Browsing by Author "Muhiuddin, M."

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A study on solubility of bismuth cations in nickel cobalt ferrite nanoparticles and their influence on dielectric and magnetic properties
(Elsevier Ltd, 2023) Patil, S.; Meti, S.; Kanavi, P.S.; Bhajantri, R.F.; Anandalli, M.; Mondal, R.; Karmakar, S.; Muhiuddin, M.; Rahman, M.R.; Kumar, B.C.; Hegde, B.G.
In this work, a low temperature (∼600 °C) solution combustion technique is employed for the synthesis of Ni0.5Co0.5BixFe2-xO4 (NCBFO, where x = 0.0, 0.05, 0.1, 0.15, & 0.2) nanoparticles with crystallite size variation of 17–22 nm. The X-ray diffraction (XRD) technique is used to confirm the formation of cubic spinel phase of Bi3+ doped (for x ≤ 0.05 samples) nickel–cobalt ferrite (NCFO) nanoparticles. The increase in bismuth substitution (x > 0.05) results in the formation of the Bi2O3 along with the NCFO structure, which results in the reduction of binding energy and is confirmed by the XRD and X-ray photoelectron spectroscopy (XPS) techniques. From the Raman spectra, the change in the intensities of the peaks is observed due to the variation of Bi3+ in NCFO matrix. Due to increasing cation concentration and electronegativity, the FTIR absorption band shifts toward the lower wave numbers. Dielectric measurements were carried out to examine the charge transport behavior and electric conduction mechanism. The FESEM images shows the non-magnetic bismuth atoms are diffused into the NCFO nanoparticles. From the vibrating sample magnetometer (VSM) analysis, it is observed that saturation magnetization, remanent magnetization, coercivity and squareness ratio are found to be maximum for x = 0.15 NCBFO sample. The high coercivity (Hc = 916.8 Oe) for the x = 0.15 sample indicates the hard ferromagnetic behaviour of the samples. © 2023 Elsevier B.V.
Cost effective synthesis of sulfur and nitrogen co-doped graphene aerogel and application in binder free supercapacitor
(American Institute of Physics, 2024) Muhiuddin, M.; Khan, A.Z.; Devi, N.A.; Bharadishettar, N.; Meti, S.; Siddique, A.B.; Bhat K, U.; Akhtar, W.; Rahman, M.R.
Incorporating heteroatoms into graphene lattice results in enhanced electrical conductivity and electrochemically active sites and has significant importance in developing high-performance supercapacitors. In this study, sulfur and nitrogen co-doped graphene aerogel is synthesized via hydrothermal technique followed by a simple but effective freeze-thawing and ambient pressure drying process (referred to as SN-GA). The process requires low-cost raw materials and cost-effective equipment without the utilization of any special instrument that operates at ultra-low temperatures, under high pressure, or vacuum environment. Ammonium sulfate [(NH4)2SO4] and ethylenediamine are used as a source of sulfur and nitrogen and as a reducing agent. (NH4)2SO4 with different molarities (0, 12, 24, and 36 mM) are used to synthesize four different aerogel samples marked as GA, SN-GA1, SN-GA2, and SN-GA3. The electrode is prepared using an SN-GA2 sample, exhibiting an outstanding specific capacitance of 244 F g−1 at an applied current density of 1 A g−1 with almost 98.5% Coulomb efficiency. Furthermore, based on the SN-GA2 sample, the symmetrical supercapacitor is fabricated, displaying an energy density of 18.14 Wh kg−1 at a power density of 498.4 W kg−1. Hence, SN-GA2 renders a promising material for supercapacitor applications. © 2024 Author(s).
Efficiency enhancement in dye-sensitized solar cells through neodymium-doped graphene quantum dot-modified TiO? photoanodes
(Elsevier B.V., 2025) Senadeera, G.K.R.; Weerasekara, W.M.S.K.; Jaseetharan, T.; Sandunika, P.U.; Kumari, J.M.K.W.; Dissanayake, M.A.K.L.; Muhiuddin, M.; Rahman, M.R.; Bhat K, U.; Akhtar, M.W.; Udayakumar, U.; Siddique, A.B.; Ekanayake, P.
