Lowering Interfacial Dissolved Gas Concentration for Highly Efficient Hydrazine Oxidation at Platinum by Fluorosurfactant Modulation

Abstract

Regulating the dissolved‐gas concentration at the electrode‐solution interface represents a promising universal strategy to achieve high efficiency towards gas evolution reactions. Here, we present a facile method to modulate the interfacial dissolved‐gas concentration using cationic fluorinated pyridinium sulfonate (CFPS) for highly efficient hydrazine oxidation (HzOR). We found that the interfacial dissolved‐nitrogen concentration was effectively lowered by the cationic surfactant CFPS, while CFPS still ensured a sufficient exposure of the active sites during the HzOR. As a result, relative to pure Pt, the CFPS‐modulated Pt exhibited a 2.1‐fold higher current density and a lower overpotential for HzOR. This work presents a new avenue to achieve highly efficient hydrazine oxidation through regulating the interfacial gas concentration.

Effect of Surfactant on Electrochemically Generated Surface Nanobubbles

“…The CMC for TX-100 is 0.22–0.24 mM . This observed phenomenon is consistent with recent reports that use a fluorosurfactant to lower the interfacial gas concentration for nucleation. , …”

“…33 This observed phenomenon is consistent with recent reports that use a fluorosurfactant to lower the interfacial gas concentration for nucleation. 20,34 Classical nucleation theory predicts that the rate of bubble nucleation is highly dependent on the concentration of gas molecules present at the electrode surface. At high surface gas concentrations, it becomes thermodynamically favorable for a critical size gas nucleus to grow into a nanobubble.…”

“…Surface nanobubbles have been studied by a wide range of techniques including atomic force microscopy (AFM), dark-field microscopy, surface-plasmon resonance, and electrochemistry . Ohl and co-workers introduced a total-internal reflection fluorescence (TIRF) microscopy technique to image nanobubble formation during solvent exchange .…”

“…Surface nanobubbles have been studied by a wide range of techniques including atomic force microscopy (AFM), 18 darkfield microscopy, 19 surface-plasmon resonance, and electrochemistry. 20 reflection fluorescence (TIRF) microscopy technique to image nanobubble formation during solvent exchange. 21 This technique was recently used by the Wang group to study photocatalytic activity of single CdS nanoparticles by imaging the H 2 nanobubbles on their surfaces.…”