Electrical and dielectric characteristics of molybdenum dioxide nanoparticles for high-performance electrocatalysis

As an attempt to improve the catalytic processes in different electrochemical systems, molybdenum dioxide nanoparticles were prepared using the hydrothermal method, and their electrical and dielectric properties were investigated. The nanoparticles were polycrystalline with an orthorhombic structure. AC electrical transport properties of the pressed disc were conducted over a temperature range of 303-423 K and a frequency range of 42-5 × 10⁶ Hz. The AC conductivity follows Jonscher's universal dynamic law, and it has been determined that correlated barrier hopping (CBH) is the primary conduction mechanism. The maximum barrier height ($$) was found to be 0.92 eV. The low activation energy showed that hopping conduction is the dominant mechanism of transporting current. The dielectric parameters were analyzed using both complex permittivity and complex electric modulus, with a focus on how they vary with temperature and frequency. At relatively high temperatures and low frequencies, the dielectric parameters showed a high-frequency dependence. The dielectric modulus showed that relaxation peaks move towards lower frequency when temperature increases. The dielectric relaxation activation energy, Δ $$ was determined to be 0.31 eV.