This study explored the effects of Neodymium-doped graphene quantum dots (NdGQDs) on improving the performance efficiency of TiO2 based dye-sensitized solar cells (DSSCs). By employing in-situ physical assisted mixing, DSSCs with optimized NdGQDs in TiO2 photoanodes showed a power conversion efficiency of 8.76 %, a significant improvement compared to the 6.01 % efficiency of pristine TiO2-based DSSCs under 100 mW cm?2 illumination (AM 1.5). Notably, the short-circuit current density increased by 74 %. HRTEM analysis revealed that the NdGQDs have a size range of approximately 7–9 nm. UV–visible spectroscopy and Mott-Schottky analysis revealed a positive shift in the Fermi level, promoting better electron transfer and increased photocurrent density at the expenses of the open circuit voltage. Electrochemical impedance spectroscopy characterization of DSSCs incorporating NdGQD-modified photoanodes revealed a reduction in electron transfer resistance at the photoanode|dye|electrolyte interface, accompanied by an increase in recombination resistance within the device suppressing the electron recombination rate. © 2024 Elsevier B.V.
Exploring MIL-101 (Cr) and Its Polymeric Composites as Potential Adsorbents for Volatile Iodine from Nuclear Off-gas: A Detailed Experimental and Computational Study
(American Chemical Society, 2025) Kolay, S.; Kancharlapalli, S.; Samanta, S.; Muhiuddin, M.; Jha, P.; Pagare, A.; Mishra, R.
Owing to the rapid growth of nuclear energy as a sustainable, affordable, and clean energy source, the entrapment of radioactive iodine released from the nuclear off-gas stream is considered a vital concern. We view MOFs as potential futuristic adsorbents for this remedy. Herein, we examined the gravimetric iodine adsorption characteristics of radiation and chemically stable MIL-101(Cr) and its polymeric composites with variation of temperatures. The saturation adsorption capacity shown by pristine MIL-101(Cr) is 4.1 g I2 g-1, and the saturation capacity of composites varies based on MIL-101(Cr)’s concentrations. MIL-101(Cr)@PES 2:1 shows an uptake capacity of 2.1 g I2 /gbead, which is ? 350% superior to the reported HKUST-1@PES and ?150% higher compared to MOF-808@PVDF0.7. Based on various spectroscopic studies and DFT calculations, probable host-guest interactions leading to enhanced I2 adsorption have been elucidated. The open Cr metal site acts as the initial adsorption site for I2 that gets converted into iodide and afterward to higher polyiodide through the transfer of charge from the host matrix. These findings suggest that MIL-101(Cr) can be considered one of the potential alternate adsorbents for radioactive iodine. © 2025 American Chemical Society.
Fabrication of Î²-Phase PVDF/MWCNTs Nanofibers on a Flexible Substrate for Energy Harvesting Application
(Institute of Electrical and Electronics Engineers Inc., 2024) Chauhan, S.S.; Sharma, S.; Muhiuddin, M.; Rahman, M.R.
It is challenging to deposit the pristine polyvinylidene difluoride (PVDF) in Î² crystalline phase on a flexible substrate since pristine PVDF exists in the Î±-phase. This paper presents a novel formation of nanofibers membrane of PVDF in which multiwall carbon nanotubes (MWCNT) is added as the composite in PVDF for transformation from Î± to Î² phase. The PVDF/MWCNTs nanofibers is electro spun after adding carboxyl functionalized MWCNT with PVDF to form the Î² phase. The field emission scanning electron microscope (FE-SEM) is used to characterize the presence of the nanofiber's membrane. X-ray diffraction (XRD) is used to characterize the Î² phase and Fourier-transform infrared spectroscopy (FTIR) is used to detect the functionalized bonds in the formation of PVDF/MWCNTs nanofibers on a flexible Polyethylene Terephthalate (PET). The measurement of the polarization of electric field hysteresis shows good characteristics with Ps, Pr, and EC are 9.58 Î¼C/m2, 4 Î¼C/m2, and 1 MV/m, respectively. The optimized film has a high potential for application as the piezoelectric material in energy harvesting devices fabricated on a flexible PET film. Â© 2024 IEEE.
Facile and rapid method to synthesis sulfur and nitrogen co-doped graphene quantum dots as an electrode material with excellent specific capacitance for supercapacitors application
(Elsevier Ltd, 2024) Muhiuddin, M.; Devi, N.A.; Bharadishettar, N.; Meti, S.; Siddique, A.B.; Satyanarayan, M.N.; Udaya, B.K.; Akhtar, W.; Rahman, M.R.
