M₄B₆X₆ as a New Family of High‐Efficient Electrocatalysts: The Role of Surface Reconstruction in Water Oxidization

Abstract

Searching for highly-efficient electrocatalysts for water splitting has been greatly endowed due to the huge demand for green energy sources. Two-dimensional (2D) materials are widely explored for the purpose because of their unique physical and chemical properties, abundant active sites, and easy fabrication.Here, we present a new family of 2D M 4 B 6 X 6 (2D Boridenes) and investigate their physical and chemical properties for their potential applications into electrocatalysis based on firstprinciples calculations. We demonstrate that 2D M 4 B 6 X 6 (M = Cr, Mo, and W; X = O and F) are dynamically, thermodynamically, and mechanically stable, and show intriguing electronic and catalytic properties. Importantly, we find that M 4 B 6 O 6 are intrinsically active for oxygen evolution reaction (OER). Our results demonstrate that: (1) the adsorbate-escape mechanism dominates the OER process with a low overpotential of 0.652 V on Cr 4 B 6 O 6 ; (2) the partial surface-oxidization can improve the catalytic performance of M 4 B 6 F 6 dramatically; and (3) the surface reconstruction greatly affects the OER performance of M 4 B 6 X 6 . Our findings illustrate that the surface reconstruction is critical to the OER activity, which may provide a new strategy on the design of 2D materials for electrocatalysis and offer theoretical insight into the catalytic mechanism.

Two-dimensional Janus perovskite oxynitrides as active photocatalysts for overall water splitting with ferroelectric modulation

“…The OER process involves a complicated four-electron reaction with the formation of *OH, *O, and *OOH intermediates successively. 63 The catalytic activity of the OER can be predicted by the potential-determining step (PDS), which is the largest Δ G in the four-step reaction (details in Method). 53 For 2D BaNbNO 2 , the calculated Δ G values show that the reaction energies for the first three steps in the OER process are quite uniform, indicating that the energy barrier should be low, and the last step is exothermic, indicating that the oxygen molecules are prone to be released.…”

A review on defect modulated electrocatalysts for the oxygen evolution reaction

“…Similar conclusions that defects can guide structural reconstruction to enhance the catalytic properties have also been mentioned in many previous reports. 36,96–98…”