Green synthesized N-doped graphitic carbon sheets coated carbon cloth as efficient metal free electrocatalyst for hydrogen evolution reaction

Jebakumar Immanuel Edison, Thomas Nesakumar,Atchudan, Raji,Karthik, Namachivayam,Lee, Yong Rok Elsevier 2017 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.42 No.21

<P><B>Abstract</B></P> <P>Heteroatom doped carbon structures received a great attention owing to its applications in catalysis, energy and optics. In this work, a simple hydrothermal approach for the synthesis of nitrogen doped graphitic carbon sheets (N-GCSs) is reported. <I>Rubus parvifolius</I> (<I>R. parvifolius</I>) fruit juice and aqueous ammonia are used as carbon precursor and nitrogen dopant, respectively. The synthesized N-GCSs are characterized using Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy, high resolution transmission electron microscopy (HR-TEM) and field emission scanning electron microscopy (FE-SEM) coupled with energy dispersive spectrum (EDS). The presence of hydroxyl and carbonyl functionalities in the synthesized N-GCSs are confirmed by the FT-IR analysis. The doping of nitrogen in N-GCSs is revealed through the XPS spectrum. The XRD and Raman studies imply that the synthesized N-GCSs are moderate graphitic nature. The FE-SEM and HR-TEM images of N-GCSs exposed its sheet like porous morphology. The electrocatalytic activity of N-GCSs coated carbon cloth (N-GCSs/CC) are examined towards hydrogen evolution reaction (HER) in 0.50 M H<SUB>2</SUB>SO<SUB>4</SUB> using linear sweep voltammetry (LSV), Tafel and electrochemical impedance spectroscopy (EIS) studies. The onset potential of synthesized N-GCSs/CC is about −0.25 V<SUB>RHE</SUB>, which is lower than that of bare carbon cloth (CC) −0.75 V<SUB>RHE</SUB>. The Tafel slope of N-GCSs/CC is smaller (198 mV dec<SUP>−1</SUP>) than that of bare CC (253 mV dec<SUP>−1</SUP>), suggested fast kinetics of N-GCSs. Moreover, the N-GCSs/CC is attained −10 mA cm<SUP>−2</SUP> of current density at very low over potential of −0.320 V<SUB>RHE</SUB>. The EIS studies also proved the excellent catalytic activity of N-GCSs/CC towards HER. Thus, the <I>R. parvifolius</I> derived N-GCSs is a better candidate for HER in acidic medium.</P> <P><B>Highlights</B></P> <P> <UL> <LI> N-doped graphitic carbon sheets (N-GCSs) were prepared by <I>Rubus parvifolius</I> fruit. </LI> <LI> N-GCSs coated carbon cloth (CC) shows good electrocatalytic activity towards HER. </LI> <LI> The onset potential of N-GCSs/CC is about −0.25 V<SUB>RHE</SUB>. </LI> <LI> Tafel slope of N-GCSs/CC is smaller (198 mV dec<SUP>−1</SUP>) than bare CC. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Residues of Endosulfan and its Metabolites in a Rice Field of Madurai, India

JEBAKUMAR, S.R.D. 한국환경농학회 2001 한국환경농학회지 Vol.20 No.5

Thirty-day-old rice seedlings, IR-20 variety were transplanted into the experimental plots and were sprayed with endosulfan (35% EC) after 52 days at the rate of 0.64 kg a.i/ha. Residues of endosulfan in the plant, soil, and water were found to decrease steadily upto 15 days. A second application of the pesticide was made on the 31st day and the plant was harvested on 56th day after the first application. The residue level on hay and grains was 0.7 ㎍/g. This level is seven times higher than FAO/WHO-prescribed tolerance level of 0.1 ㎍/g. Metabolites of endosulfan were traced out in plants, soil, and water during the pre- and post-harvest period.

Facile synthesis of carbon encapsulated RuO₂ nanorods for supercapacitor and electrocatalytic hydrogen evolution reaction

Jebakumar Immanuel Edison, Thomas Nesakumar,Atchudan, Raji,Lee, Yong Rok Elsevier 2019 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.44 No.4

