In situ hydrogenation of molybdenum oxide nanowires for enhanced supercapacitors

Abstract

In situ hydrogenation of orthorhombic molybdenum trioxide (a-MoO 3 ) 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 x MoO 3 ) nanowires yield a specific capacitance of 168 F g À1 at 0.5 A g À1 and maintain 108 F g À1 at 10 A g À1 , which is 36-fold higher than the capacitance obtained from pristine MoO 3 nanowires at the same conditions. The electrochemical devices made with H x MoO 3 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 MoO 3 nanowires.

Hydrothermal approached 1-D molybdenum oxide nanostructures for high-performance supercapacitor application

“…Growth mechanism involved in the formation of molybdenum oxide nanorods oxide nanorods is significantly higher than the values previously reported [18,34,36,42]. This significant amount of electrochemical performance can be attributed to the nanorods structure, which plays an essential role in the accessibility of electrolyte ions (Na + ) to the MoO 3 active material.…”

“…The peak at 534 cm −1 is attributed to the vibrations of the Mo-O-Mo bond of oxygen atoms of molybdenum oxide. The peaks at 870 cm −1 and 988 cm −1 are associated with Mo-O-Mo bond symmetric vibrations and characteristic stretching vibration of Mo=O bond, which is the essential characteristic of the layered orthorhombic MoO 3 phase [36]. Peaks at 1630 cm −1 and 3448 cm −1 attributes to stretching and bending vibrations of OH groups in water molecules.…”

“…Wang et al synthesized α-MoO 3 nanorods through the hydrothermal method and observed that annealed α-MoO 3 nanorods demonstrated excellent specific capacitance than compared to hydrothermally obtain ones [35]. Shakir et al reported the preparation of orthorhombic molybdenum trioxide nanowires using a hydrothermal method which yielded a specific capacitance of 168 F g −1 at 0.5 Ag −1 current density and 97% cyclic retention in 1M H 2 SO 4 electrolyte solution [36].…”

A general method to fabricate MoO3/C composites and porous C for asymmetric solid-state supercapacitors

“…11 Shakir et al synthesized hydrogenated molybdenum trioxide (H x MoO 3 ) nanowires that yielded a specic capacitance of 168 F g À1 at 0.5 A g À1 , with excellent capacitance retention of 97% aer 3000 cycles. 12 Wen et al synthesized polypyrrole@MoO 3 / reductive graphite oxide nanocomposites which demonstrate favorable cycling behavior at a current density of 0.5 A g À1 ; the capacity loss was only 12% aer 600 cycles. 13 However, the energy density of MoO 3 -based electrodes is hindered by their narrow operation potential window, which is only about À1 to 0 V vs. Ag/AgCl in Na 2 SO 4 aqueous solution due to decomposition of the aqueous electrolyte.…”

High Energy Density Ternary Composite Electrode Material Based on Polyaniline (PANI), Molybdenum trioxide (MoO3) and Graphene Nanoplatelets (GNP) Prepared by Sono-Chemical Method and Their Synergistic Contributions in Superior Supercapacitive Performance

“…The CV plots for PMG composite contain these peaks characterizing PANI along with the redox peaks at around 0.13 V-0.6 V demonstrating different redox alteration of Mo species [ Fig. 13c] [46,47]. It is also evident that higher scan rate not only causes the elevation in intensities of the redox peaks but also increases their separation specifying the increased overpotentials [28].…”