Department Of Physics
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Item NiO and magnetic CuFe2O4-based composite electrocatalyst for enhanced oxygen evolution reaction(Springer Science and Business Media Deutschland GmbH, 2023-09-13T00:00:00) BaQais, Amal; Shariq, Mohammad; Almutib, Eman; Al-Qasmi, Noha; Azooz, R.E.; Ali, Syed Kashif; Hassan, K.F.; Iqbal, MuzahirThe biggest concerns confronting the modern world are the depletion of nonrenewable energy sources and rising global temperatures. The use of O2 as an alternative energy source offers a potential answer to these problems. Low-cost electrocatalysts are growing approach for electrocatalytic water splitting, such as oxygen evolution reaction (OER). Oxygen evolution reactions are tremendously well-catalyzed by inexpensive transition metal oxide-based nanostructures. Here, we present a new composite NiO/CuFe2O4 nanostructure and further investigate its potential for electrocatalytic OER applications. Microscopic and spectroscopic methods such as FE-SEM, XRD, XPS, and FTIR were utilized to explore the morphology and structural characteristics of the electrocatalyst. The composite NiO/CuFe2O4 catalyst demonstrates excellent electrochemical OER accomplishment with the overpotential of 297�mV for an alkaline medium to acquire the current density of 10�mA/cm2 and a low Tafel slope of 63�mV/dec?1 to confirm the faster reaction of the composite catalyst. The synergism between the metal ions Ni, Cu, and Fe makes the composite catalyst more efficient in its catalytic activity so; the as-prepared structure demonstrates higher electrocatalytic OER execution with cyclic stability and durability than its pristine constituents. The results show that the NiO/CuFe2O4 composite has the potential to act as an electrocatalyst for the splitting of water. � 2023, The Author(s), under exclusive licence to Societ� Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature.Item Microwave-Induced Rapid Synthesis of MoS2@Cellulose Composites as an Efficient Electrode Material for Quasi-Solid-State Supercapacitor Application(John Wiley and Sons Inc, 2023-03-11T00:00:00) Iqbal, Muzahir; Saykar, Nilesh G.; Mahapatra, Santosh kumarTransition-metal dichalcogenides (TMDs) are highly desired for energy-storage devices due to their intrinsic layered structure, huge surface area, and the large number of active sites. However, the TMDs fail to reach their potential due to restacking of 2D layered structures that remains a major technological hurdle. Herein, MoS2 nanosheets and cellulose fiber binary composite (MoS2@Cellulose) prepared by the microwave-assisted technique are demonstrated as an electrode material for supercapacitor application. The prepared material are tested in symmetric and asymmetric all solid-state device assemblies. It is found that the quasi-solid-state symmetric and quasi-solid-state asymmetric supercapacitors exhibited remarkably higher specific capacitance of ?294 and ?177 F g?1 at a current density of 1 A g?1, respectively, than their counterpart. Furthermore, the symmetric and asymmetric devices deliver excellent energy densities of ?40.84 and ?42.67 Wh kg?1 while maintaining the power density of 400 and 791.81 W kg?1, respectively, and outstanding cyclic stability. The cellulose entanglement causes a reduction in the aggregation and restacking of MoS2, which may improve the electrochemical performance of the supercapacitor. Herein this research, a pathway is provided to create an efficient energy-storage system using 2D materials with sustainable cellulose. � 2023 Wiley-VCH GmbH.Item Synergistic Effect of Crystallization Control and Defect Passivation Induced by a Multifunctional Primidone Additive for High-Performance Perovskite Solar Cells(American Chemical Society, 2022-12-22T00:00:00) Saykar, Nilesh G.; Iqbal, Muzahir; Ray, Asim K.; Mahapatra, Santosh K.The ionic nature of organic-inorganic metal halide perovskites endows intrinsic defects at the surface of the polycrystalline films. Simultaneous defect passivation during the growth of perovskite films could inhibit defect formation to a great extent. Herein, the anticonvulsant drug primidone (PRM) is demonstrated as a novel additive to control the crystallization and defect passivation of perovskites. The spectroscopic measurements support theoretical predictions showing the strong interaction between active functional groups and PbI2. An amount of PRM is tuned to obtain the perfect perovskite films with improved grain size and crystallinity than their control counterparts. Efficient PbI antisite defect passivation suppresses the non-radiative recombinations, resulting in higher luminance intensity and