The h-WO3@Ti electrode serves as the WE in the construction of the CAPode device, with NC@Ti functioning as the CE. The performance of the CAPode is initially investigated using the CV technique at a constant scan rate of 20 mV s -1 while varying the voltage window (Figure ). Basically, the CAPode concept is fundamentally based on an asymmetric current response around 0 V, mimicking a semiconductor diode. It exhibits a high current response under specific polarization conditions, referred to as "open/chargeable" polarization (in this case, "negative" voltage), and a low current response known as "blocked/unchargeable" polarization (in this case "positive" voltage).