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Polymer Binder Blends Stabilize Alkaline Hydrogen Evolution by Heterogenized Molecular Phen-Based Cobalt Electrocatalysts through Coordination and Environmental Control
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Probing Terra Incognita of Ni–P Catalysts: Operando Explorations during Hydrogen Evolution Reaction
We have developed two Ni phosphide preparation methods allowing operando XAS surface-sensitive studies of well-defined bulk systems. For Ni K-edge XAS, a Ni 2 P phase-pure powder was sintered into a high-density pellet and polished for grazing incidence XAS. Ni sites were mildly affected by the acidic electrolyte prior to the HER, while the applied cathodic potential caused the reduction of Ni surface states beyond the states of as-prepared Ni 2 P. The computed fully H-covered Ni 2 P [0001] model describes the difference in the operando Ni K-edge GIXAS spectrum well. Upon turning the applied bias off, the Ni sites became immediately oxidized, forming NiO on the surface. Thus, the active phase during the HER is covalent Ni 0 close to that in the intermetallic phosphides, and Ni 2+ oxides formed after, and not during, the HER. For P K-edge XAS, Ni foam was phosphorized to form a thin Ni 3 P layer while preserving its high surface area. Upon immersion in the acidic electrolyte, the P sites underwent removal of P 5+ phosphates and formed new P coordination, possibly due to the adsorption of protons from the electrolyte. These new P surface states were not affected by turning the cathodic current on and off as soon as the sample was immersed in the acidic electrolyte. However, the removal of the sample from the electrochemical cell and drying in air resulted in substantial depletion and oxidation of surface P. Echoing the observed Ni site chemistry during HER, XAS and XPS suggest that the in situ active P sites are different from the oxidized P states observed under ex situ conditions.
Unifying the Hydrogen Evolution and Oxidation Reactions Kinetics in Base by Identifying the Catalytic Roles of Hydroxyl-Water-Cation Adducts
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Cation- and pH-Dependent Hydrogen Evolution and Oxidation Reaction Kinetics
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Silver nanoparticle enhanced metal-organic matrix with interface-engineering for efficient photocatalytic hydrogen evolution
Integrating plasmonic nanoparticles into the photoactive metal-organic matrix is highly desirable due to the plasmonic near field enhancement, complementary light absorption, and accelerated separation of photogenerated charge carriers at the junction interface. The construction of a well-defined, intimate interface is vital for efficient charge carrier separation, however, it remains a challenge in synthesis. Here we synthesize a junction bearing intimate interface, composed of plasmonic Ag nanoparticles and matrix with silver node via a facile one-step approach. The plasmonic effect of Ag nanoparticles on the matrix is visualized through electron energy loss mapping. Moreover, charge carrier transfer from the plasmonic nanoparticles to the matrix is verified through ultrafast transient absorption spectroscopy and in-situ photoelectron spectroscopy. The system delivers highly efficient visible-light photocatalytic H 2 generation, surpassing most reported metal-organic framework-based photocatalytic systems. This work sheds light on effective electronic and energy bridging between plasmonic nanoparticles and organic semiconductors.
Multi-site electrocatalysts for hydrogen evolution in neutral media by destabilization of water molecules
Abstract not provided
Edge sites dominate the hydrogen evolution reaction on platinum nanocatalysts
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The role of an interface in stabilizing reaction intermediates for hydrogen evolution in aprotic electrolytes
By combining idealized experiments with realistic quantum mechanical simulations of an interface, we investigate electroreduction reactions of HF, water and methanesulfonic acid on the single crystal (111) facets of Au, Pt, Ir and Cu in a variety of aprotic electrolytes.
Hydrogen evolution activity tuning via two-dimensional electron accumulation at buried interfaces
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Computational and experimental investigation of Co and S-doped Ni 2 P as an efficient electrocatalyst for acid mediated proton exchange membrane hydrogen evolution reaction
DFT study illuminating modification of the electronic structure and corresponding experimental validation of the enhanced acid mediated HER activity of Co and S doped Ni 2 P.
Multi-channel V-doped CoP hollow nanofibers as high-performance hydrogen evolution reaction electrocatalysts
Abstract not provided
Highly efficient electrocatalytic hydrogen evolution promoted by O–Mo–C interfaces of ultrafine β-Mo 2 C nanostructures
Ultrafine β-Mo 2 C nanostructures encapsulated in N-doped carbon capsules featuring O–Mo–C interfaces as the active sites for HER have been unveiled.
A protein scaffold enables hydrogen evolution for a Ni-bisdiphosphine complex
We find that an artificial metalloenzyme acting as a functional biomimic of hydrogenase enzymes was activated by assembly via covalent attachment of the molecular complex, [Ni(PN glycine P) 2 ] 2- , within a structured protein scaffold. Electrocatalytic H2 production was observed from pH 3.0 to 10.0 for the artificial enzyme, while no electrocatalytic activity was observed for similar [Ni(PNP) 2 ] 2+ systems.
Direct observation of bicarbonate and water reduction on gold: understanding the potential dependent proton source during hydrogen evolution
In situ VSFG measurements provide direct observation of the Au/electrolyte interface during HER in various electrolytes.
Improved high-current-density hydrogen evolution reaction kinetics on single-atom Co embedded in an order pore-structured nitrogen assembly carbon support
Single-atom metal embedded in nitrogen-doped carbon show high HER performance, with Co-NAC reaching 200 mA cm −2 at 310 mV overpotential.
Ultrafast Reaction Mechanisms in Multimolecular Ir-Co Catalytic Assemblies for Hydrogen Evolution
Nanosecond optical and X-ray spectroscopy with theoretical calculations reveal formation of a photo-induced distorted tetrahedral CoI intermediate in two Ir/Co multimolecular assemblies and show its protonation as the rate limiting step for H2 photocatalysis. Substitution of the catalysts´ pyridine group on the para position by -COOEt improves the protonation efficiency.
Green synthesis of ultrathin WS 2 nanosheets for efficient hydrogen evolution reaction
The synthesis of ultrathin WS 2 nanosheets and HAADF-STEM image highlighting the defect areas (edge defects and S line vacancies).