Theoretical Evidence behind Bifunctional Catalytic Activity in Pristine and Functionalized Al 2 C Monolayers.

First principles electronic structure calculations based on the density functional theory (DFT) framework are performed to investigate hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) on two-dimensional Al2 C monolayers. In addition to the pristine Al2 C monolayer, monolayers doped with Nitrogen (N), Phosphorous (P), Boron (B), and Sulphur (S) are also investigated. After determining the individual adsorption energy of hydrogen and oxygen on the different functionalized Al2 C monolayers, the adsorption free energies are predicted for each of the functionalized monolayers in order to assess their suitability for HER or OER. The density of states and optical absorption spectra calculations along with the work function of the functionalized Al2 C monolayers enable us to gain a profound understanding of the electronic structure for the individual system and their relation to the water splitting mechanism.