Interfacial Mo–N–C Bond Endowed Hydrogen Evolution Reaction on MoSe₂@N-Doped Carbon Hollow Nanoflowers

Abstract

Molybdenum diselenide (MoSe2) has been considered as promising electrocatalysts for catalyzing the hydrogen evolution reaction (HER) due to its narrow band gap and appropriate adsorption free energy. However, its catalytic performance is still impeded by inferior electrical conductivity and insufficient active sites, thus leading to unsatisfactory HER performance. Herein, MoSe2@N-doped carbon (NC) hollow nanoflowers with interfacial Mo–N–C bonds were controllably fabricated through the in situ selenization of the self-polymerized Mo–polydopamine precursor. Benefiting from the unique hollow structure, NC protective layer, and intimate interfacial interaction, the optimal MoSe2@NC displays good HER performance with low overpotentials (175 and 183 mV) and long-term stability (up to 12 h at −10 mA cm–2) in 0.5 M H2SO4 and 1.0 M KOH solutions, respectively. The theoretical results show that Mo–N–C bonds at the interface of MoSe2@NC give rise to relatively low unoccupied eg orbital density of states and ideal H2 adsorption free energy. This work presented here highlights the critical role of interfacial chemical bonds in regulating the electronic structure of nanomaterials and further improving the HER performance.

Cu–Mo Bimetal Modulated Multifunctional Carbon Nanofibers Promoting the Polysulfides Conversion for High-Sulfur-Loading Lithium–Sulfur Batteries

“…In addition, the C 1s XPS spectrum (Figure h) provides three peaks at around 284.8, 285.9, and 289.3 eV arising from CC, CN, and CN bonds, respectively, confirming that N atoms effectively doped into the carbon matrix. The N 1s XPS spectrum (Figure i) provides four signals: graphitic N (401.78 eV), pyrrolic N (400.69 eV), pyridinic N (398.75 eV), and Cu/Mo–N species (397.40 eV), respectively. , Cu, Mo nanoparticles are tightly embedded into the Cu–Mo@NPCN composite through the formation of the Cu/Mo–N bonds . The Cu 2p spectrum shows that peak of 952.4 eV is assigned to Cu 2p 1/2 , while the peak at 932.6 eV is associated with Cu 2p 3/2 (Figure j) .…”

Interfacial Chemical Bond Engineering in a Direct Z-Scheme g-C3N4/MoS2 Heterojunction

“…Both the peaks at 618 and 1130 cm −1 confirm the existence of MoS 2 (Mo−S) in the nanocomposites. 34 The absorption band near 1400 cm −1 , which was believed to be the result of the Mo−N bonds, 35,36 shows the most intense absorption for the MCN-20 sample, indicating the formation of abundant Mo−N bonds in that g-C 3 N 4 /MoS 2 nanocomposites.…”

Hierarchical Coralline-like (NiCo)S2@MoS2 Nanowire Arrays to Accelerate H2 Release for an Efficient Hydrogen Evolution Reaction

“…Density functional theory (DFT) calculations confirmed that a few proportions of the Ni atom-substituted Co site of Co 0.9 Ni 0.1 S 2 can optimize H + -adsorbed competition, hydrogen formation/desorption, and kinetics. In addition, the catalytic edge sites stemming from MoS 2 show a low Gibbs free energy for the adsorption of atomic hydrogen (Δ G H* ) like Pt-group materials . For large-scale H 2 production, water splitting is generally applied in an alkaline medium to avoid acid fog and device corrosion generated in an acidic medium.…”

“…In addition, the catalytic edge sites stemming from MoS 2 show a low Gibbs free energy for the adsorption of atomic hydrogen (ΔG H* ) like Pt-group materials. 23 For largescale H 2 production, water splitting is generally applied in an alkaline medium to avoid acid fog and device corrosion generated in an acidic medium. Nevertheless, MoS 2 shows slow kinetics in an alkaline medium.…”