Two-dimensional boron: Lightest catalyst for hydrogen and oxygen evolution reaction

Abstract

The hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) have been envisaged on a two-dimensional (2D) boron sheet through electronic structure calculations based on a density functional theory framework. To date, boron sheets are the lightest 2D material and, therefore, exploring the catalytic activity of such a monolayer system would be quite intuitive both from fundamental and application perspectives. We have functionalized the boron sheet (BS) with different elemental dopants like carbon, nitrogen, phosphorous, sulphur, and lithium and determined the adsorption energy for each case while hydrogen and oxygen are on top of the doping site of the boron sheet. The free energy calculated from the individual adsorption energy for each functionalized BS subsequently guides us to predict which case of functionalization serves better for the HER or the OER.

Density Functional Theory Study of Aspirin Adsorption on BCN Sheets and their Hydrogen Evolution Reaction Activity: a Comparative Study with Graphene and Hexagonal Boron Nitride

“…In a recent study, Ba et al experimentally synthesized such type of sheets where they trimmed down the band gap of h-BN sheet to � 2 eV which is about 1/3 of pristine sheet. [41] Now, considering the influence of ASA on the band gap of GRAP, BCN, and h-BN, we found that ASA adsorbed GRAP and BCN sheet do not show any change in the band structure, as the ASA flat bands occur deep in the conduction and valence band. A negligibly small increase of 9 meV (11 meV) in the band gap was seen in ASA adsorbed BCN1 (BCN2) for C1 configuration.…”

“…In a recent study, Ba et al. experimentally synthesized such type of sheets where they trimmed down the band gap of h‐BN sheet to ≈2 eV which is about 1/3 of pristine sheet …”

The interaction of halogen atoms and molecules with borophene

“…23 These novel properties make borophene an ideal candidate for various applications. 9 Ab initio studies predicted that doped borophene can be used as a catalyst for hydrogen and oxygen evolution reactions, 24 is a promising anode material for lithium-ion batteries, 25,26 and is a potential hydrogen storage medium. 27 Boronbased microelectronic device applications is an another interesting field, however, the implementation of borophene requires further investigation.…”

Theoretical Evidence behind Bifunctional Catalytic Activity in Pristine and Functionalized Al2C Monolayers

“…The free energy of the adsorbed hydrogen is defined as DG H* ¼ E ads þ DE ZPE À TDS H (H* is the adsorbed phase of hydrogen on the surface), where E ads is the adsorption energy of hydrogen and DE ZPE is the zero point energy (ZPE) difference of H 2 in adsorbed and gas state, which is around 0.04 eV. [23][24][25] The entropic contribution differencef or the adsorbed hydrogen is the third term of the equation,w hichgives rise to ac orrection value of 0.2 eV under the experimental conditions. The adsorption entropy DS H %À 1 2 DS 0 H assuming the vibrational entropy is small in the adsorbed state with DS 0 H is the entropy of H 2 in gas phase.T he free energy corresponding to the adsorp- Table 1.…”