<P><B>Abstract</B></P> <P>In this work, carbon encapsulated RuO<SUB>2</SUB> nanorods (RuO<SUB>2</SUB> NRs/C) has been synthesized by thermolysis of ruthenium chloride and <I>Punica granatum</I> (<I>P. granatum</I>) peel under N<SUB>2</SUB> atmosphere. The synthesized RuO<SUB>2</SUB> NRs/C was characterized using Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction method (XRD), field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) with energy dispersive spectroscopy (EDS) analyses. The FT-IR results suggested that the organic constituents of <I>P. granatum</I> have been carbonized and encapsulated over RuO<SUB>2</SUB> nanorods (RuO<SUB>2</SUB> NRs). The XRD pattern of RuO<SUB>2</SUB> NRs/C revealed its crystalline nature and carbon encapsulation. The synthesized RuO<SUB>2</SUB> NRs/C has been well dispersed with the average width of 20 nm, exposed from the FE-SEM and HR-TEM images. The EDS results of RuO<SUB>2</SUB> NRs/C showed the existence of three elements viz., Ru, O and C. Further, the supercapacitor and electrocatalytic hydrogen evolution reaction (HER) activities of RuO<SUB>2</SUB> NRs/C were studied using standard electrochemical methods. The synthesized RuO<SUB>2</SUB> NRs/C offered a maximum specific capacitance of 151.3 F g<SUP>−1</SUP> at a scan rate of 5 mV s<SUP>−1</SUP>, obtained from the cyclic voltammetry results. The onset over potential and Tafel slope of synthesized RuO<SUB>2</SUB> NRs/C for HER were −0.099 V<SUB>RHE</SUB> and −99.4 mV dec<SUP>−1</SUP>, respectively. The present study revealed that RuO<SUB>2</SUB> NRs/C as a better candidate for supercapacitor and HER.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Carbon encapsulated RuO<SUB>2</SUB> nanorods (RuO<SUB>2</SUB> NRs/C) were synthesized by simple thermolysis. </LI> <LI> RuO<SUB>2</SUB> NRs/C shows good supercapacitor and electrocatalytic HER activity. </LI> <LI> RuO<SUB>2</SUB> NRs/C offered a maximum specific capacitance of 151.3 F g<SUP>−1</SUP> at 5 mV s<SUP>−1</SUP>. </LI> <LI> The onset potential and Tafel slope of RuO<SUB>2</SUB> NRs/C for HER were −0.099 V<SUB>RHE</SUB> and −99.4 mV dec<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Prevalence of Antibiotics in Nectar and Honey in South Tamilnadu, India

RD. Jebakumar Solomon,V. Satheeja Santhi,Vimalan Jayaraj 한국통합생물학회 2006 Animal cells and systems Vol.10 No.3

Prevalence of Antibiotics in Nectar and Honey in South Tamilnadu, India

Solomon, RD. Jebakumar,Santhi, V. Satheeja,Jayaraj, Vimalan The Korean Society for Integrative Biology 2006 Integrative biosciences Vol.10 No.3

Reverse-Phase High-performance Liquid Chromatography (RP-HPLC) based technique is one of the most sensitive techniques to detect the antibiotics present in honey. In the southern part of Tamilnadu, India, majority of the farmlands are occupied by plantations such as coconut, banana and rubber. A variety of antimicrobial compounds and antibiotics, which have been reported in pollen, nectar and other floral parts of the plant, gets accumulated in honey through honeybees (Apis mellifera). We have collected the nectar samples from banana (Musa paridasiaca) and rubber (Ficus elastica) flowers and the honey from honey hives of banana and rubber cultivated areas. The extracted nectar and honey samples are subjected to RP-HPLC analysis with authentic antibiotic standards. Nectar and honey samples showed 4-17, 11-29 ${\mu}g/kg$ of streptomycin, 2-29, 3-44 ${\mu}g/kg$ of ampicillin and 17-34, 26-48 ${\mu}g/kg$ of kanamycin respectively.

Corrosion inhibition performance of spermidine on mild steel in acid media

Edison, Thomas Nesakumar Jebakumar Immanuel,Atchudan, Raji,Pugazhendhi, Arivalagan,Lee, Yong Rok,Sethuraman, Mathur Gopalakrishnan Elsevier 2018 Journal of molecular liquids Vol.264 No.-

<P><B>Abstract</B></P> <P>The corrosion inhibition and adsorption behavior of spermidine on mild steel (MS) in 1 M sulfuric and 0.50 M hydrochloric acid have been investigated at room temperature by electrochemical methods viz., electrochemical impedance spectroscopy (EIS) and Tafel polarization techniques. The adsorption of spermidine on MS is studied by Langmuir adsorption isotherm, Fourier transform infrared (FT-IR) spectroscopy and density functional theory (DFT) analysis. The Tafel results imply that, spermidine behaves mixed mode inhibitor and the corrosion inhibition efficiency increases with increasing of spermidine concentration. The EIS results exposed that, the formation of adsorptive layer of spermidine increase the charge transfer resistance and subsequent drop in the double layer capacitance of MS in acids. The calculated free energy of adsorption (ΔG) for spermidine in HCl and H<SUB>2</SUB>SO<SUB>4</SUB> are −31.92 and −30.48 kJ mol<SUP>−1</SUP> which suggested the physical along with chemical mode of adsorption of inhibitor. The formation of inhibitive protection layer on MS is confirmed by FT-IR spectroscopy. The correlation of corrosion inhibition performance and molecular structure of spermidine is discussed by DFT method. All the results showed that spermidine is an excellent corrosion inhibitor for MS in both H<SUB>2</SUB>SO<SUB>4</SUB> and HCl acids.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The acid corrosion inhibition performance of spermidine on mild steel was evaluated. </LI> <LI> The spermidine act as mixed mode inhibitor revealed by Tafel studies. </LI> <LI> Spermidine adsorbed on mild steel and effectively retards corrosion. </LI> </UL> </P>