The current invention pertains to the expeditious simple synthesis of electrode materials that improve the storage capacity of supercapacitors (SCs). Sulfur and nitrogen co-doped graphene quantum dots (SN-GQDs) are synthesized using a microwave-assisted hydrothermal (MAH) process at low pressure and with a short reaction time. The utilization of SN-GQDs in conjunction with Polyaniline (PANI) has the potential to enhance the supercapacitor's energy and power density, owing to their notable specific capacitance. Implementing SN-GQDs material as an SCs electrode, exhibiting an outstanding specific capacitance of 1040 F/g at an applied current density of 0.5 A g−1. Furthermore, a composite of SN-GQDs/PANI is synthesized and the electrochemical performance is compared with the as-synthesized PANI. The symmetrical SCs are fabricated using SN-GQDs/PANI composite, and PANI. At a current density of 0.5 A g−1 SN-GQDs/PANI composite-based SC displays a superior energy density of 44.25 Wh/kg at a power density of 1.227 kW/kg. This is high in comparison to PANI-based SC which shows an energy density of 18.71 Wh/kg at 0.8 kW/kg power density at the same current density. The SC created using SN-GQDs/PANI composite exhibits superior properties and is a promising material for SC applications. © 2024 Elsevier B.V.
Ge-doped 3D flower-like Cu2SnS3 structures for enhanced lithium-ion storage performance
(Elsevier Ltd, 2025) Appu, S.; Anusha, B.R.; Udayabhanu; Muhiuddin, M.; Rahman, M.R.; Kalappa, K.
Development of advanced anode materials with high capacity and stable cycling performance is crucial for next-generation lithium-ion batteries. In this work, we report Ge-doped three-dimensional flower-like Cu2SnS3 (Ge-CSS) microstructures synthesized via a solvothermal route. The introduction of Ge into the Cu?SnS? lattice effectively enhances electrical conductivity and lithium-ion transport, leading to superior electrochemical properties. The Ge-CSS electrode delivers a high initial discharge capacity of 796 mAh/g at 0.1 A/g with improved cycling stability, retaining 354 mAh/g after 100 cycles, and exhibits excellent rate capability, maintaining 74.09 % capacity as the current density increases from 0.1 to 2 A/g. Moreover, the reduced charge transfer resistance compared to undoped Cu2SnS3 highlights the beneficial role of Ge incorporation. These findings demonstrate the potential of Ge-CSS microstructures as a promising anode material for high-performance lithium-ion batteries. © 2025 Elsevier Ltd
Investigation of structural, thermal, magnetic, and dielectric properties of Yb+3 doped nickel cobalt ferrite nanomaterial for electro-magnetic applications
(Springer, 2024) Patil, S.; Meti, S.; Anandalli, M.; Badiger, H.; Bhajantri, R.F.; Pratheek, L.; Muhiuddin, M.; Rahman, M.R.; Hegde, B.G.
Herein, we report the synthesis of ytterbium (Yb) (with concentration x = 0.01, 0.015, 0.02, 0.025 and 0.03) doped in to nickel cobalt ferrite (NCYFO: YbxNi0.5Co0.5Fe2-xO4) nanoparticles at temperature 500 °C with phase pure spinel using solution combustion technique. The phase purity and effect of doping on NCYFO complex oxide on structural, thermal, magnetic and dielectric properties have been determined by various characterization techniques. The FTIR data reveal that strong metal oxide linkages can be observed in the tetrahedral and octahedral sites at wavenumbers 460 to 410 cm−1 and 595 to 540 cm−1. The X-ray diffraction (XRD) studies confirmed the spinel structure. The crystallite sizes and lattice parameters were estimated to be in the range of 31 to 22 nm and 8.32 to 8.35 Å, respectively. The X-ray photoelectron spectroscopy (XPS) study confirmed that the increase in Yb concentration results in accumulation of Yb in the grain boundaries of NCYFO in the form of Yb2O3. The thermal stability of nanoparticles were investigated using TGA/DSC method. Transmission Electron microscopy (TEM) studies and Field emission scanning electron microscopy (FESEM) used to study the particle size distribution and elemental composition within the nanomaterial. In addition, the dielectric properties, such as, dielectric constant and dielectric loss were investigated for all the NCYFO nanomaterial. The saturation magnetization of the NCYFO is determined using vibrating sample magnetometer (VSM) analysis and is maximum for x = 0.03 (Ms = 97.56 emu/g) sample. The high magnetic behaviour and better dielectric properties of the NCYFO nanomaterials are suitable for electro-magnetic applications. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.
Neodymium doped graphene quantum dots/PANI composite for supercapacitor application
(Elsevier Ltd, 2025) Muhiuddin, M.; Bharadishettar, N.; Devi, N.A.; Gautam, A.; Chauhan, S.S.; Siddique, A.B.; Ahmad, M.I.; Satyanarayan, M.N.; K, U.B.; Akhtar, W.; Rahman, M.R.
