Simultaneously Realizing Rapid Electron Transfer and Mass Transport in Jellyfish‐Like Mott–Schottky Nanoreactors for Oxygen Reduction Reaction

Abstract

Fundamental understanding of constructing elevated catalysts to realize fast electron transfer and rapid mass transport in oxygen reduction reaction (ORR) chemistry by interface regulation and structure design is important but still ambiguous. Herein, a novel jellyfish-like Mott-Schottkytype electrocatalyst is developed to realize fast electron transfer and decipher the structure-mass transport connection during ORR process. Both spectroscopy techniques and density functional theory calculation demonstrate electrons spontaneously transfer from Fe to N-doped graphited carbon at the heterojunction interface, thus accelerating electron transfer from electrode to reactant. Dynamic analysis indicates unique structure can significantly improve mass transport of oxygen-species due to two factors: one is electrolyte streaming effect caused by tentacle-like carbon nanotubes; the other is effective collision probability in the semiclosed cavity. Therefore, this Mott-Schottky-type catalyst delievers superior ORR performance with high onset potential, positive half wave potential, and large current density. It also exhibits low overpotential when serving as an air cathode in Zn-air batteries. This work deepens understanding of the two key factors-electron transfer and mass transport-on determining the kinetic reaction of ORR process and offers a new avenue in constructing efficient Mott-Schottky electrocatalysts.

Tuning the Fe–N4 sites by introducing Bi–O bonds in a Fe–N–C system for promoting the oxygen reduction reaction

“…2c, the state of elemental Bi in Fe/Bi-RNC is shown in the high-resolution Bi 4f XPS, which can be divided into Bi 4f 7/2 (159.0 ± 0.1 eV) and Bi 4f 5/2 (164.3 ± 0.1 eV), indicating that Bi is bound to O in the carbon structure. 39,40 Meanwhile, FTIR spectra also confirm the presence of Bi–O bonds in Fe/Bi-RNC with the vibration peaks located around 560 cm −1 and 850–900 cm −1 (Fig. S6†).…”

Steel Mesh Reinforced Ni(OH)2 Nanosheets with Enhanced Oxygen Evolution Reaction Performance

“…[20,30] The smaller diameter of the semicircle of the low-frequency curve, the faster charge transfer in the electrode, that is, the lower the charge transfer resistance (Rct). [21,31] Intermediate are easier to form, which increases the kinetic reaction rate to a certain extent, so the catalytic activity is also higher. [22] The EIS curves of obtained samples were shown in Fig.…”

Metal-Supported Biochar Catalysts for Sustainable Biorefinery, Electrocatalysis, and Energy Storage Applications: A Review

“…The metal sulfides were loaded on the biomass source before carbonization at 900 • C (2 h, N 2 atmosphere) using NaSCN, FeCl 3 , ZnCl 2 , and 2,2-bipyridine as reactants. HR-TEM and Mott-Schottky results indicated the formation of numerous FeS/ZnS heterojunctions, which reportedly have the effect of increasing the electron transfer rate [179,187] and enhancing the absorption capacity of O 2 molecules [186]. Furthermore, as both metal sulfides are semiconductors and heterojunctions are photo-responsive, the catalytic properties of the material can be enhanced via light irradiation.…”