Papers by Subramania Angaiah
Advanced Materials Technologies
The push towards reducing the size of portable/wearable electronics, wireless sensors, and the In... more The push towards reducing the size of portable/wearable electronics, wireless sensors, and the Internet of Things (IoT's) needs a critical requirement of miniaturized energy storage solutions. Typically, micro‐supercapacitors (MSC's) are the main key factors of electrochemical energy storage systems for those miniaturized device applications. Herein, a scalable screen printable flexible microsupercapcitor with highly flexible architecture is developed using a Prussian blue derived 3D‐penroseite (Ni,Co)Se2 nanocubes as the positive electrode and Ti3C2Tx MXene as the negative electrode. As a result, the printed flexible device delivered an enhanced active electrochemical site and a high areal capacitance of 63 mF cm−2 with a broad working potential range of 1.0 V. Furthermore, the (Ni,Co)Se2 || Ti3C2Tx based flexible MSC (FMSC) offered a remarkable energy density of 8.75 µWh cm−2 at a power density of 0.5 mW cm−2, making it an excellent microscale energy storage system for sm...
Bulletin of Materials Science, Dec 14, 2021
A rapid, efficient, green and eco-friendly approach for the preparation of reduced graphene oxide... more A rapid, efficient, green and eco-friendly approach for the preparation of reduced graphene oxide (rGO) using Plectranthus amboinicus (Indian borage) leaves extract (PAE) is explored in this study. The improvement in the reduction process was studied by varying the concentration of graphene oxide (GO), temperature and time duration. The physical and chemical properties of rGO are studied using Raman spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction (XRD) and field emission scanning electron microscope. The result obtained from XRD analysis confirms the removal of an oxygen-containing functional group of GO significantly by PAE. Raman analysis showed a higher ID/IG ratio for rGO (1.297) than GO (1.07), which indicates a higher level of disorder in the rGO with a decrease in the average size of the sp2 domain. From the electrochemical studies, a significant specific capacitance of 92.05 F g–1 (5 mV s–1) is obtained from the cyclic voltammetry (CV) curves and 73.20 F g–1 (0.1 A g–1) from the galvanostatic charge–discharge (GCD) curve.
Journal of Pharmaceutical and Biomedical Analysis, Feb 1, 2023
Materials Science and Technology, Jun 6, 2023
ES energy & environment, 2023
Sustainable Energy and Fuels, 2023
NiCo2O4 nanoparticles anchored onto 2D-carbyne nanosheets are prepared to use as a new nanohybrid... more NiCo2O4 nanoparticles anchored onto 2D-carbyne nanosheets are prepared to use as a new nanohybrid electrode to enhance the capacitive performance of hybrid supercapacitors.
Journal of Metallurgy and Materials Science, 2005
Journal of energy storage, Dec 1, 2022
Applied Nanoscience, Aug 5, 2022
International Journal of Polymeric Materials, May 18, 2022
Journal of Biomaterials Science-polymer Edition, Mar 9, 2022
With the thought and strong hope of uniqueness and challenging characteristic highlights and impo... more With the thought and strong hope of uniqueness and challenging characteristic highlights and importance of nanofibrous mats (NFMs) along with cyclodextrins (CDs) that having a significant opportunity, chances and handling a vital role in hostile to bacterial activities. For the most part, CDs are utilized to upgrade the antibacterial activity through the improvement of solubility, stability, and etc., to any molecule which can bring inside the CDs cavity via the formation of inclusion complexes. Polymer-mediated electrospun nanofibrous mats (PAN NFMs) are utilized as a nanocarrier for antibacterial activity in this article, utilizing nortriptyline (NP) as a reference molecule. As a result, NP forms an inclusion complex with β-Cyclodextrin (β-CD). As a result, the PAN NFMs are able to absorb it, thereby consolidating the complex NP on the nanofibrous surface. Additionally, the soaking of PAN NFMs in NP solution without β-CD was performed for comparison. To characterize the nanofibrous mats of NP/PAN and NP:β-CD-ICs/PAN NFMs, UV absorption, FTIR, Raman, XRD, and SEM techniques were used. The antibacterial activity of NP and NP:β-CD-ICs have been tried against positive control antibiotics by the disc diffusion method. Thus, the action has been improved for NP:β-CD-ICs/PAN NFMs over NP/PAN NFMs because of the solubility upgraded for the NP by the complexation of β-CD.
