Janus MoSi₂P₂As₂ Decorated with Transition Metal Atoms as Efficient Bifunctional HER/OER and OER/ORR Electrocatalysts

It is of great importance to develop bifunctional electrocatalysts with high efficiency and low cost for water splitting and fuel cells. Herein, based on the new emerging two-dimensional material of MoSi₂N₄, we explore the potentials of novel Janus MoSi₂P₂As₂ (labeled as MSPA) in electrocatalytic applications. We conduct a comprehensive study using first-principles calculations to explore the potential of Janus MoSi₂P₂As₂ decorated with 13 kinds of transition metal atoms as efficient bifunctional catalysts for the hydrogen/oxygen evolution reaction (HER/OER) and oxygen evolution/reduction reaction (OER/ORR). After screening, results show that Rh@MSPA and Au@MSPA can serve as bifunctional catalysts for OER/ORR with overpotentials of 0.27/0.29 V and 0.42/0.37 V, and Pt@MSPA exhibit great potential as HER/OER catalyst with an overpotential of -0.004/0.51 V. The solvation effect on catalytic activity is also investigated. The volcano diagrams are employed to depict the activity trends toward HER, OER, and ORR. The d-band center, ICOHP and intrinsic descriptor φ can serve as quantitative descriptors of ORR/OER activity and reveal the activity origin of OER/ORR. This study presents a viable approach for developing advanced electrocatalysts with multiple functionalities, thereby expanding the utilization of Janus MoSi₂P₂As₂ in electrocatalysis.