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Fast and facile synthesis of nanomaterials is always a challenge for industrial applications in various sectors. In this work, CdMoO₄ and CdWO₄ nanoparticles are synthesized by using a fast and cost-effective microwave-assisted method. The synthesized nanoparticles are mixed with reduced graphene oxide (rGO), to form active electrode materials for supercapacitor and their electrochemical performances were studied in detail. The electrodes were prepared by simple mixtures of rGO/CdMoO₄ and rGO/CdWO₄, and electrochemical performance were measured in both, two- and three-electrode configurations. In general, both rGO/CdMoO₄ and rGO/CdWO₄ mixtures exhibit an increased specific capacitance (Cp) compared to pure rGO. Notably, the rGO/CdMoO₄ mixture shows a Cp exceeding 543 Fg⁻1 at a scan rate of 5 mVs⁻1, which represents a significant improvement over rGO alone (Cp = 225 Fg⁻1). This increase in Cp can be attributed to the higher surface area of the rGO/CdMoO₄ electrode material due to smaller size of CdMoO₄ nanoparticles and their intercalation between the rGO layers in comparison to the rGO/CdWO₄ electrode material. Furthermore, the rGO/CdMoO₄ mixture demonstrated 77% capacitance retention over 5,000 charge/discharge cycles in the two-electrode configuration. The promising electrochemical performance and rapid, low-cost synthesis suggest that these materials have great potential for further use in high efficiency energy-storage devices.

Metal–organic frameworks (MOFs) are hybrid materials that are being explored as active electrode materials in energy storage devices, such as rechargeable batteries and supercapacitors (SCs), due to their high surface area, controllable chemical composition, and periodic ordering. However, the facile and controlled synthesis of a pure MOF phase without impurities or without going through a complicated purification process (that also reduces the yield) are challenges that must be resolved for their potential industrial applications. Moreover, various oxide formations of the Ni during Ni-MOF synthesis also represent an issue that affects the purity and performance. To resolve these issues, we report the controlled synthesis of nickel-based metal–organic frameworks (NiMOFs) by optimizing different growth parameters during hydrothermal synthesis and by utilizing nickel chloride as metal salt and H2bdt as the organic ligand, in a ratio of 1:1 at 150 °C. Furthermore, the synthesis was optimized by introducing a magnetic stirring stage, and the reaction temperature varied across 100, 150, and 200 °C to achieve the optimized growth of the NiMOFs crystal. The rarely used H2bdt ligand for Ni-MOF synthesis and the introduction of the ultrasonication stage before putting it in the furnace led to the formation of a pure phase without impurities and oxide formation. The synthesized materials were further characterized by powder X-ray diffraction (XRD) technique, scanning electron microscopy (SEM), and UV–vis spectroscopy. The SEM images exhibited the formation of nano NiMOFs having a rectangular prism shape. The average size was 126.25 nm, 176.0 nm, and 268.4 nm for the samples (1:1)s synthesized at 100 °C, 150 °C, and 200 °C, respectively. The electrochemical performances were examined in a three-electrode configuration, in a wide potential window from −0.4 V to 0.55 V, and an electrolyte concentration of 2M KOH was maintained for each measurement. The charge–discharge galvanostatic measurement results in specific capacitances of 606.62 F/g, 307.33 F/g, and 287.42 F/g at a current density of 1 A/g for the synthesized materials at 100 °C, 150 °C, and 200 °C, respectively.

A controlled growth of nano/micro rods with defined morphologies are of great interest due to its special and unique properties. Here we report ethylene glycol mediated facile and controlled synthesis of ultra-long (∼100 μm) perfect hexagon shaped microrods of silver molybdate by a cost effective method of hydrothermal. The exact conditions are optimized by varying the effective parameters. The synthesis involves the mixing of different concentration of silver nitrate solution (0.025, 0.075, 0.125 M) with ammonium molybdate in the presence of 10 ml of ethylene glycol and then post hydrothermal treatment at 150 °C for 12 hrs. Only 0.075 M conc. of silver nitrate results perfect hexagons whereas the lower and higher concentrations result the formation of distorted edge shaped and longer microrods of Ag 6 Mo 10 O 33 . The magnetic measurement shows the perfect diamagnetic behavior of these mircorods. [ABSTRACT FROM AUTHOR]