Inorganic chemistry frontiers, 2017
Redox activity of copper species immobilized poly(o-aminophenol)/multi-walled carbon nanotube for... more Redox activity of copper species immobilized poly(o-aminophenol)/multi-walled carbon nanotube for direct electrocatalysis towards detection of H2O2.
Journal of Molecular Liquids, Nov 1, 2021
Abstract Nanofibrous mats (NFMs) and cyclodextrins (CDs) play a vital role in drug releasing syst... more Abstract Nanofibrous mats (NFMs) and cyclodextrins (CDs) play a vital role in drug releasing systems. Generally CDs are used to enhance the drug release profile, water solubility, stability and so on to any molecule which can carry inside the CDs cavity through the formation of inclusion complexes. In this research paper, the benzocaine (BNC) is chosen as a reference drug molecule and electrospun PVdF nanofibrous mats (esPVdF NFMs) as a fibrous matrix to carry out the drug releasing ability. BNC is interacted with β-cyclodextrin (β-CD) to form an inclusion complexed product (BNC:β-CD-IC) and then PVdF NFMs is soaked in it to incorporate the inclusion complexed product on the surface. The soaking of PVdF NFMs in the BNC solution without β-CD is also carried out for a comparative study. Our aim was to analyze the drug release profile of BNC from BNC/PVdF and BNC:β-CD/PVdF NFMs. The characterization of BNC/PVdF NFMs in the presence and absence of β-CD is analysed with the help of UV–visible, fluorescence, lifetime decay, Fourier Transform InfraRed, Fourier Transform-Raman, powder X-Ray diffractogram and Scanning electron microscopic measurements. Selective stretching frequency of BNC molecule is changed for the NFMs with and without β-CD, evident the encapsulation of BNC into the β-CD cavity on the NFMs. SEM images showed that the BNC:β-CD is mostly occupied in the surface of the PVdF NFMs. Crystallinity of BNC is completely lost in both the NFMs. The release study of BNC in buffer solution elucidate that the PVdF/BNC:β-CD-IC NFMs have higher releasing ability of BNC than the BNC/PVdF NFMs due to the solubility enhancement of BNC by the complexation of β-CD.
Applied surface science advances, Sep 1, 2021
This work focuses on the influence of pulse reverse current parameters such as duty cycle and fre... more This work focuses on the influence of pulse reverse current parameters such as duty cycle and frequency on the microstructure and properties of graphene reinforced copper nanocomposite (Cu-Gr) coating. Graphene nanosheets were prepared by a liquid phase exfoliation technique and characterized using FE-SEM and Raman spectroscopy. Cu-Gr nanocomposite coating on stainless steel was prepared by pulse reverse electrodeposition method. The influence of pulse reverse current parameters such as duty cycle and frequency on the coating structure and texture was analyzed. By reducing the duty cycle and increasing frequency, a high amount of graphene co-deposition was achieved. A duty cycle of 40%, frequency of 1000 Hz and stirring speed of 500 rpm produced Cu-Gr coatings with maximum graphene codeposition. XRD analysis showed that the change in duty cycle and pulse frequency influenced the crystal structure, preferred orientation, and crystallite size of the deposit. A high pulse frequency improved the compactness of the composite coating, while longer pulse off-time and application of reverse pulse resulted in highly oriented (220) texture of pure Cu and Cu-Gr nanocomposite coatings. Due to graphene co-deposition, the copper grains became more refined, and hence the microhardness of the composite coating showed a tremendous increase compared to pure Cu coating. The Tafel polarization and electrochemical impedance studies revealed that pulse reverse electrodeposited Cu-Gr coating has higher corrosion resistance than pure Cu coating due to strong (220) texture and barrier effect of graphene.
