Room-temperature solution-processed sharp-edged nanoshapes of molybdenum oxide for supercapacitor and electrocatalysis applications

Abstract

We introduce a simple room-temperature (25–27 °C) solution process-inspired approach for obtaining sharp-edged nanoshapes like nanocubes, nanorods and nanoparticles of molybdenum oxide (MoO3) on a stainless-steel conducting substrate for supercapacitor and electrocatalysis applications. The nanoshape of MoO3 has strikingly been changed from nanocubes to nanopaticles dependig on HCl concentration. The MoO3 electrodes of different morphologies are systematically characterized by various characterization techniques for confirming phase, structure, and surface elementals. The electrochemical studies exhibit significant enhancement in specific capacitance and oxygen evolution reaction (OER) activity for MoO3 nanorod-based electrode. The specific capacitance of 2561.53 F g−1 for MoO3 nanorods is much higher than 608.20 F g−1 and 400.28 F g−1 for nanocubes and nanoparticles, respectively. Besides, with the 98.59% capacitance retention up to 2000 cycles, the electrode consisting nanorods is found to be highly stable. In the commercial point of view, the as-fabricated MoO3//MoO3 symmetric device adduces excellent energy/power density (69.06 Wh kg−1/1336.63 W Kg−1) at current density of 1 A g−1. The laboratory panel, Center for Nanomaterials & Energy Devices, containing nearly 42 LEDs has been ignited with full intensity using MoO3//MoO3 symmetric device as the practical demonstration of electrode material. From supercapacitor study, the MoO3 nanorod-based electrode endows excellent OER activity (overpotential of 246 mV; Tafel slope of 36 mV dec-1). In both cases, the MoO3 nanorod-based electrode produces excellent chemical and cyclic stability. Overall electrochemical results demonstrate that the MoO3 nanorod-based electrode would be excellent electrode material for supercapacitor as well as OER applications. The proposed room-temperature solution synthesis process is valuable and well effective in view of trouble-free, cost-effective, and scalability for commercial benefits.