Display omitted
•Bamboo-leaf activated carbon was synthesized by chemical reaction method.•Bamboo-leaf AC is analyzed using various aqueous electrolyte solutions.•AC delivers a high capacity of CP ...290F/g at 1A/g using mixed electrolytes.•Good cyclic stability around 1000 cycles with 93% capacity retention.
Activated carbon (AC) material has been prepared from bamboo-leaf carbonized under high temperature at 500 °C for 2hr. Then, the chemical reaction method was processed on carbon material to activate using KOH solvent as activating agent. XRD and FT-Raman have confirmed the crystal structure and molecule interaction of the prepared activated carbon. The morphology was characterized using FE-SEM (EDS). The novelty of activated carbon was studied by various aqueous electrolyte such as 1 M Na2SO4, 0.5 M KOH and 1 M Na2SO4 + 0.5 M KOH. The activated carbon delivers the high specific capacitance found as 290F/g at 1A/g using mixed electrolyte (1 M Na2SO4 + 0.5 M KOH). In addition, capacity retention was achieved 93% after 1000 cycles at 10A/g. Mixed electrolytes can be used as a promising electrode material for supercapacitors with high power density.
Accurate estimation of the planetary boundary layer (PBL) top is essential for air quality prediction, weather forecast, and assessment of regional and global climate models. In this article, the ...long-term climatology of seasonal, global distribution of PBL is presented by using global positioning system radio occultation (GPSRO) based payloads such as Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC), Communication/Navigation Outage Forecast System (C/NOFS), TerraSAR-X, and The Gravity Recovery and Climate Experiment (GRACE) from the year 2006–2015. We used Wavelet Covariance Transform (WCT) technique for precise PBL top identification. The derived PBL top from GPSRO data is rigorously evaluated with GPS radiosonde data over Gadanki. Significant seasonal variation is noticed in both radiosonde and GPSRO observations. Further, we compared the PBL obtained GPS RO with global radiosonde network and observed very good correlation. The number of occultations reaching down to 500 m and retrieval rate of PBL top from WCT method is very high in mid-latitudes compared to tropical latitudes. The global distribution of PBL top shows significant seasonal variation with higher during summer followed by spring, fall, and minimum in winter. In the vicinity of Inter Tropical Convergence Zone (ITCZ), the PBL top is high over eastern Pacific compared to other regions. The ERA-Interim reanalysis data underestimate the PBL top compared to GPS RO observations due to different measurement techniques. The seasonal variation of global averaged PBL top over land and ocean shows contrasting features at different latitude bands.
•A novel Metal-organic framework incorporate on NiCo2O4.•NiCo2O4 prepared by low-cost auto combustion method.•Incorporated material prepared by hydrothermal method.•NiCo2O4/MOF-5 deliver a high ...capacity of CV is 557.36F/g at 5 mV/s.•NiCo2O4/MOF-5 deliver a high capacity of CP is 357.69F/g at 1A/g.
In this article, we incorporated the Metal-organic framework (MOF-5) on NiCo2O4. First, we synthesized the Nickel cobaltite nanoparticles by combustion method. Then incorporated the MOF-5 on NiCo2O4 via the hydrothermal method. NiCo2O4/MOF-5 supported more active sites for ion transportation and storage, improving the specific capacitance of electrode materials. Prepared NiCo2O4/MOF-5 electrode exhibit a good specific capacitance of CP curves shown 357.69F/g at 1A/g and CV curves shown 557.50F/g at 5 mV/s. Thus, the as-prepared NiCo2O4/MOF-5 has a definite advantage for supercapacitor electrode materials. Which proven their promising implications in next-generation high-performance supercapacitors.
Display omitted
•A porous NiO nanocrystal was synthesised by the hydrothermal method.•NiO nanocrystal is analyzed using various aqueous electrolyte solutions.•NiO nanocrystal delivers a high capacity ...of CP is 200 F/g at 1 A/g using 1 M Na2SO4.•Good cyclic stability around 2000 cycles with capacity retention of 91% at 10 A/g.
The electrochemical performance of porous Nickel oxide nanocrystals synthesised by the hydrothermal method is discussed here. In this porous Nickel oxide, crystal structure and morphology were investigated by XRD, FT-Raman, FE-SEM and HR-TEM. The electrochemical performance of porous Nickel oxide electrode examined by various aqueous electrolytes such as 1 M Na2SO4, 0.5 M KOH and 1 M Na2SO4 + 0.5 M KOH solution. The electrode material delivers high specific capacitance found as 200 F/g at 1 A/g using a single aqueous electrolyte 1 M Na2SO4. The porous Nickel oxide nanocrystals electrode performed the long-term good cyclic stability around 2000 cycles with 91% capacity retention. Here, 1 M Na2SO4 electrolyte achieves high capacity among various electrolytes can be considered as promising electrode material for supercapacitor applications.