Engineered science, 2021
In the present study, the effective removal of nitrates from the water was investigated using the... more In the present study, the effective removal of nitrates from the water was investigated using the nano alumina adsorbent and then the electrochemical method for the removal of nitrates using Pt anode and brass cathode were studied. Nano alumina has been used as an adsorbent to remove nitrates from aqueous solutions. The effects of contact time, adsorbent dosage and initial nitrate concentrations on the adsorption process have been investigated. The effects of pH and temperature on adsorption have been studied in order to optimize the range. Furthermore, the electrochemical method for the removal of nitrates using a Pt anode and a brass cathode has been observed to produce excellent results. The nitrate removal efficiency increases with electrolysis time in the current density range from 1 to 2 A dm-2. Maximum nitrate (NO3-) ions removal was achieved for nitrate (NO3-) ions concentrations of 200 mg/L after 90 minutes of electrolysis at a current density of 2 A dm-2. Direct nitrate reduction is possible at all nitrate concentrations and begins at a potential below 300 mV vs. saturated calomel electrode (SCE) in the cyclic voltammetry (CV) studies. From the CV and differential pulse stripping voltammetry (DPSV) studies, we have known that electrocatalytic reduction has a direct relationship between current and electrode potential. In CV, the electrode potential was found to be below 300 mV and DPSV showed that an electro-catalytic reduction occurred at a potential of 300 mV. From these studies, we infer that NO3ions are adsorbed on platinum electrode surfaces and desorbed from the surface. The adsorbed NO3ion is converted into NO2-(nitrite) ions on the electrode surface (this is the rate-determining step) and the NO2ion is converted into NO, N2O, and finally into N2 gas.
ACS omega, Dec 7, 2020
In this work, we report a novel hydrothermal synthesis of α-Fe 2 O 3 nanoleaf-incorporated mesopo... more In this work, we report a novel hydrothermal synthesis of α-Fe 2 O 3 nanoleaf-incorporated mesoporous carbonchitosan (α-Fe 2 O 3 @MPC-chit) as a versatile disposable sensor for selective electrochemical detection of nitrite and for supercapacitor applications. The newly synthesized α-Fe 2 O 3 @MPC-chit nanocomposite was characterized by scanning electron microscopy, Xray diffraction, Fourier transform-infrared spectroscopy, UV, and Raman spectroscopy. The extensive physicochemical characterization reveals the strong immobilization of α-Fe 2 O 3 nanoleaves within the MPC-chit composite. The electrochemical characterization with cyclic voltammetry and impedance spectroscopy using [Fe(CN) 6)] 3−/4− as a redox probe concludes good electron conductivity and efficient electron transfer behavior of α-Fe 2 O 3 @MPCchit. The α-Fe 2 O 3 @MPC-chit modified electrode exhibits excellent electrocatalytic activity toward nitrite oxidation. The amperometric method of nitrite detection showed a linear range of up to 200 μmol L −1. The current sensitivity and detection limit were found to be 0.913 μA μM −1 and 31 nM cm −2 , respectively. The improved catalytic activity of the proposed electrode was endorsed by the synergistic effect of α-Fe 2 O 3 with the MPC-chit composite. The ability of the proposed electrode was demonstrated by the successful detection of nitrite present in tap water, river water, and industrial samples with extensive recovery values. Furthermore, the α-Fe 2 O 3 @MPC-chit modified stainless-steel electrode showed high-performance supercapacitor application and exhibited a large specific capacitance of 380 F g −1 at 1 A g −1 .
