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[Display omitted] • Reactions of bis(cyclopentadienyl) ruthenium (ruthenocene, RuCp 2) and cyclopentadienyl pyrrolyl ruthenium (RuCpPy) on the hydroxylated surface were explored by density functional theory calculations. • Ru precursors, such as bis(pyrrolyl) ruthenium (RuPy 2), were designed for H 2 O-based atomic layer deposition of RuO 2 · x H 2 O. • New cascade mechanism of H 2 O-based atomic layer deposition of RuO 2 · x H 2 O was proposed. As the unique nanofabrication technique, atomic layer deposition (ALD) can be used to deposit high-quality, uniform, and conformal nanoparticle coatings. Ru and its oxides (RuO x) are important materials in the fields of microelectronics and catalysis. In this work, the reaction of Ru precursors with different ligands on the hydroxylated surfaces were explored. The elimination of the pyrrolyl (Py) ligand is easier than that of the cyclopentadienyl (Py) ligand on the hydroxylated surface. The reaction involved in RuO 2 · x H 2 O ALD using RuPy 2 and H 2 O as precursors was further investigated. During the RuPy 2 reaction, the pyrrolyl ligand is eliminated by the substitution reaction with a surface hydroxyl group. However, the desorption of the pyrrole molecule is difficult due to the strong adsorption between the pyrrole molecule and Ru surface. During the H 2 O reaction, the H 2 O molecules further help the elimination of pyrrolyl ligands from the surface and the dissociative desorption of pyrrole molecules This unique reaction mechanism involved in the ALD of RuO 2 with the assistance of H 2 O can be termed new cascade mechanism. These findings provide theoretical guidance for precursor design and ALD growth of metal oxides. [ABSTRACT FROM AUTHOR]

Abstract Despite their high theoretical capacity, the practical commercialization of lithium-sulfur batteries have continued to face obstacles of low cycle stability and low efficiency, which stem from the dissolution and diffusion of lithium polysulfides intermediates in the electrolyte. Here, by means of comprehensive density functional theory computations, we exploited the potentials of the experimentally available metal-nitrogen/graphene as the anchoring material for high-performance Li-S batteries. Our results revealed that Cr-, Mn-, Fe-, Co-, and Cu-nitrogen/graphenes exhibit optimal interaction with soluble lithium polysulfides due to the synergistic effects between the metal and N atoms, which not only effectively traps the soluble lithium polysulfides to suppress the shuttle effects, but also well keeps their cyclic structures intact. Especially, the electronic properties of metal-nitrogen/graphenes are well preserved, and the computed voltages of discharge processes are larger than those of the well-established nitrogen-doped graphenes. Thus, the metal-nitrogen/graphene could present a kind of quite promising anchoring material for lithium sulfur battery cathodes to suppress the lithium polysulfides shuttle effect. Graphical abstract Unlabelled Image Highlights • Metal-N 4 /graphene restrains the shuttle effect via remarkable (but not strong) binding strength with Li 2 S n species. • The intactness of Li 2 S n species is well preserved after adsorption on metal-N 4 /graphene. • The conductance of metal-N 4 /graphene is nearly unchanged after adsorption of Li 2 S n species. • The computed voltages of discharge processes are larger than those of well-established N-doped graphenes. [ABSTRACT FROM AUTHOR]