The activity of Pd supported Pd supported SiX (X=Group-V) Single-atom catalysts for hydrogen evolution reaction.

Developing a low-cost, durable, high-performance single-atom catalyst (SAC), active for hydrogen evolution reaction (HER), is an effective strategy for energy applications. Herein, we have investigated the structural, electronic and HER catalytic activity of palladium-decorated SiX (X = Group-V) SACs within the density functional theory (DFT) framework. Strong interaction between the palladium atom and SiX nanosheets is observed, as evident from the negative value of binding energy and Bader charge transfer. Palladium modifies the electronic properties of SiX nanosheets, reducing the band gap of Pd@SiX SACs. It is observed that the Gibbs free energy (ΔG) for Pd@SiX SACs decreases as compared to pristine systems. But under the external potential the photogenerated electrons provide at pH=0, Pd@SiSb and Pd@SiBi indicate an ΔG of 0.23 and -0.22 eV, respectively. At pH=7, the best catalytic activity is shown by Pd@SiBi with a ΔG of 0.19 eV, making it active towards HER activity. This indicates the potential application of Pd@SiBi towards HER activity in the pH=0 to 7 and under the supplied external potential. Our findings may provide fruitful insights into designing and fabricating low-dimensional materials using SAC as palladium for enhanced catalytic activities.