Interfacial electronic structure engineering on molybdenum sulfide for robust dual-pH hydrogen evolution

Molybdenum disulfide, as an electronic highly-adjustable catalysts material, tuning its electronic structure is crucial to enhance its intrinsic hydrogen evolution reaction (HER) activity. Nevertheless, there are yet huge challenges to the understanding and regulation of the surface electronic structure of molybdenum disulfide-based catalysts. Here we address these challenges by tuning its electronic structure of phase modulation synergistic with interfacial chemistry and defects from phosphorus or sulfur implantation, and we then successfully design and synthesize electrocatalysts with the multi-heterojunction interfaces (e.g., 1T0.81-MoS2@Ni2P), demonstrating superior HER activities and good stabilities with a small overpotentials of 38.9 and 95 mV at 10 mA/cm2, a low Tafel slopes of 41 and 42 mV/dec in acidic as well as alkaline surroundings, outperforming commercial Pt/C catalyst and other reported Mo-based catalysts. Theoretical calculation verified that the incorporation of metallic-phase and intrinsic HER-active Ni-based materials into molybdenum disulfide could effectively regulate its electronic structure for making the bandgap narrower. Additionally, X-ray absorption spectroscopy indicate that reduced nickel possesses empty orbitals, which is helpful for additional H binding ability. All these factors can decrease Mo-H bond strength, greatly improving the HER catalytic activity of these materials.

A Study of Interfacial Electronic Structure at the CuPc/CsPbI2Br Interface

In this article, CsPbI2Br perovskite thin films were spin-coated on FTO, on which CuPc was deposited by thermal evaporation. The electronic structure at the CsPbI2Br/CuPc interface was examined during the CuPc deposition by in situ X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) measurements. No downward band bending was resolved at the CsPbI2Br side, whereas there is ~0.23 eV upward band bending as well as a dipole of ~0.08 eV identified at the molecular side. Although the hole injection barrier as indicated by the energy gap from CsPbI2Br valance band maximum (VBM) to CuPc highest occupied molecular orbital (HOMO) was estimated to be ~0.26 eV, favoring hole extraction from CsPbI2Br to CuPc, the electron blocking barrier of ~0.04 eV as indicated by the offset between CsPbI2Br conduction band minimum (CBM) and CuPc lowest unoccupied molecular orbital (LUMO) is too small to efficiently block electron transfer. Therefore, the present experimental study implies that CuPc may not be a promising hole transport material for high-performance solar cells using CsPbI2Br as active layer.

Interfacial Electronic Structure Engineering on Molybdenum Sulfide for Robust Dual-pH Hydrogen Evolution

Molybdenum disulfide, as an electronic highly-adjustable catalysts material, tuning its electronic structure is crucial to enhance its intrinsic hydrogen evolution reaction (HER) activity. Nevertheless, there are yet huge challenges to the understanding and regulation of the surface electronic structure of molybdenum disulfide-based catalysts. Here we address these challenges by tuning its electronic structure of phase modulation synergistic with interfacial chemistry and defects from phosphorus or sulfur implantation, and we then successfully design and synthesize electrocatalysts with the multi-heterojunction interfaces (e.g., 1T0.81-MoS2@Ni2P), demonstrating superior HER activities and good stabilities with a small overpotentials of 38.9 and 98.5 mV at 10 mA/cm2, a low Tafel slopes of 41 and 42 mV/dec in acidic as well as alkaline surroundings, outperforming commercial Pt/C catalyst and other reported Mo-based catalysts. Theoretical calculation verified that the incorporation of metallic-phase and intrinsic HER-active Ni-based materials into molybdenum disulfide could effectively regulate its electronic structure for making the bandgap narrower. Additionally, reduced nickel possesses empty orbitals, which is helpful for additional H binding ability. All these factors can decrease Mo-H bond strength, greatly improving the HER catalytic activity of these materials.

Nitrogen-induced interfacial electronic structure with optimized water and hydrogen binding abilities for efficient alkaline hydrogen evolution electrocatalysis

Fabricating heterostructures with dense interfacial catalytic sites is vitally essential for implementation of high-performance hydrogen evolution reaction (HER). However, the strong correlation between the adsorbed hydrogen atoms and electronegative nonmetal...

Interfacial Electronic Structure Modulation Enables CoMoOx/CoOx/RuOx an Advanced Oxygen Evolution Electrocatalysis

Interface and electronic structure modulation are widely recognized as promising avenue for optimizing the physiochemical and electrochemical properties of nanomaterials, which are crucial to improving the electrocatalytic oxygen evolution reaction...

Tuning the interfacial electronic structure via Au clusters for boosting photocatalytic H2 evolution

Gold (Au) clusters are arranged at the interface of Zn0.5Cd0.5S and Mo2C, achieving (Mo2C/Au)@Zn0.5Cd0.5S configuration, where numerous Au-mediated link points can serve as multifunctional mediators for boosting photocatalytic H2 production.