Calculation screening of Janus WSSe monolayer modified with single platinum group metal atom as efficient bifunctional oxygen electrocatalysts

Developing cost-effective bifunctional electrocatalysts is eagerly desirable for electrochemical energy applications. Herein, using the first-principles computations, the structural, electronic, magnetic, oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalytic properties of single platinum group metal (PGM) atom modified Janus WSSe monolayer systems are comprehensively investigated. The results reveal that the single PGM atom can be stably supported on the W top position of S side and effectively regulate the structural and electronic characteristics of Janus WSSe monolayer. Pd- and Pt-WSSe are effectively screened from the PGM-WSSe systems with the outstanding bifunctional catalytic activity elucidated, especially the Pd-WSSe exhibits even smaller overpotentials (ηORR ≈ 0.39 and ηOER ≈ 0.49 V). The mechanisms of prominent bifunctional catalytic activity of Pd- and Pt-WSSe are summarized including their moderate binding strength with O2 molecule, superior electrical conductivity, high intrinsic electric field and the d orbital occupancy of Pd and Pt atoms. Thus, the effective strategy to reduce the dosage of PGMs in PGM single atom catalysts (SACs) and to boost the bifunctional catalytic performance of Janus WSSe monolayer could be achieved, which would be useful to promote the exploration of novel bifunctional electrocatalysts.