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First-principles calculations for metal−phthalocyanines (MPc, M = Co, Fe, H 2 ) adsorbed on Au(111) surfaces with LDA, PW91, and optB86b-vdW functionals are performed. The adsorption energies, adsorption distances, potential energy surfaces, electron transfer properties, and the migration barriers are calculated and compared with the reported experimental data. Our results show that, while PW91 functional is obviously not suitable for MPc/Au(111) systems due to its intrinsic short comings, LDA and optB86b-vdW functionals give more reliable results. The optB86b-vdW functional has overall the best performance among the three functionals, which indicates that the van der Waals interactions play key roles in such adsorption systems.

Magnetic moment orientations of α-Fe nanowire arrays with two different diameters have been investigated by means of transmission Mössbauer spectroscopy (MS) and conversion electron Mössbauer spectroscopy (CEMS). From the intensity ratio in the sextets of MS and CEMS, it is found that inside the α-Fe nanowire array (60 nm in diameter) the magnetic moments are well parallel to the nanowires, but near the extremities of the nanowires the magnetic moment orientation deviates from parallelism to the long axis of the wire. When the diameter of the α-Fe nanowires increases (300 nm in diameter), CEM spectra indicate that the mean angle of orientation between the moment direction and the long axis of the wire becomes larger near the extremities of the nanowires. The calculated configurations of magnetic moment orientations are consistent with the MS and CEMS measurements.

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Molybdenum disulfide (MoS 2 ) has been regarded as one of the most promising candidates for replacing Pt group noble metals as an efficient electrocatalyst to enhance the hydrogen evolution reaction (HER) in consideration of its relatively high earth abundance. Recent studies show that the catalytic efficiency of MoS 2 for HER can be promoted by the presence of 1T-phase MoS 2 . It is hard to precisely control the formation of 1T-MoS 2 , however, due to its metastability relative to 2H-MoS 2 . Elevating the stability of 1T phase allotrope is therefore of great importance and could be realized by replacing divalent S with monovalent elements or groups according to crystal field theory, which has been demonstrated through our firstprinciples density functional theory (DFT) calculation results. Differential Gibbs free energy analysis for hydrogen adsorption (ΔG H* ) suggest that 1T and 1T' MoSO (O doped MoS 2 ) might be taken as potential candidate catalysts for HER process with better performance than 1T and 1T' MoS 2 . We also propose a probable approach to synthesize 1T and 1T' MoSO under oxidation circumstance environment of graphene oxide.