Doping-Induced Enhancement of Hydrogen Evolution at MoS Electrodes.

Rate theory and DFT calculations of hydrogen evolution reaction (HER) on MoS with Co, Ni and Pt impurities show the significance of dihydrogen (H*) complex where both hydrogen atoms are interacting with the surface. Stabilization of such a complex affects the competing Volmer-Heyrovsky (direct H release) and Volmer-Tafel (H* intermediate) pathways. The resulting evolution proceeds with a very small overpotential for all dopants ( =0.

Hydrogen evolution descriptors of 55-atom PtNi nanoclusters and interaction with graphite.

Density functional simulations have been performed for PtNi55-nclusters (n=0,12,20,28,42,55) to investigate their catalytic properties for the hydrogen evolution reaction (HER). Starting from the icosahedralPt12Ni43, hydrogen adsorption energetics and electronic-band descriptors indicate HER activity comparable to that of purePt55(distorted reduced core structure). The PtNi clusters accommodate a large number of adsorbed hydrogen before reaching a saturated coverage, corresponding to 3-4 H atoms per icosahedron facet (in total ∼70-80).

Three in One: Three Different Molybdates Trapped in a Thiacalix[4]arene Protected Ag Nanocluster for Structural Transformation and Photothermal Conversion.

Polyoxometalates (POMs) represent crucial intermediates in the formation of insoluble metal oxides from soluble metal ions, however, the rapid hydrolysis-condensation kinetics of Mo or W makes the direct characterization of coexisted molecular species in a given medium extremely difficult. Silver nanoclusters have shown versatile capacity to encapsulate diverse POMs, which provides an alternative scene to appreciate landscape of POMs in atomic precision. Here, we report a thiacalix[4]arene protected silver nanocluster (Ag72b) that simultaneously encapsulates three kinds of molybdates (MoO , Mo O and Mo O ) in situ transformed from classic Lindqvist Mo O , providing more deep understanding on the structural diversity and condensation growth route of POMs in solution.

Sulfur-deficient edges as active sites for hydrogen evolution on MoS.

A grand-canonical approach is employed to calculate the voltage-dependent activation energy and estimate the kinetics of the hydrogen evolution reaction (HER) on intrinsic sites of MoS, including edges of varying S-coverage as well as S-vacancies on the basal plane. Certain edge configurations are found to be vastly more active than others, namely S-deficient edges on the Mo-termination where, in the fully S-depleted case, HER can proceed with activation energy below 0.5 eV at an electrode potential of 0 V SHE.