Binder-free electro-synthesis of highly ordered nickel oxide nanoparticles and its electrochemical performance

Edison, Thomas Nesakumar Jebakumar Immanuel,Atchudan, Raji,Lee, Yong Rok Elsevier 2018 ELECTROCHIMICA ACTA Vol.283 No.-

<P><B>Abstract</B></P> <P>In this work, highly ordered nickel oxide nanoparticles were electrochemically synthesized on nickel foam (NiO<SUB>x</SUB> NPs/Ni foam) via the formation and subsequent heat treatment of nickel hydroxide. The synthesized NiO<SUB>x</SUB> NPs were characterized using Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) with elemental analysis and high resolution transmission electron microscopy (HR-TEM). The XRD results revealed the presence of two different oxide phases with high crystallinity. The synthesized NiO<SUB>x</SUB> NPs were highly ordered spherical morphology with average size of 7 nm, identified from the FE-SEM images. Further, the electrochemical performance of synthesized NiO<SUB>x</SUB> NPs/Ni foam was evaluated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge discharge (GCD) methods. The calculated specific capacity of NiO<SUB>x</SUB> NPs/Ni foam was found to be 219 C/g (60.7 mAh/g) at scan rate of 5 mV/s. This present work implies that the electro-synthesized NiO<SUB>x</SUB> NPs/Ni foam as a good binder-free, highly stable battery-type material and it can be used as a positive electrode for hybrid-capacitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Highly ordered NiO<SUB>x</SUB> nanoparticles were synthesized on Ni foam by cathodic electrodeposition. </LI> <LI> The average size of the NiO<SUB>x</SUB> NPs was about 7 nm with spherical shape. </LI> <LI> The electro-synthesized NiO<SUB>x</SUB> NPs shows good electrochemical performance in 2 M aqueous KOH. </LI> <LI> The NiO<SUB>x</SUB> NPs showed a maximum specific capacity of 219 C/g (60.7 mAh/g) at 5 mV/s. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Direct electro-synthesis of MnO₂ nanoparticles over nickel foam from spent alkaline battery cathode and its supercapacitor performance

Edison, Thomas Nesakumar Jebakumar Immanuel,Atchudan, Raji,Karthik, Namachivayam,Xiong, Dangsheng,Lee, Yong Rok Elsevier 2019 JOURNAL- TAIWAN INSTITUTE OF CHEMICAL ENGINEERS Vol.97 No.-

<P><B>Abstract</B></P> <P>This work reports the recovery of manganese ions from spent primary alkaline battery (PAB) cathode, subsequent anodic electro-synthesis of MnO<SUB>2</SUB> nanoparticles on Ni foam (MnO<SUB>2</SUB> NPs/Ni foam) for supercapacitors. The as-fabricated MnO<SUB>2</SUB> NPs/Ni foam is characterized by common optical and surface analytical techniques. The X-ray diffraction (XRD) of MnO<SUB>2</SUB> NPs/Ni foam matches well with γ-MnO<SUB>2</SUB> NPs pattern and hence the synthesized MnO<SUB>2</SUB> NPs mainly exist in γ-phase. The synthesized MnO<SUB>2</SUB> NPs are mostly in spherical cluster shape with an average size of 15 nm, inferred from the scanning electron microscopic (SEM) images. The X-ray photoelectron spectroscopy (XPS) result reveals that, synthesized MnO<SUB>2</SUB> NPs embraces with two different oxidation states such as 4<SUP>+</SUP> (MnO<SUB>2</SUB>) and 3<SUP>+</SUP> (MnOOH). The MnO<SUB>2</SUB> NPs/Ni foam delivers a maximum specific capacity of 549 F/g at the scan rate of 5 mV/s in three electrodes aqueous K<SUB>2</SUB>SO<SUB>4</SUB> system. Further, the two electrode asymmetric supercapacitor device is constructed with MnO<SUB>2</SUB> NPs/Ni foam as a positive and commercial graphene nanoplatelets coated Ni foam (GNP/Ni foam) as a negative electrode. The assembled supercapacitor device yields a maximum specific capacitance of 105 F/g at 5 mV/s, which achieves a maximum energy density of 14.7 Wh/kg at the power density of 748.9 W/kg between 0 and 1.5 V of working potential. This effort may pave the way for recovery and utilization of spent PAB cathode materials for energy storage devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This work presents simple method for the recovery and utilization of Mn<SUP>2+</SUP> from spent alkaline battery cathode. </LI> <LI> The average size of the MnO<SUB>2</SUB> NPs was about 15 nm with spherical cluster shape. </LI> <LI> The electro-synthesized MnO<SUB>2</SUB> NPs revealed good electrochemical performance in K<SUB>2</SUB>SO<SUB>4</SUB>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Ultrasonic synthesis, characterization and energy applications of Ni–B alloy nanorods

