In situ hydrogenation of molybdenum oxide nanowires for enhanced supercapacitors

Abstract

In situ hydrogenation of orthorhombic molybdenum trioxide (α-MoO₃) nanowires has been achieved on a large scale by introducing alcohol during the hydrothermal synthesis for electrochemical energy storage supercapacitor devices. The hydrogenated molybdenum trioxide (H_xMoO₃) nanowires yield a specific capacitance of 168 F g⁻¹ at 0.5 A g⁻¹ and maintain 108 F g⁻¹ at 10 A g⁻¹, which is 36-fold higher than the capacitance obtained from pristine MoO₃ nanowires at the same conditions. The electrochemical devices made with H_xMoO₃ nanowires exhibit excellent cycling stability by retaining 97% of their capacitance after 3000 cycles due to an enhanced electronic conductivity and increased density of hydroxyl groups on the surface of the MoO₃ nanowires.