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

Abstract

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.

Glycerol Is Converted into Energy and Carbonyl Compounds in a 3D-Printed Microfluidic Fuel Cell: In Situ and In Operando Bi-Modified Pt Anodes

“…This technique increases the dispersion of the NPs. 36 Finally, the porous Pt/C/CP electrodes were dried at 50 °C for 24 h and used for half-cell and cell measurements.…”

“…Thus, strips (10 × 1 mm 2 ) of CP (Toray TGP-060) were immersed in the ink and sonicated for 15 min. This technique increases the dispersion of the NPs . Finally, the porous Pt/C/CP electrodes were dried at 50 °C for 24 h and used for half-cell and cell measurements.…”

Harvesting Energy from an Organic Pollutant Model Using a New 3D-Printed Microfluidic Photo Fuel Cell

“…The catalyst in the dark shows no obvious electrochemical features but a slight increase in current at approximately −0.1 V and a reduction centered at approximately −0.45 V, which is due to the formation and reduction of Pt oxides in aqueous electrolytes. Figure A evidences detectable currents from the Pt surface, which is due to the good distribution of the 0.75%Pt-BiVO 4 powder on the high surface area CP, induced by its preparation in an ultrasonic bath …”

“…Figure 4A evidences detectable currents from the Pt surface, which is due to the good distribution of the 0.75%Pt-BiVO 4 powder on the high surface area CP, induced by its preparation in an ultrasonic bath. 45 The light induces h + on the surface of the catalyst, which partially electrooxidizes adsorbed intact or fragments of rhodamine B, leading to a net current, starting at around 0.2− 0.3 V (red curve in Figure 4A). However, the presence of CP capacitive current makes it difficult for the visualization of such current.…”

A Comprehensive Investigation of Methanol Electrooxidation on Copper Anodes: Spectroelectrochemical Insights and Energy Conversion in Microfluidic Fuel Cells

“…Here, we used the Cu NPs synthesized in an ultrasonic bath due to the high activity and efficient conversion shown in half-cell and spectroelectrochemical measurements, as discussed later. The anode was prepared by immersing a 19 mm × 1 mm CP solution in a 25 mg mL –1 Cu aqueous suspension in a sonic bath for 5 min and dried in oven at 50 °C for 6 h. This protocol developed by Caneppele et al improves particle dispersion . It is worth noting that we used Cu directly dispersed on CP instead of previously building an ink with Cu on a carbon support such as carbon black.…”