deposition

SEM-EDAX Characterization

Findings

Conclusions