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The synthesis of bismuth based materials with porous structures for supercapacitor application has drawn much attention due to their high specific surface area and easy access of electrolytes with the electrode surface through their hierarchical pores. In this present report, we synthesized a three dimensional (3D) BiOCOOH micro flowers by a solvothermal approach and applied to supercapacitor applications. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy results confirmed that the formation of porous BiOCOOH flowers. When BiOCOOH was used as electrode material for supercapacitors it exhibits a maximum specific capacitance value of 312 F g−1 at current density of 1 Ag−1. Additionally, the BiOCOOH flowers retained 52% of its initial specific capacity after 5000 charge–discharge cycles indicating an excellent cyclic stability. This improvement in the cycle stability of the BiOCOOH is ascribed to high surface area and enhanced ion transport through the pores of the BiOCOOH flowers. This high specific capacitance and excellent cyclic stability of the porous BiOCOOH flowers prove to be a promising candidate for supercapacitor application. [ABSTRACT FROM AUTHOR]

ZnO nanotips structure fabrication was undertaken through controlled growth by chemical vapor deposition (CVD) method. Substrate position and deposition time role was investigated systematically by controlling the parameters such as temperature, flow rate, and growth pressure. The obtained result showed that ZnO nanorods undergo a sharp regrowth process with increase in ZnO vapor availability in the CVD reactor. The surface morphology and structural properties were investigated by using field-emission scanning electron microscopy and X-ray diffraction (XRD) techniques. The grown nanostructures were used for gas sensor fabrication to detect and to study the sensitivity effects of H2 and CO. [ABSTRACT FROM AUTHOR]

Nickel-doped magnesium oxide (Ni-MgO) nanopowders were successfully synthesized by employing a simple sol-gel process by adopting different surfactants such as Hexamine, CTAB and PEG-400. XRD results clearly revealed the formation of face centered cubic structure. The characteristic PL peaks observed at 401, 490 and 552 nm are owing to charge transfer characteristic in surface state of the obtained product. The characteristic IR peaks observed at 445 and 854 cm could be attributed to Mg-O stretching vibration and the peak appeared at 1036 cm belongs to Mg-O vibrations modes. Scanning electron microscopy (SEM) results clearly revealed the uniform distribution of thin nanolayer morphology in different direction for Ni-MgO (CTAB) product, the mixture of nanolayer and nanoparticle configurations for Ni-MgO (Hexamine) product and more agglomerated particle formation for Ni-MgO (PEG-400) product. The electrochemical studies were carried out to estimate the specific capacitance of Ni-MgO (CTAB) product at low scan rate 10 mV/s which showed an excellent value of 360.5 F/g. The GCD studies for synthesized Ni-MgO (CTAB) nanolayer morphology have superior specific capacitance of 96 F/g at 1 A/g with the excellent specific capacitance. The materials stability for 5000 charging and discharging cycles retains 68% of the specific capacitance 83 F/g at current density of 5 A/g. [ABSTRACT FROM AUTHOR]

The monodispersed CuFe 2 O 4 nanoparticles were synthesized and optimized by employing solvothermal method and were studied by employing X-ray diffraction (XRD) method. The obtained products have tetragonal crystalline cubic-spinel type structure belonging to I 4 1 / a m d space group. The Raman and infrared studies analyzed the different vibration and starching modes of metal-oxide and the pure phase of the obtained CuFe 2 O 4 nanoparticles. The morphology nature of monodispersive CuFe 2 O 4 nanoparticles can be easily identified from field-emission scanning electron microscopy images, and the role of different molarities of KOH at 1, 5, and 10 M (BS1, BS2, BS3) can be clearly observed. The X-ray Photon spectroscopy (XPS) studies the oxidation states of the Cu-2p, Fe-2p and O-1s in CuFe 2 O 4 nanoparticles, which validates the XRD data and supports the crystalline formation. The specific capacitance of BS1 is 189.2 F/g at current density 0.5 A/g. As the current density increases, the diffusing rate of electrolyte ions into the electrodes will reduce, which is reflected in the specific capacitance of CuFe 2 O 4 nanoparticles. The cyclic stability of CuFe 2 O 4 nanoparticles (BS1) exhibits 84% retention after 1000 cycles of galvanostatic charging and discharging studies and the pattern of curve remains the same, which indicates very good coulomb efficiency after long cycles. • The specific capacitance of CuFe 2 O 4 is 189.2 F/g at current density 0.5 A/g. • CuFe 2 O 4 exhibits 84% retention after 1000 cycle's. • It exhibits very good coulomb efficiency after long cycles. [ABSTRACT FROM AUTHOR]

Ag-doped cobalt oxide (Co 3 O 4 ) nanorods were successfully synthesized using hydrothermal route at 90, 120, 150, and 180 °C. The face-centered cubic structure of Co 3 O 4 was confirmed through X-ray diffraction pattern. A well-defined Raman active mode of vibrations (E g + F 2g + A 1g ) revealed the cubic Co 3 O 4 formation. The morphology of Ag-doped Co 3 O 4 nanorods was revealed from scanning electron microscopy images. High specific capacitance of 584 F/g at scan rate of 5 mV/s was obtained for the product synthesized at 150 °C. The improved oxygen evolution reaction (OER) for the synthesized materials was observed using linear sweep voltammogram, electrochemical impedance spectroscopy, and chronoamperometry. The obtained Ag-Co 3 O 4 nanomaterials have more possibility to be adapted as OER catalyst for water splitting application. [ABSTRACT FROM AUTHOR]

[Display omitted] • Kaolin/g-C 3 N 4 /WO 3 nanocomposite has been synthesised and characterised. • The ternary nanocomposite has been characterized by various analytical techniques. • The specific surface area of the nanocomposite is obtained using BET isotherm. • The energy storage application of the nanocomposite has been studied using electrochemical, impedance and GCD studies. In order to investigate the synergistic potential of a new nanocomposite for improved energy storage applications, this work combines graphitic carbon nitride (g-C 3 N 4), vanadium pentoxide (V 2 O 5) and kaolin. Kaolin functions as a structural matrix, offering stability and support for the integration of g-C 3 N 4 and V 2 O 5 nanoparticles. It is well-known for its wide availability and thermal characteristics. A variety of analytical methods, such as electrochemical analysis, scanning electron microscopy and X-ray diffraction, are used to characterise the synthesised nanocomposite. The specific capacitance and cycling stability of the nanocomposite's electrochemical performance are rigorously assessed. Key issues in efficiency, stability and cost-effectiveness are addressed by an optimised material for advanced energy storage systems, which is the result of the synergistic effects coming from the unique features of each component. With a superior cyclic stability and capacitance retention of 77.7 % even after 2000 cycles, the composite material exhibits a higher specific capacitance value of 415 Fg−1 at 5 mVs−1. This work is a major step towards the creation of novel nanocomposites for high-performing, environmentally friendly energy storage systems. [ABSTRACT FROM AUTHOR]