Synthesis and Characterization of Graphene/Binary Metal Molybdate (Graphene/Zn_1−xNi_xMoO₄) Nanocomposite for Supercapacitors

Abstract

A novel graphene/binary metal molybdate (Zn 1-x Ni x MoO 4 ) is synthesized via a facile and simple microwave synthesis route (x ¼ 0.0, 0.2, 0.4, 0.6, 0.8). Electrochemical studies are performed for all the samples to study their charge storage mechanism and frequency dependence in a three-electrode set up with 2M KOH electrolyte solution. Among the samples, Zn 0.6 Ni 0.4-MoO 4 shows better electrochemical performance which is combined with graphene so as to obtain graphene/Zn 1-x Ni x MoO 4 (x ¼ 0.4) nanocomposite. XRD and Raman analyses have confirmed formation of complexation of graphene/binary metal molybdate nanocomposite. TEM morphological profile illustrates little aggregation and interconnected layers of graphene interspersed with rice-like grains of binary metal molybdate. Graphene/Zn 1-x Ni x MoO 4 (x ¼ 0.4) exhibits good energy density and power density of 62.3 Wh kg À1 and 448.5 W kg À1 respectively with a specific capacitance of 555.5 F g À1 at 1 A g À1 . The electrode material with good cyclic stability of 85% even after 5000 charge/discharge cycles may be explored as a novel option for supercapacitors.

Construction of Lanthanum Vanadate/Functionalized Boron Nitride Nanocomposite: The Electrochemical Sensor for Monitoring of Furazolidone

“…Research into inorganic nanomaterials with persistent activity has proliferated in recent years due to novel applications with enormous interests in various technologies. Binary metal oxides (BMOs) have intensively emerged along these lines as an effective factor of functional materials for potential implementations in energy storage, biomedical, photocatalyst, energy conversion, electrochemical sensor, industrial adsorption, and so on. , BMOs exhibit abundant, exciting properties due to their excellent structural stability, diverse compositions, high theoretical capacities, suitable band gaps, crystalline phases, low charge-transfer resistance, rapid electron/ion transfer, high specific capacitance, and electronic structures. − The successes of achieving such extraordinary performances are mainly attributed to various metal compositions of ABO 4 (A = cation; B = anion). At present, rare-earth orthovanadates (RE)­VO 4 (RE = lanthanide series) arise as the most particularly exciting compound in material sciences. ,− This (RE)­VO 4 can exhibit bridging directly through oxygen atoms linkage.…”

In Situ Synthesis, Characterization, and Catalytic Performance of Polypyrrole Polymer-Incorporated Ag2MoO4Nanocomposite for Detection and Degradation of Environmental Pollutants and Pharmaceutical Drugs

“…Mo-based nanomaterials were largely studied in the field of photocatalytic pollutant degradation. − Incorporation of some precious metals to molybdenum oxides to boost the optical, catalytic, and sensing properties has conquered great attention today for their robust claim in various fields, such as photoluminescence, microwave applications, optical fibers, scintillator materials, humidity sensors, magnetic devices, catalysis, and electrochemical sensors. Recently, many metal molybdates with different morphologies and properties were reported. − Lamellar oxide of transition noble metals, mainly silver molybdate nanostructures, is bringing boundless concern among researchers due to its high-temperature friction coefficient without decomposition during melting, high electrical conductivity, surface plasmon resonance, and highly selective sensing capacity. Silver molybdate nanorods, nanowires, nanoflowers, nanocubes, nanospheres core–shell composites, nanoplates, dendrites, and other hierarchical architectures were synthesized by coprecipitation and hydrothermal methods. − In photocatalytic and electrochemical sensing performance enhancement of silver molybdate, various combinations were tried and reported. − …”

Microwave Synthesis of Zinc Ammonium Phosphate/Reduced Graphene Oxide Hybrid Composite for High Energy Density Supercapacitors

“…At higher current densities, the decrease in specific capacitance suggests that there is a lack of trapping of ions for electrochemical performance and the availability of activation sites for the electrolytic ions at the electrode–electrolyte interface is less . At lower current density, slower ion diffusion takes place, which contributes to higher ion adsorption.…”

“…The synthesis of ZAP/rGO composite is schematically represented in Figure . Graphite oxide was contrived in the lab according to the improvised method introduced by Hummer et.al as reported in the literature by Chen et al Various amounts of graphene oxide (25, 50, 75, and 100 mg) were prepared by dissolving graphite oxide in DI water at the ratio of 1 mg mL −1 and sonicating for half an hour . With this solution, 0.1 mol L −1 of zinc acetate solution mixed with DAHP solution was added and stirred to get a homogeneous solution.…”