查看文章

Supercapacitors are a class of energy storage devices which rely on surface reactions in an electrochemical environment to store charges. These surface reactions involve forming a double layer of immovable electrostatic charges that is separated from the electrode by a few Å. Else it can also involve redox reactions at the electrode surface which is usually initiated by ions from the electrolyte. Supercapacitors takes small amount of time for their charging and discharging process, demonstrates high cyclic lifetime and has a high rate capacity. Supercapacitors can achieve a high power density which is ideally suited for applications where short burst of power is required. High electrode surface area can boost the capacitance, while use of neutral aqueous based, organic based and ionic liquid based electrolytes have shown to enhance the voltage capability of the supercapacitor which can drive up its energy density.

Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER) are constituent reaction of electrochemical splitting of water (H2O) molecule in the presence of a catalyst. These reactions form part of a promising water based energy cycle which can happen in an acidic or an alkaline environment. The role of electrocatalyst is vital in determining the potential and kinetics of these reactions. Electrocatalysts having metal ions high redox activity, high surface area and suitable binding energies of reaction intermediaries, and low toxicity are highly sought after for these aforementioned reactions.