Tuning the electrochemical properties of nanostructured CoMoO4 and NiMoO4 via a facile sulfurization process for overall water splitting and supercapacitors

In contemporary society, there are many different ways that energy is used in daily life. From applications that require a high energy density to long-term storage in a stable manner, the requirements for energy usage are diverse. Therefore, the greater the number of uses a designed material exhibits, the more practical it may be for wide-scale manufacture. Two areas of particular interest for energy applications are fuel cells (to generate energy) and supercapacitors (to store energy). To provide cheaper and more durable alternatives for energy storage, electrodes containing CoMoO 4 , NiMoO 4 , CoMoS 4 , and NiMoS 4 were synthesized. The electrodes were synthesized through a hydrothermal method using Ni-foam as the substrate then tested as electrocatalysts for water splitting and electrodes for supercapacitor. As an electrocatalyst for hydrogen evolution reaction , NiMoS 4 displayed the lowest overpotential of 148 mV with a Tafel slope of 159 mV/dec. On the other hand, CoMoS 4 showed the lowest overpotential of 189 mV with a Tafel slope of 78 mV/dec among all four samples for oxygen evolution reactions . In terms of energy storage, the CoMoO 4 had the highest specific capacitance of 2652 F/g at a current density of 0.5 A/g with an averaged charge retention of 91% and a Coulombic efficiency of 99% after 10,000 cycles. • Nanostructured CoMoO 4 and NiMoO 4 were synthesized using a facile solvothermal method. • CoMoO 4 and NiMoO 4 were used for supercapacitor and electrochemical water splitting applications. • NiMoS 4 displayed the lowest overpotential of 148 mV with a Tafel slope of 159 mV/dec for the HER process. • A specific capacitance of 2652 F/g at 0.5 A/g with excellent cyclic stability was observed.