Metal–organic framework-derived materials are now considered potential next-generation electrode materials for supercapacitors. In this present investigation, Co3O4@MnO2 nanosheets are synthesized ...using ZIF-67, which is used as a sacrificial template through a facile hydrothermal method. The unique vertically grown nanosheets provide an effective pathway for rapidly transporting electrons and ions. As a result, the ZIF-67 derived Co3O4@MnO2-3 electrode material shows a high specific capacitance of 768 C g−1 at 1 A g−1 current density with outstanding cycling stability (86% retention after 5000 cycles) and the porous structure of the material has a good BET surface area of 160.8 m2 g−1. As a hybrid supercapacitor, Co3O4@MnO2-3//activated carbon exhibits a high specific capacitance (82.9 C g−1) and long cycle life (85.5% retention after 5000 cycles). Moreover, a high energy density of 60.17 W h kg−1 and power density of 2674.37 W kg−1 has been achieved. This attractive performance reveals that Co3O4@MnO2 nanosheets could find potential applications as an electrode material for high-performance hybrid supercapacitors.
The versatility of supercapacitors in energy storage applications has garnered much interest. Specifically, to improve the energy density by combining with the outstanding power density in higher ...energy density batteries to appear as supercapattery. Herein, for the first time, we propose a Fe2O3/α-Ni(OH)2 as an electrode for solid-state hybrid supercapattery. We construct ultrathin α-Ni(OH)2 nanosheets coated on MOF-derived Fe2O3 via the chemical bath method. The Fe2O3/α-Ni(OH)2 composite exhibits excellent electrochemical properties, including high specific capacity around 511.5 C/g (930 F/g) at 1 A/g with outstanding cycle stability (88.3%, 10,000th cycles) and the porosity of the material reveals a good surface area of 202 m2/g. The kinetic analysis reveals that Fe2O3@α-Ni(OH)2 exhibits diffusion-controlled faradaic behaviour (51% diffusion-controlled contributions). As a hybrid supercapattery, the Fe2O3@α-Ni(OH)2//Activated carbon exhibits a specific energy density of 44.51 Wh/kg and specific power density of 2465 W/kg and excellent long-term cycling stability (keep over 90.5% of the initial specific capacitance after 4000 cycles). Three prototype hybrid supercapattery devices (Fe2O3@α-Ni(OH)2(+)||Activated carbon(−)) connected in series were used to demonstrate red LED lighting. This study offers a unique approach to constructing high-performance, low-cost, and ecological green energy storage systems.
Display omitted
Four new donor–acceptor–π‐bridge–accepter–donor hole‐transporting materials (HTMs) were developed based on the 2,2′‐(4,8‐bis(octyloxy)benzo1,2‐b:4,5‐b′dithiophene (OBDT) core moiety functionalised ...with two diphenylamine‐based donor units as outlying moieties. The compounds were designed, synthesised and used in perovskite solar cells (PSCs). Each HTM was thoroughly characterized with various spectroscopic techniques, and the surface and cross‐sectional morphologies of the thin‐film topmost layer, steady‐state photoluminescence, hole mobility and PSC efficiency were estimated and correlated with a standard Spiro‐OMeTAD HTM. The stabilized photocurrent and power conversion efficiency (PCE) measurements at maximum power point tracking, and J‐Voc curves under forward, and reverse bias, were studied. The film of the methyl‐substituted derivative provided a very consistent and compact protected layer to the whole perovskite layer, which is the key to the enhancement of the Voc and fill factor (FF). The PSC device based on the methyl derivative as HTM showed a high PCE of 19.07 % (active area 0.42 cm2) which is compared to the SpiroOMeTAD control device (17.90 %; active area 0.42 cm2). Optimized devices retained about 90 % PCE for 60 days, suggesting the reported HTM framework as a promising material for PSC application, considering also that they are tuneable and can be synthesized on a large scale.
