High-Throughput Screening of Atomic Defects in MXenes for CO₂ Capture, Activation, and Dissociation

Abstract

The capture, activation, and dissociation of carbon dioxide (CO2) is of fundamental interest to overcome the ramifications of the greenhouse effect. In this regard, high-throughput screening of two-dimensional MXenes has been examined using well-resolved first-principles simulations through DFT-D3 dispersion correction. We systematically investigated different types of structural defects to understand their influence on the performance of M2X-type MXenes. Defect calculations demonstrate that the formation of M2C­(VMC) and M2N­(VMN) vacancies require higher energy, while M2C­(VC) and M2N­(VN) vacancies are favorable to form during the synthesis of M2X-type MXenes. The M2X-type MXenes from group III to VII series show remarkable behavior for active capturing of CO2, especially group IV (Ti2X and Zr2X) MXenes exhibit unprecedentedly high adsorption energies and charge transfer (>2e) from M2X to CO2. The potential CO2 capture, activation, and dissociation abilities of MXenes are emanated from Dewar interactions involving hybridization between π orbitals of CO2 and metal d-orbitals. Our high-throughput screening demonstrates chemisorption of CO2 on pure and defective MXenes, followed by dissociation into CO and O species.

Mechanistic insights for electrochemical reduction of CO2 into hydrocarbon fuels over O-terminated MXenes

“…In our recent work, 76 we performed high-throughput screening to understand the CO 2 capture and activation mechanism over a series of bare and defective M 2 X-type MXenes. We observed remarkably high adsorption energies and charge transfer from group IV (Ti 2 X and Zr 2 X) MXenes to CO 2 molecules, followed by dissociation into CO and O species.…”

A strategic review of MXenes as emergent building blocks for future two-dimensional materials: recent progress and perspectives

“…On the other hand, the perfect sites interact nonspontaneously with CO 2 via an endothermic process. 245 Our recent studies 264 on defective MXenes demonstrate unprecedented high adsorption energies and charge transfer from M 2 X to CO 2 for group IV based M 2 X systems as shown in Fig. 8f-i.…”

Surface engineering of MXenes for energy and environmental applications

“…Singh et al 205 systematically screened the different types of atomic defects on M 2 X-type MXenes. They found that higher energy was required for the formation of M 2 C(V MC ) and M 2 N(V MN ) vacancies, while the formation of the M 2 C(V C ) and M 2 N(V N ) vacancies is preferable on M 2 X-type MXenes, as shown in Fig.…”