Vacancy‐Induced Oxygen Reduction Activity in Janus Transition Metal Dichalcogenides

Abstract

In the past few years, transition metal dichalcogenides (TMDs) have attracted extensive attention in the development of oxygen reduction reaction (ORR) catalysts. Herein, a new family of TMDs, Janus TMDs, as ORR catalyst has been investigated by employing the density functional methods. Our results indicated that the pristine Janus TMDs (MoXY, X, Y=S, Se, Te; X≠Y) and MoXY with X vacancy have poor ORR activity. In contrast, MoXY with Mo vacancy, i. e., MoXY‐SV‐Mo are good ORR catalysts due to the moderate adsorption strength of the ORR intermediates. In particular, MoSeS‐SV‐Mo possess the highest ORR activity with a low overpotential of 0.51 V. In addition, the ORR activity is slightly improved under tensile strain, while the compressive strain reduces the ORR activity. These results demonstrated that creating Mo vacancy in MoXY can modulate the ORR activity of Janus TMDs effectively.

Dicarbon nitride and Janus transition metal chalcogenides van der Waals heterojunctions for photocatalytic water splitting

“…Due to the difference in subversion between atoms, Mo and chalcogenide elements form three kinds of sulfides MoSeS, MoSTe, and MoSeTe with different lattice constants. After structural optimization, the lattice constants of isolated monolayer MoSeS, MoSTe, and MoSeTe are a = b = 3.215 Å, 3.323 Å, and 3.391 Å, respectively, which is consistent with previous works [50,51]. The structure of MoSeS as a prototype is given in figure 1(b).…”

Recent advances in low-dimensional Janus materials: theoretical and simulation perspectives

“…It has been reported that the excellent catalytic activity of TMDs can be mainly attributed to the vacancies, edge sites, doping, impurities, and grain boundaries. [29,114,115] Er et al [50] found that the recently synthesized family of Janus TMDs can be promising candidates for the HER due to the inherent structural asymmetry. They specifically identified Janus WSSe monolayer as a promising candidate since its basal plane can be activated without large applied tensile strains and in the absence of a significant density of vacancies.…”

Electrical, optical and mechanical properties of monolayer MoTe2 for applications in wearable optoelectronic devices

“…The presence of a chalcogen vacancy can effectively decrease the interfacial distance between the metal and transition metal dichalcogenide (TMD), thereby reducing both the tunnel barrier and contact resistance [20]. Mo vacancy in MoXY (Y = S, Se, Te; X not equal Y) can effectively modulate the ORR activity of Janus TMDs [21]. Lastly, a dopant-induced modification can influence the optical and magnetic properties of TMDs [22].…”