significantly longer charge carrier lifetimes. The PRM-modified perovskite solar cells (PSCs) show a power conversion efficiency (PCE) of 18.73%, much higher than that of control PSCs (16.62%). The ambient stability of PRM-modified PSCs is meritoriously increased compared to control PSCs. The PRM-modified PSCs show stability retention of up to 85% of the initial PCE after 1000 h, while control PSCs retain only 25% of the initial PCE after 550 h. The multifunctional defect passivation approach with the PRM additive shows the effective way for the efficiency and stability improvement of PSCs. � 2022 American Chemical Society.Item Dual-Functional 3-Acetyl-2,5-dimethylthiophene Additive-Assisted Crystallization Control and Trap State Passivation for High-Performance Perovskite Solar Cells(American Chemical Society, 2022-11-25T00:00:00) Saykar, Nilesh G; Iqbal, Muzahir; Pawar, Mahendra; Chavan, Kashinath T; Mahapatra, Santosh KDefect-mediated charge recombination and successive degradation mainly lag the performance of perovskite solar cells (PSCs). Insufficiency or evaporation of organic cations leaves behind the undercoordinated Pb2+ions, which act as severe charge recombination centers. Herein, theoretical and experimental insights into crystallization control and defect passivation of MAPbI3perovskite by the dual-functional 3-acetyl-2,5-dimethylthiophene (ADT) molecule are presented. Density functional theory calculations show that both functional groups of ADT possessing different interaction energies could interact with PbI2. The carbonyl group in ADT shows the dominant interaction with Pb2+forming an intermediate product that might decrease the crystallization rate. Further, the coordinate bonding between ADT and uncoordinated Pb2+ions in perovskite leads to defect passivation. The 0.6% ADT-modified PSCs possess an average power conversion efficiency (PCE) of 18.22 � 0.80% and the highest PCE of 19.03%, whereas the pristine PSCs exhibit an average PCE of 16.23 � 1.32% and the highest PCE of 17.47%. Furthermore, the modified PSCs maintain 80% of the initial PCE up to 650 h during storage at ambient conditions (RH = 35 � 5%). The present study shows that the simultaneous crystalization control and defect passivation achieved via an ADT additive engineering approach could be an efficient strategy to enhance the PCE and stability of PSCs. � 2022 American Chemical Society. All rights reserved.Item Mesoporous carbon/titanium dioxide composite as an electrode for symmetric/asymmetric solid?state supercapacitors(Elsevier Ltd, 2022-08-27T00:00:00) Arya, Anil; Iqbal, Muzahir; Tanwar, Shweta; Sharma, Annu; Sharma, A.L.; Kumar, VijayThis paper reports the successful synthesis of mesoporous carbon/titanium dioxide (MC/TiO2) composite electrodes via the hydrothermal method for supercapacitor (SC) applications. The morphology and structural properties of MC/TiO2 composites were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectra (FTIR). The electrochemical properties were recorded by cyclic voltammetry (CV) and galvanostatic charge/discharge (GCD) with an electrolyte (6 M KOH) in symmetric/asymmetric configuration. The specific capacitance (Cs) evaluated by CV is about 280F/g for composite electrode (95 % capacitance retention after 1000 cycles) and pristine has 150F/g @ 10 mV/s. Enhancement in capacitance is owing to faster charge dynamics within electrode material. The fabricated asymmetric device demonstrates high energy density (30.31 Wh/kg), than the symmetric configuration (?27 Wh/kg). Finally, both symmetric/asymmetric supercapacitors have illuminated a red LED, and strengthens the candidature of composite electrode for energy storage technology. � 2022 Elsevier B.V.Item One-step hydrothermal synthesis of MoS2 nano-flowers CoS2 square composites electrode materials for supercapacitor application(Elsevier Ltd, 2022-07-27T00:00:00) Iqbal, Muzahir; Saykar, Nilesh G.; Kumar Mahanta, Alok; Mahapatra, S.K.Developing efficient materials for generating and storing renewable energy is now a pressing test for future energy demand. The advent of (2D) two-dimensional materials has attracted much research interest as electrode materials for supercapacitors due to their intriguing mechanical and electrochemical properties. This report used a facile one-step hydrothermal process to synthesize MoS2@CoS2 Composite as electrode materials for supercapacitors with good energy storage performance and explore energy generation and storage applications. The structure and morphology were investigated by X-ray diffraction pattern, field emission scanning electron microscope consisting of square-shaped CoS2 and flower-like MoS2, and