Influence of the annealing temperature on the formation of Mo17O47 and MoO3 nanoparticles and their Photocatalytic performances for the degradation of MB dye

Abstract

The present research article is about the visible light photocatalytic degradation of Methylene Blue (MB) by aqueous heterogeneous medium containing orthorhombic phase of nanocrystalline (NCs) molybdenum oxide (MoO3). The two different oxidation forms of molybdenum oxides formed at annealing temperatures of 90 °C and 400 °C are Mo17O47 and α-MoO3 nanocrystals which are found to exhibit good photocatalytic activity. In the present work, a simple conventional wet chemical method has been used to synthesize molybdenum oxide nanoparticles (NPs) by combining ammonium heptamolybdate tetrahydrate (AHMT) with capped sodium dodecyl sulfate (SDS) and ethanol solution. The orthorhombic phase is present in the samples annealed at 90 °C, 200 °C, 300 °C, and 400 °C, respectively, and it is found that the orthorhombic phase is a highly stable phase in both Mo17O47 and α-MoO3. The photocatalytic activity of the synthesized samples is estimated by using MB degradation. The photocatalytic behaviors of the synthesized Mo17O47 and α-MoO3 nanostructures have been studied using the color degradation of MB. It is found that Mo17O47 and α-MoO3 with nanorods like structure has the potential to degrade the MB dye and for a time of 90 min, the degradation efficiency of Mo17O47 and MoO3 are 56.15% and 95.78%, respectively.

Full text

Vol:.(1234567890)
Journal of Materials Science: Materials in Electronics (2020) 31:7378–7388
https://doi.org/10.1007/s10854-019-02820-w
1 3
Inuence oftheannealing temperature ontheformation of Mo17O47
and MoO3 nanoparticles andtheir Photocatalytic performances
forthedegradation ofMB dye
N.RajivChandar1 · S.Agilan1· R.Thangarasu2· N.Muthukumarasamy1· R.Ganesh3
Received: 17 August 2019 / Accepted: 26 December 2019 / Published online: 14 January 2020
© Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract
The present research article is about the visible light photocatalytic degradation of Methylene Blue (MB) by aqueous het-
erogeneous medium containing orthorhombic phase of nanocrystalline (NCs) molybdenum oxide (MoO3). The two different
oxidation forms of molybdenum oxides formed at annealing temperatures of 90°C and 400°C are Mo17O47 and α-MoO3
nanocrystals which are found to exhibit good photocatalytic activity. In the present work, a simple conventional wet chemical
method has been used to synthesize molybdenum oxide nanoparticles (NPs) by combining ammonium heptamolybdate tet-
rahydrate (AHMT) with capped sodium dodecyl sulfate (SDS) and ethanol solution. The orthorhombic phase is present in the
samples annealed at 90°C, 200°C, 300°C, and 400°C, respectively, and it is found that the orthorhombic phase is a highly
stable phase in both Mo17O47 and α-MoO3. The photocatalytic activity of the synthesized samples is estimated by using MB
degradation. The photocatalytic behaviors of the synthesized Mo17O47 and α-MoO3 nanostructures have been studied using
the color degradation of MB. It is found that Mo17O47 and α-MoO3 with nanorods like structure has the potential to degrade
the MB dye and for a time of 90min, the degradation efficiency of Mo17O47 and MoO3 are 56.15% and 95.78%, respectively.
1 Introduction
Over the years, MoO3 material has been studied for its use
in various applications. Several techniques are used to con-
trol the size of α-MoO3 nanocrystallites [1, 2]. In specific,
molybdenum oxide has attractive and unusual properties due
to its multiple valence states. It is used in diverse appli-
cations such as batteries, photodiode, electroluminescence
devices, superconductors, thermoelectric, electro chromic
devices, and also in photocatalytic application [3-7]. Molyb-
denum trioxide (MoO3) [8, 9] is known to exist in a variety
of oxidation and hydration states such as oxides, suboxides,
hydroxides, and crystalline hydrates. Depending upon the
nature of the application, an appropriate deposition method
is chosen for the growth of MoO3 NPs. The simple conven-
tional wet chemical method is generally used to synthesize
the MoO3 NPs. It is grown in the form of plates, needle,
stretched out columns, nanobelts, and nanorod-like mor-
phologies and are used for various applications. As a typical
N-type semiconductor, the physical and chemical properties
make this material more attractive to be used in different
applications. Many reports suggest that TiO2 is as an effec-
tive photocatalyst which can be used to degrade organic
pollutants due to its non-toxicity, photo-chemical stability,
fast absorption ability, and high reversibility [10]. However,
the wide optical band gap (~ 3.2eV) of TiO2 facilitates the
degradation only with the UV light. So it is necessary to
search for the materials which can use the inexpensive and
inexhaustible solar energy visible light and act as photocata-
lysts [11, 12].
1D orthorhombic phase MoO3 has a unique behavior
owing to its tunnel structure with excellent photo-physical
and photo-chemical properties compared to hexagonal and
monoclinic α-MoO3. α-MoO3 NPs is a suitable light-driven
photocatalyst having an optical band gap that lies in the vis-
ible light region (2.8–3.0eV) [13] and it directly absorbs
light photons. In order to effectively degrade dye molecules,
visible light irradiation acts as a strapping oxidant. However,
* N. Rajiv Chandar
nrajiv81@gmail.com
1 Department ofPhysics, Coimbatore Institute ofTechnology,
Coimbatore, TamilNadu641014, India
2 Department ofPhysics, PSG College ofArts & Science,
Coimbatore, TamilNadu641014, India
3 Department ofPhysics, Sri Krishna College ofTechnology,
Coimbatore, TamilNadu641042, India
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