Edison, Thomas Nesakumar Jebakumar Immanuel,Atchudan, Raji,Karthik, Namachivayam,Sethuraman, Mathur Gopalakrishnan,Lee, Yong Rok Elsevier 2017 Journal of the Taiwan Institute of Chemical Engine Vol.80 No.-

<P><B>Abstract</B></P> <P>Alloy nanostructures had received much attention for their applications in energy, catalysis, and optics. This paper described a facile ultrasonic approach for the synthesis of Ni–B alloy nanorods (Ni–B NRs). The crystallinity, chemical state, surface area and surface morphology of Ni–B NRs were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N<SUB>2</SUB> adsorption–desorption isotherms and high-resolution transmission electron microscopy (HR–TEM) analyses, respectively. The electrocatalytic behavior of Ni–B NRs toward the oxygen evolution reaction (OER) was studied by linear sweep voltammetry (LSV) and Tafel polarization methods in 0.1 M aqueous KOH. The LSV results of Ni–B NRs showed very low OER onset potential of 1.44 V<SUB>RHE</SUB> with an overpotential of 212 mV<SUB>RHE</SUB>. The Ni–B NRs attained 10 mA/cm<SUP>2</SUP> of current density at a very low potential of 1.61 V<SUB>RHE</SUB> than bare SS (1.87 V<SUB>RHE</SUB>) and bare Pt (2.50 V<SUB>RHE</SUB>). Further, Ni–B NRs showed a low Tafel slope of 45 mV/dec when compared to other standard materials, revealed the fast OER kinetics. The calculated specific capacitance of synthesized Ni–B NRs was 581 F/g, from the results of cyclic voltammetry at a scan rate of 2 mV/s. The electrocatalytic and supercapacitor studies exposed that the synthesized Ni–B NRs can be used as an electrocatalyst for OER as well as pseudocapacitor for commercial electric vehicles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Amorphous Ni–B alloy nanorods (Ni–B NRs) are synthesized by ultrasonic method. </LI> <LI> Ni–B NRs shows excellent electrocatalytic activity toward OER than Ru and Ir. </LI> <LI> Ni–B NRs exhibit good pseudocapacitor behavior in aqueous KOH. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Biogenic Synthesis of Silver Nanoparticles Using Cnidium officinale Extract and Their Catalytic Reduction of 4-Nitroaniline

Edison, Thomas Nesakumar Jebakumar Immanuel,Baral, Ek Raj,Lee, Yong Rok,Kim, Sung Hong Springer-Verlag 2016 Journal of cluster science Vol.27 No.1

<P>Silver nanoparticles (AgNPs) with two different morphologies were synthesized using aqueous extract of Cnidium officinale rhizomes under different reaction conditions and applied to the facile aqueous phase reduction of 4-nitroaniline (4-NA) as catalysts. The synthesized AgNPs are characterized by UV-Visible spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) method and high resolution transmission electron microscopy (HR-TEM) with energy dispersive X-ray spectroscopy (EDS) analysis. HR-TEM showed that the synthesized AgNPs had two different morphological forms; truncated triangular prism shapes with a mean size of similar to 35 nm and spherical shapes with a mean size of similar to 9 nm. The HR-TEM and XRD results are consistent with the standard values. The catalytic activities of both AgNPs were compared on the reduction of 4-NA in water by NaBH4 as a reducing agent. The reduction of 4-NA was monitored using UV-Visible spectroscopy. The similar to 9 nm (spherical) sized AgNPs showed superior catalytic activity than the larger AgNPs. The calculated rate constant (k) for the catalytic reduction of 4-nitroanilie by spherical AgNPs was 11.16 x 10(-3) s(-1).</P>