K JAYAPRAKASH
Articles written in Bulletin of Materials Science
Volume 44 All articles Published: 8 September 2021 Article ID 0247
G A SUGANYA JOSEPHINE K JAYAPRAKASH G MEENAKSHI A SIVASAMY G NIRMALA DEVI R N VISWANATH
ZnO-flaky-like nanoflowers with enhanced photocatalytic activity were synthesized by a new hydrothermal technique. The material was characterized and the photocatalytic studies were conducted under solar light irradiation for a model azo dye, Orange G. The material was compared with ZnO nanosphere and nanorod. The results showed the particle size of the nanostructures as a nanorod is 62–81 nm, as a nanosphere is 40–70 nm and as flaky nanoflowers is 20–30 nm (thickness of the flake). The photocatalytic activity showed an enhanced 2-fold increase in the activity for nanoflowers when compared to nanorods and spheres. The Brauner–Emmett–Teller results showed that the nanoflowers (14.197 m$^2$ g$^{-1}$) had a higher surface area nearly 3.5 times when compared to the nanospheres (4.06 m$^2$ g$^{-1}$) and seven times with nanorods (2.1 m$^2$ g$^{-1}$) which is the possibility of such high photocatalytic activity. The smaller particle size and the arrangement of nanoflowers play an important role in enhanced photocatalytic activity.
Volume 45 All articles Published: 14 June 2022 Article ID 0106
G A SUGANYA JOSEPHINE K JAYAPRAKASH A SIVASAMY
Nanosized, rectangularly arranged ZnO–CeO$_2$ nanoflowers were prepared by a simple hydrothermal technique. The prepared nanocomposites were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), UV–visible differential reflectance spectroscopy, field-emission scanning electron microscope, X-ray photoelectron spectroscopy, electron paramagnetic resonance and Brunauer-Emmett-Teller techniques. Different compositions of composites were prepared and the best composition was used for conducting the photocatalytic studies. The degradation of 2,4-dichlorophenoxy acetic acid (2,4-D), a herbicide and endocrine-disrupting agent, was performed under visible-light irradiation. The results showed the nanocomposite to be in a flower-like structure comprising of rectangular-shaped ZnO on which CeO$_2$ particles were evenly distributed. This flower-shaped ZnO–CeO$_2$ nanorectangulate composite comprises particle sizes ranging from 50–100 nm of rectangular thickness and 10–20 nm spherical particles. The XRD and FT-IR results prove the presence of ZnO and CeO$_2$ in the prepared nanocomposite. The bandgap energy was found to be 3.18 eV. X-ray photoelectron spectroscopy proved the presence of Ce as Ce$^{4+}$ (CeO$_2$) in the prepared composite. A comparative study of nanocomposite and pristine ZnO showed increased activity. The photocatalytic preliminary and kinetic studies were conducted. The reaction followed pseudo-first-order kinetics. The UV–visible absorption spectrum and chemical oxygen demand decrease proved the complete degradation of the endocrine disruptor 2,4-D under visible-light irradiation.
Volume 46, 2023
All articles
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Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020
Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
Physical Sciences 2020
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