Influence of substrate temperature on the structural, morphological, and electrochemical properties of α-MoO3 thin films for supercapacitor electrodes
摘要
Thin films of nanostructured molybdenum trioxide (α-MoO3) were synthesized by varying the substrate temperature from 250 to 350 °C at the interval of 25 °C to assess the impact on their structural, morphological, optical, electrical, and electrochemical properties. X-ray diffraction patterns confirmed that the resulting α-MoO3 films were polycrystalline and adopted an orthorhombic phase. The films showed improved crystallinity at the optimum substrate temperature of 300 °C. The optical bandgap values were found to be in the range of 3.03–3.25 eV, and the activation energies spanned from 0.04 to 0.30 eV. Electrochemical testing indicated that the α-MoO3 film deposited at 300 °C exhibited the best supercapacitive behavior, delivering a specific capacitance of 212 Fg−1 in a 1 M Na2SO4 electrolyte at a scan rate of 5 mVs−1, and 234 Fg−1 at a current density of 0.5 Ag−1. These findings emphasize the importance of substrate temperature in tuning the functional properties of α-MoO3 thin films for advanced supercapacitor applications.