The potential of hydrothermally synthesized MoO3 and Cr doped MoO3 nanoparticles for electrochemical energy storage applications

Molybdenum trioxide (MoO 3 ) based electrode materials have generated interest for electrochemical energy storage application due to their exceptional optical and chemical properties. However, MoO 3 suffers from some drawbacks such as weak electrical conductivity and instability which have necessitated new and innovative approaches to overcome these challenges. In this work, we doped MoO 3 with chromium (Cr) with the aim of enhancing its conductivity and further studied the effect of hydrothermal treatment time on its physicochemical and electrochemical properties. The x-ray diffraction results indicate that the materials exhibited an orthorhombic crystal structure. The electrochemical results show that the Cr doped MoO 3 obtained after 12 h of hydrothermal treatment (Cr@MoO 3 -12h) gave the highest specific capacitance of 465 Fg −1 , much higher than the other chromium doped MoO 3 and the undoped MoO 3 nanoparticles at all the hydrothermal treatment times considered. The Cr@MoO 3 -12h electrode also showed the highest stability retaining almost 89% of its initial specific capacitance over charge-discharge cycles 5000 cycles at 1 A g −1 . This suggests that chromium doping and maximizing the hydrothermal treatment duration improved the electrochemical performance of the molybdenum trioxide nanoparticles.