characterization; meanwhile, their electrochemical properties were evaluated by CV, GCD, and EIS measurements. The electrochemical performance of symmetric MoS2@CoS2 binary Composite was examined in 1 M H2SO4 in a two-electrode assembly. The as-prepared MoS2@CoS2 electrode exhibited a specific capacitance of 199F/g at a current density of 2A/g, while its counterpart MoS2 electrode exhibited only 127F/g at 2 A/g current density. The MoS2@CoS2 composite attains specific energy and power densities of 27.74 WhKg?1 and 494.46 Wkg?1, respectively, due to the unique morphology of the MoS2-flowery shape and CoS2 square. CoS2 squares effectively prevent the agglomeration and restacking of MoS2 sheets, facilitating smother ion dynamics. Technological demonstration of MoS2@CoS2 cell is presented by illuminating commercially available light-emitting diode for more than 3 min. � 2022Item Synergistically modified WS2@PANI binary nanocomposite-based all-solid-state symmetric supercapacitor with high energy density(Royal Society of Chemistry, 2022-03-09T00:00:00) Iqbal, Muzahir; Saykar, Nilesh G.; Alegaonkar, Prashant S.; Mahapatra, Santosh K.The rapid development of intelligent, wearable, compact electronic equipment has triggered the need for durable, flexible, and lightweight portable energy storage devices. Nanomaterials that are capable of delivering the high specific power density and commensurate energy density are potential candidate for realizing such devices. Herein, we report the facile synthesis of a binary nanocomposite WS2@PANI by utilizing hydrothermal and physical blending techniques to assess it as an electrode material for high-performance supercapacitors. The nanocomposite electrode delivered specific capacitance >335 F g?1 @ 10 mV s?1 (two-electrode), achieving energy and power densities of ?80 W h kg?1 and ?800 W kg?1, respectively, with capacitance retention of 83% even after 5000 charge-discharge cycles @ 10 A g?1, all of which are superior to the WS2 electrode. Dunns model quantifies capacitive and intercalative contributions that showed the cumulative effect of both to realize a robust, cost-effective, and energy-efficient device. The strategically incorporated PANI broadened the electrochemical window and the device's overall performance, resulting in high specific energy density. We demonstrated that our all-solid-state symmetric supercapacitor could be used to illuminate a light-emitting diode and drive a rotary motor. We believe that our WS2@PANI binary nanocomposite will be a potential candidate for energy storage devices. � 2022 The Royal Society of ChemistryItem High-performance supercapacitor based on MoS2@TiO2 composite for wide range temperature application(Elsevier Ltd, 2021-06-07T00:00:00) Iqbal, Muzahir; Saykar, Nilesh G.; Arya, Anil; Banerjee, Indrani; Alegaonkar, Prashant S.; Mahapatra, S.K.Transition metal sulphide and their composites gain attention as electrode material in energy storage devices due to their superior properties like excellent conductivity, high surface area, and porosity. We report an evaluation of the electrochemical performance of MoS2@TiO2 binary composite in symmetric supercapacitor assembly at different temperatures. A facile hydrothermal technique is used to prepare MoS2@TiO2 binary composite. Structural and morphological analysis reveals that highly crystalline composite comprising MoS2 assembled in flower-like flake configuration, whereas, TiO2 in nanorods form are prepared. Among all three electrodes, MoS2@15%TiO2 demonstrates maximum specific capacitance 210 F/g at 10 mV/s with excellent cycling stability (98%, 2000 cycles) at ambient temperature. It may be concluded that the mono-phased, mesoporous structure is a key feature behind the improved performance over the other electrodes. Further, improvement in charge-discharge characteristics has been observed by a factor of 200% at 60 �C attributing to low activation energy and faster ion dynamics at elevated temperatures. The impedance spectroscopic analysis reveals a significant reduction in interfacial impedances that leads to a superior capacitance effect compounded with favourable electrolytic charge dynamics. The highest energy density is reported to be 21 Wh/kg with a power density of 1300 W/kg in symmetric configuration. Synergistic effect of the binary system along with unique surface morphology and charge storage followed by intercalation and capacitive mechanism results in enhanced performance of supercapacitor with MoS2@15%TiO2. Thus, binary MoS2@TiO2 composite seems to be an exceptional candidate for the energy storage device operating at a wide temperature range (25�60 �C). � 2021 Elsevier B.V.