Active Porous Electrodes Prepared by Ultrasonic‐bath and their Application in Glucose/O2 Electrochemical Reactions

Most of the practical applications in electrocatalysis require porous electrodes, built by dispersing the nanoparticles (NPs) on a gas diffusion layer, as carbon paper (CP). The lack of correlation between classic measurements in clean, controlled surfaces and thin films with those of porous electrodes, used in practical application, is largely neglected. Since catalysis depends on the area available, it is clear that the distribution of the NPs on the porous material is pivotal to the efficiency of the catalyst. Here we show a low‐cost method to disperse NPs on CP assisted in ultrasonic bath. Such method improves the Pt/C NPs distribution over the CP compared to the immersion method. As proof‐of‐concept, we show an increase in output current by using Pt/C/CP for 10 mM glucose electrooxidation and O₂ eletroreduction in buffered solution at 37 °C, which is ascribed to the increase in collision factor. Furthermore, the cathodic reaction is facilitated compared to electrodes prepared by immersion, yielding an unprecedented open circuit voltage of 800 mV for the coupled reaction. The glucose/oxygen reaction is also investigated in passive flow in an H‐type cell to produce power. This concept shows promising application to build any kind of porous electrodes with improved area utilization.