Ceramics International, 2017
Pr 0.6 Sr 0.4 MnO 3 ± δ (PSM) nano crystalline powders were synthesized as cathode material by as... more Pr 0.6 Sr 0.4 MnO 3 ± δ (PSM) nano crystalline powders were synthesized as cathode material by assisted combustion method at intermediate temperature for 6 h using a novel aspartic acid as fuel. Thermal decomposition behaviour of the prepared nano powder was carried out by thermo gravimetric-differential thermal analysis. The crystallization behaviour and structural morphology of Pr 0.6 Sr 0.4 MnO 3 ± δ nano powder was investigated by Xray diffraction and SEM analysis. The average crystallite size was determined from X-ray line broadening analysis by using the Scherrer equation. This method remarkably reduced the synthesis time and temperature. The electrical conductivity of the sample was measured by the 'dc four probe' techniques in the temperature range of 500-800°C.
Journal of Solid State Electrochemistry, May 9, 2014
We prepared LiNi0.4Co0.6O2 nanofibers by electrospinning at the calcination temperature of 450 °C... more We prepared LiNi0.4Co0.6O2 nanofibers by electrospinning at the calcination temperature of 450 °C for 6 h. The prepared LiNi0.4Co0.6O2 nanofibers was characterized by thermal, X-ray diffraction, and Fourier transform infrared (FTIR) studies. The morphology of LiNi0.4Co0.6O2 nanofibers was characterized by scanning electron microscopy studies. The asymmetric supercapacitor was fabricated using LiNi0.4Co0.6O2 nanofibers as positive electrode and activated carbon (AC) as negative electrode and a porous polypropylene separator in 1 M LiPF6–ethylene carbonate/dimethyl carbonate (LiPF6–EC:DMC) (1:1 v/v) as electrolyte. Cyclic voltammetry studies were then carried out in the potential range of 0 to 3.0 V at different scan rates which exhibited the highest specific capacitance of 72.9 F g−1. The electrochemical impedance measurements were carried out to find the charge transfer resistance and specific capacitance of the cell, and they were found to be 5.05 Ω and 67.4 F g−1, respectively. Finally, the charge–discharge studies were carried out at a current density of 1 mA cm−2 to find out the discharge-specific capacitance, energy density, and power density of the capacitor cell, and they were found to be 70.9 F g−1, 180.2 Wh kg−1, and 248.0 W kg−1, respectively.
Thin Solid Films, Oct 1, 2008
Spinel lithium manganese oxide thin films were prepared on a stainless steel substrate by a spray... more Spinel lithium manganese oxide thin films were prepared on a stainless steel substrate by a spray pyrolysis method using a precursor solution of lithium acetate and manganese acetate in 1:1 (v/v) mixture of methanol and distilled water. Thermal analysis of the precursor solution was carried out for determining the required temperature for the phase formation or complete crystallization of the
Journal of King Saud University - Science, Jun 1, 2021
Synthetic dyes are widely used as coloring agents in the textile, food, paper, leather, and print... more Synthetic dyes are widely used as coloring agents in the textile, food, paper, leather, and printing industries. Sustainable removal of these dye molecules is a challenging task due to their toxic nature to the environment as well as for living organisms. In the present study, a simple hydrothermal method is carried out to synthesize reduced graphene oxide (rGO) using the leaves extract of Murraya koenigii. Further, different characterization techniques such as X-ray diffraction, Raman spectroscopy, UV-vis spectroscopy, and Fourier transform infrared spectroscopy (FT-IR) are used to confirm the physicochemical properties of synthesized rGO. Raman analysis confirms the reduction of graphene oxide by the increase in I D /I G ratio significantly. Field emission scanning electron microscopy (FE-SEM) and Transmission electron microscopy (TEM) analysis show well-exploited rGO morphology. Further, newly synthesized rGO is used as a photocatalyst for the removal of methylene blue (MB) and methyl orange (MO) dyes. UV-vis spectrophotometer is used for monitoring the degradation efficiency. Catalyst MKrGO shows 80% of MO and 77% of MB degradation within 120 min of sunlight exposure. The sustainability of this catalyst is checked by recyclability in five subsequent degradation cycles and noticed a stable and significant degradation activity.
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Papers by Subramania Angaiah