Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 44:383–388, 2014
Copyright ꢀ Taylor & Francis Group, LLC
C
ISSN: 1553-3174 print / 1553-3182 online
DOI: 10.1080/15533174.2013.771666
Effect of pH, L-Arginine Concentration, and Aging Time
on Selenium Nanostructures
K. Prabhu,1 K. Mohanraj,1 S. Kannan,1 S. Barathan,2 and G. Sivakumar3
1Department of Physics, Manonmaniam Sundaranar University, Tirunelveli, Tamil Nadu, India
2Department of Physics, Annamalai University, Annamalai Nagar, Tamil Nadu, India
3CISL, Department of Physics, Annamalai University, Annamalai Nagar, Tamil Nadu, India
have been prepared with the assistance of amino acid such as
L-cysteine and L-tyrosine.[3,4] To know to our knowledge, the
fabrication of L-arginine induced 1D selenium nanostructures
is not reported elsewhere. Hence, objective of the work is to
prepare 1D selenium nanostructures using SeO2 as Se source,
ascorbic acid as a reducing agent and L-arginine as a capping
agent by precipitation method.
Trigonal selenium nanoparticle is synthesized by precipitation
method using three L-arginine concentrations and ascorbic acid
and by varying aging time. In the XRD analysis, glassy nature of se-
lenium is identified (pH ≈ 2.8) and turned into hexagonal structure
at 2θ = 29.72◦ (pH = 7). Average size of the particle is 29–44 nm.
The FTIR result is confirmed the presence of selenium at 464 cm−1
and one-dimensional (1D) structural changes are detected in the
FESEM photographs. Energy gap is increased from 2.24–2.72 eV
up to 24 h aging time and then decreased about 2.41 eV at 48 h.
EXPERIMENTAL
In this study, the following chemicals such as selenium diox-
ide (SeO2), ascorbic acid (C6H8O6), L-arginine (C6H14N4O2),
sodium hydroxide (NaOH), and ethanol (C2H6O) were used. In
a typical synthesizing 500 mmol selenious acid (H2SeO3) was
obtained by dissolve the SeO2 in 50 mL of distilled water and
stirred for 10 min. Then 200 mmol L-arginine solution was pre-
pared by adding distilled water to the selenious acid solution.
The mixture of the two solutions was again stirred for 10 min
at room temperature to obtain complex solution. To obtain clear
colorless solution 1000 mmol NaOH solution was added drop
by drop. Finally, 300 mmol ascorbic acid solution was added
dropwise slowly into the solution. Color of the solution was
changed from transparent into brick red during the process. The
solution was again stirred for 1 h at room temperature. After
the stirring, the color of brick red color solution get changed
into dark red. Then the suspension was centrifuged and thor-
oughly washed using distilled water and ethanol three times
and obtained red selenium powder. Next, the selenium powder
was allowed to recrystallize using ethanol and to age for differ-
ent times by varying the aging time intervals about 3 h, 24 h,
and 48 h and obtained black gray particles. Again, the samples
were centrifuged and dried at room temperature. The samples
were grounded using mortar and pestle for further studies. The
above procedures were followed to prepare 300 and 400 mmol
L-arginine concentration.
Keywords L-arginine, nanorods, nanotubes, selenium
INTRODUCTION
Selenium is an important nonmetallic element, exhibiting a
large number of versatile properties, such as relatively a low
melting point, high photoconductivity, a high refraction co-
efficient (refractive index) in devices, and nonlinear optical
response, due to its characteristic structure, and it is widely
used in the fields of photo electric cells, photocopiers and so-
lar cells.[1] During the last few years, there has been grow-
ing interest in one dimensional nanostructures owing to their
novel electrical and optical properties, and potential applica-
tions in nanometer sized devices.[2] At recently, several authors
have prepared selenium nanostructures using different methods
such as chemical precipitation, the sonochemical, and the hy-
drothermal method.[1,3,4] The main aspects of amino acids in the
synthesis of nanomaterials are to control the shape, structure
of the particle and to prevent the agglomeration of nanopow-
der. Currently, one-dimensional (1D) selenium nanostructures
Received 10 January 2013; accepted 27 January 2013.
The authors express sincere thanks to the UGC-SAP, New Delhi, for
providing the financial support to the Department of Physics, Manon-
maniam Sundaranar University, Tirunelveli, Tamil Nadu, India. Also
the authors are thankful to authorities of the Manonmaniam Sundaranar
University, Tirunelveli, for providing the seed money project to carry
out the work.
Address correspondence to K. Mohanraj, Department of Physics,
Manonmaniam Sundaranar University, Tirunelveli-627 012, Tamil
Nadu, India. E-mail: kmohanraj.msu@gmail.com.
Powder X-ray diffraction (XRD) measurements were per-
formed using PANalytical XPERT PRO diffractometer with Cu
Kα radiation (λ = 1.5406 Å) in the range from 10◦ to 80◦.
FTIR spectra were recorded in the region 4000–400 cm−1 us-
ing Perkin-Elmer FTIR spectrometer (model RX1) with the
resolution 4 cm−1. Photographs of the 1D Se nanostructures
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