Dataset Information

Highly Efficient Oxygen Evolution Reaction Enabled by Phosphorus Doping of the Fe Electronic Structure in Iron-Nickel Selenide Nanosheets.

ABSTRACT: The electronic structure of active sites is critically important for electrochemical reactions. Here, the authors report a facile approach to independently regulate the electronic structure of Fe in Ni_0.75 Fe_0.25 Se₂ by P doping. The resulting electrode exhibits superior catalytic performance for the oxygen evolution reaction (OER) showing a low overpotential (238 mV at 100 mA cm^-2 , 185 mV at 10 mA cm^-2 ) and an impressive durability in an alkaline medium. Additionally, the mass activity of 328.19 A g^-1 and turnover frequency (TOF) of 0.18 s^-1 at an overpotential of 500 mV are obtained for P─Ni_0.75 Fe_0.25 Se₂ which is much higher than that of Ni_0.75 Fe_0.25 Se₂ and RuO₂ . This work presents a new strategy for the rational design of efficient electrocatalysts for OER.

SUBMITTER: Huang Y

PROVIDER: S-EPMC8456200 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Nitrogen doping has been always regarded as one of the major factors responsible for the increased catalytic activity of Fe-N-C catalysts in the oxygen reduction reaction, and recently, sulfur has emerged as a co-doping element capable of increasing the catalytic activity even more because of electronic effects, which modify the d-band center of the Fe-N-C catalysts or because of its capability to increase the Fe-Nx site density (SD). Herein, we investigate in detail the effect of sulfur doping of carbon support on the Fe-Nx site formation and on the textural properties (micro- and mesopore surface area and volume) in the resulting Fe-N-C catalysts. The Fe-N-C catalysts were prepared from mesoporous carbon with tunable sulfur doping (0-16 wt %), which was achieved by the modulation of the relative amount of sucrose/dibenzothiophene precursors. The carbon with the highest sulfur content was also activated through steam treatment at 800 °C for different durations, which allowed us to modulate the carbon pore volume and surface area (1296-1726 m2 g-1). The resulting catalysts were tested in O2-saturated 0.5 M H2SO4 electrolyte, and the site density (SD) was determined using the NO-stripping technique. Here, we demonstrate that sulfur doping has a porogenic effect increasing the microporosity of the carbon support, and it also facilitates the nitrogen fixation on the carbon support as well as the formation of Fe-Nx sites. It was found that the Fe-N-C catalytic activity [E1/2 ranges between 0.609 and 0.731 V vs reversible hydrogen electrode (RHE)] does not directly depend on sulfur content, but rather on the microporous surface and therefore any electronic effect appears not to be determinant as confirmed by X-ray photoemission spectroscopy (XPS). The graph reporting Fe-Nx SD versus sulfur content assumes a volcano-like shape, where the maximum value is obtained for a sulfur/iron ratio close to 18, i.e., a too high or too low sulfur doping has a detrimental effect on Fe-Nx formation. However, it was highlighted that the increase of Fe-Nx SD is a necessary but not sufficient condition for increasing the catalytic activity of the material, unless the textural properties are also optimized, i.e., there must be an optimized hierarchical porosity that facilitates the mass transport to the active sites.

Dataset Information

Highly Efficient Oxygen Evolution Reaction Enabled by Phosphorus Doping of the Fe Electronic Structure in Iron-Nickel Selenide Nanosheets.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure