Self-assembled cotton-like copper–molybdenum sulfide and phosphide as a bifunctional electrode for green energy storage and production

Abstract

As the world's energy needs grow and environmental concerns intensify, there is an increasing need for research into developing new materials that may be used in energy production and storage. Herein, we developed copper-molybdenum (Cu–Mo) sulfide and phosphide-based cotton-like nanoarchitectures via hydrothermal strategy and they were characterized using various analytical techniques. The prepared sulfide and phosphide-based materials showed HER overpotentials of 207 mV and 147 mV, respectively, as well as Tafel slope values of 118 mV/dec and 109 mV/dec at 10 mA/cm2. While OER at the same current density showed 270 mV and 213 mV overpotentials with 82 mV/dec and 48 mV/dec Tafel slope, respectively. In addition, the prepared sulfide and phosphide-based materials showed significant performance towards supercapacitors, displaying specific capacitances of 3.5 and 5.2 F/cm2 at 3 mA/cm2, and retaining their specific capacitances by 86.9 and 69.4%, respectively, after 4,000 cycles with 100% Coulombic efficiency. These materials have the potential to be employed for energy production and storage because of their excellent electrochemical characteristics and bifunctional performance.