Enhanced supercapacitor and photocatalytic performance of Zn doped nickel molybdate nanoparticles
摘要
Zinc doped nickel molybdate (Zn-NiMoO₄) nanoparticles were synthesized via a facile hydrothermal method at a low reaction temperature of 160 °C. The resulting material was comprehensively analyzed to assess its structural, optical, and electrochemical properties. X-ray diffraction (XRD) analysis confirmed the prepared molybdates were monoclinic crystal structure with average crystallite size increased from 26 to 33 nm. Fourier transform infrared spectroscopy (FTIR) detected characteristic metal-oxide stretching vibrations in the range of 400 to 800 cm− 1. Field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM) analyses confirmed the formation of nanoparticles with a distinct cubic morphology. X-ray photoelectron spectroscopy (XPS) analysis identified the oxidation states and confirmed the elemental composition, including the presence of Zn2+, Ni2+, and Mo6+. Nitrogen adsorption-desorption measurements indicated a mesoporous structure with a high specific surface area of 112 m²/g. Furthermore, the optical band gap decreased from 2.90 eV for pure NiMoO4 to 2.75 eV with 2% Zn doping. The photocatalytic efficiency of Methylene Blue (MB) was improved by doping of Zn ions into NiMoO₄. Theelectrochemical performance was evaluated in a three-electrode setup with a 2 M KOH aqueous electrolyte. The material demonstrated good pseudocapacitive behavior, achieving a high specific capacitance of 826 F/g at low scan rate 5 mV/s.