Perovskites in action: Four new donor–acceptor–π‐bridge–accepter–donor hole‐transporting materials (HTMs) were developed, based on a 2,2′‐(4,8‐bis(octyloxy)benzo1,2‐b:4,5‐b′dithiophene core moiety with two peripheral diphenylamine‐based donor units. The HTMs were characterised and used in perovskite solar cells (PSCs). A film of the methyl‐substituted derivative (structure shown below) provided a consistent and compact protected layer on the whole perovskite layer, which was key to the enhancement of the open circuit voltage and fill factor. The PSC device with this compound showed a high‐power conversion efficiency of 19.07 % (active area 0.42 cm2) which was compared to the Spiro‐OMeTAD control device (17.90 %, active area 0.42 cm2).
Metal–organic framework-derived materials are now considered potential next-generation electrode materials for supercapacitors. In this present investigation, Co 3 O 4 @MnO 2 nanosheets are ...synthesized using ZIF-67, which is used as a sacrificial template through a facile hydrothermal method. The unique vertically grown nanosheets provide an effective pathway for rapidly transporting electrons and ions. As a result, the ZIF-67 derived Co 3 O 4 @MnO 2 -3 electrode material shows a high specific capacitance of 768 C g −1 at 1 A g −1 current density with outstanding cycling stability (86% retention after 5000 cycles) and the porous structure of the material has a good BET surface area of 160.8 m 2 g −1 . As a hybrid supercapacitor, Co 3 O 4 @MnO 2 -3//activated carbon exhibits a high specific capacitance (82.9 C g −1 ) and long cycle life (85.5% retention after 5000 cycles). Moreover, a high energy density of 60.17 W h kg −1 and power density of 2674.37 W kg −1 has been achieved. This attractive performance reveals that Co 3 O 4 @MnO 2 nanosheets could find potential applications as an electrode material for high-performance hybrid supercapacitors.
Metal-organic frameworks (MOF) have recently emerged as an intriguing template for developing morphologically pre-designed metal oxide nanostructures. MOFs offer excellent control over morphology, ...extremely high porosity and large surface area, which is highly beneficial for supercapacitor electrode applications. We report the synthesis of bimetallic MOF-derived Nickel Manganese oxide for an electrode in supercapacitor by an efficient solvothermal and subsequent calcination route. The physical characterization was carried out by X-ray diffraction (XRD), Scanning electron microscope (SEM), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Thermogravimetric analysis (TGA) and Bruner-Emmert-Teller (BET). We performed the cyclic voltammetry (CV), chronopotentiometry (CP), and electronic impedance spectroscopy (EIS) test in a 1 M KOH electrolyte to examine the electrochemical characteristics of the prepared samples. NiMn2O4 electrode material revealed high specific capacitance of 1387 F/g at 1 A/g current density and prominent cycle life (80% capacitance retention after 6500 cycles) and the porous structure of the material has a good BET surface area of 84.3 m2/g. Further, we performed spin-polarized ab-initio density functional theory calculations to study the structural, electronic, and magnetic properties of the spinel NiMn2O4 structure. Our calculated results are close to the experimentally determined structural parameters, and the enthalpy of formation confirms the thermodynamical stability of the spinel structure with ΔHF = −1.6 eV/atom. The orbital projected electronic structure is further investigated to understand the contribution of elements near the Fermi region, which paves the way for further understanding of the distribution of electrons at a particular energy interval of our system. The present findings will aid in fabricating the bimetallic MOF-derived metal oxide nanostructures for the next-generation supercapacitors.
Display omitted
Due to their vast surface area and superior porosity structure, metal-organic frameworks (MOFs) derived materials have recently presented a significant promise for better lithium-ion batteries ...(LIBs). Herein, we synthesised MOF-derived porous NiCo2O4 nanofile arrays from a simple solvothermal technique followed by calcination at 450 °C. The prepared sample was characterized by X-ray diffraction, thermogravimetric, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller. The acquired nanofile array morphology achieved a large specific surface area of 189 m2/g can shorten the Li ions (Li+) transport and enhance the electrochemical performance. As expected, the prepared electrode reveals a discharge-specific capacity of around 1120 mAh/g at a 0.1 C rate. At 2 C rate, the electrode's specific capacity can still reach 210 mAh/g after 100 cycles. The pseudocapacitive nature of NiCo2O4 was determined by kinetic analysis, revealing the diffusion-controlled faradaic behaviour. Our prepared electrode material is considered an attractive option for the anode material in rechargeable Li-ion batteries because it has been proven to have a relatively good specific capacity and cycling stability.
Display omitted
•The Porous NiCo2O4 nanofile arrays is synthesised by a solvothermal process.•The electrode exhibits a good specific capacity of 1120 mAh/g at 0.1 C rate.•Kinetic analysis reveals the dominant diffusion-controlled process.•The diffusion can be enhanced by surface area, which benefits Li+ transport.