The publication presents a streamlined and economical technique for fabricating advanced electrode materials to enhance the energy storage capabilities of supercapacitors (SCs). The focus is on synthesizing neodymium-doped graphene quantum dots (Nd-GQDs) via a microwave-assisted hydrothermal (MAH) process. This method uses microwave irradiation's rapid heating and efficient energy transfer under low pressure and minimal reaction time. The resulting Nd-GQDs exhibit enhanced electrochemical properties, including increased capacitance and improved charge storage, making this approach practical and effective for advancing supercapacitor technology. An exceptional specific capacitance of 618 F g?1 at a 5 mV s?1 scan rate is demonstrated using Nd-GQDs as the SC electrode material. Due to their high specific capacitance, Nd-GQDs, when combined with polyaniline (PANI), improve the energy and power density of SCs. Nd-GQDs/PANI composites with varying amounts of Nd-GQDs in symmetric SCs are fabricated to demonstrate their promising properties for SC applications. SCs fabricated with 20 mL of Nd-GQDs in the PANI matrix showed a superior specific capacitance of 354 F g?1 at a current density of 1 A g?1, while the energy density and power density were 49.15 Wh kg?1 and 2000 W kg?1, respectively. © 2025 Elsevier B.V.
Substrate-bias driven sputter deposited ?[jls-end-space/]-phase dominated tungsten film for spintronic applications
(Elsevier B.V., 2025) Rajawat, A.S.; Ahmad, N.; Nasril, R.; Sheikh, T.; Muhiuddin, M.; Sahu, S.; Gautam, A.; Kumar, A.; Ahmad, M.I.; Basheed, G.A.; Rahman, M.R.; Akhtar, W.
?[jls-end-space/]-Tungsten (?[jls-end-space/]-W), an A15 cubic phase of tungsten, exhibits a giant spin Hall angle compared to its bcc-phase ?[jls-end-space/]-Tungsten (?[jls-end-space/]-W), making high-quality ?[jls-end-space/]-W films desirable for spintronic applications. We report the controlled growth of ?[jls-end-space/]-W films on SiO2/Si substrates via DC sputtering, where substrate bias serves as a critical factor in stabilizing the ? phase by regulating the energy of deposited atoms. This approach enables the formation of ?[jls-end-space/]-W films over a wide thickness range. Power spectral density analysis of the atomic force microscopy images revealed that the ?[jls-end-space/]-W film grown at a positive substrate bias of +50 V exhibits low surface roughness along with small grain size. Additionally, we studied the spin pumping phenomena in different tungsten phases achieved through substrate bias. Ferromagnetic resonance measurements reveal an enhancement in the magnetic damping for ?[jls-end-space/]-W/Py compared to ?[jls-end-space/]-W/Py dominated film. Importantly, the use of substrate bias does not deteriorate the interface quality, underscoring its effectiveness. These findings highlight the potential of substrate bias in thin-film engineering, paving the way for its advanced utilization in spintronic applications. © 2025 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Synthesis and characterization of N-doped reduced graphene oxide for the supercapacitor application
(Springer, 2025) Moodakare, R.; Sahoo, B.; Bharadishettar, N.; Rahman, M.R.; Muhiuddin, M.; Udaya Bhat, K.
In this work, N-rGO is synthesized as a material for the electrode of supercapacitors using a single-stage hydrothermal process. Ammonia functions as a nitrogen source and a reducing agent, significantly enhancing its electrochemical properties. X-ray diffractometry (XRD), Raman spectroscopy, field emission gun scanning electron microscopy (FESEM), and FT-IR (Fourier-transform infrared spectroscopy) were employed for characterization of as-prepared N-rGO electrodes. The XRD plot evidences the successful reduction of as-received GO to as-prepared N-rGO. The FESEM micrograph displays the formation of highly porous and multi-layered N-rGO, showcasing significant structural characteristics. The nitrogen atoms are successfully incorporated into the resulting material (N-rGO) and have been verified through EDS and FT-IR spectroscopy studies. The specific capacitance of N-rGO reaches 107 Fg?1 at 0.5 Ag?1 in a 0.5 M H2SO4 aqueous electrolyte solution. The electrodes showed exceptional cyclic performance, maintaining approximately 130% capacitance after 10,000 cycles and delivering steady Coulombic efficiency. The material's porous structure and nitrogen doping create abundant active sites, facilitating electrolyte ion migration and producing exceptional capacitive performance. The electrochemical impedance spectroscopy study revealed that the N-rGO exhibited a distinctive capacitive behavior. The synthesized N-rGO offers excellent potential for an efficient energy storage application due to its simple, cost-effective, and eco-friendly approach. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.