Exploring the catalytic properties of Ti2CO2 MXene decorated with Cu-cluster for Hydrogen evolution reaction

Catalysts based on non-noble and cost-effective metals are crucial for the hydrogen evolution reaction (HER) to obtain a viable source of renewable energy in the form of hydrogen. MXene is one of the 2D materials that has recently drawn much interest due to its intriguing catalytic properties. In this work, employing density functional theory we have systematically studied and compared the HER activity of Ti2CO2 MXene with adsorbed Cu3 and Cu5 clusters on top. Our findings suggest that the Ti2CO2 MXene with adsorbed Cu3 cluster exhibits significant enhancement in catalytic activity towards HER. The Gibbs free energy of hydrogen adsorption (= GH*) is found to be -0.08 eV, which is close to the ideal value, suggesting comparable catalytic activity to platinum. In contrast, the Ti2CO2-Cu5 catalyst exhibits a higher Gibbs free energy value of 0.105 eV for HER. The stability of the structures was evaluated by assessing the cohesive and binding energies, supported by Ab Initio Molecular Dynamics (AIMD) simulations. A thorough analysis of the electronic structure and bonding nature of the catalysts are presented. These analyses suggest that the boost in catalytic activity could be ascribed to the accumulated charge at the centre of the Cu3 cluster. Based on our comparison, the Ti2CO2-Cu3 catalyst emerges as a more suitable candidate for the HER process, highlighting its potential as a cost-effective and efficient HER catalyst.