4 research outputs found
Pyrolyzing soft template-containing poly(ionic liquid) into hierarchical N-doped porous carbon for electroreduction of carbon dioxide
Heteroatom-doped carbon materials have demonstrated great potential in the electrochemical reduction reaction of CO2 (CO2RR) due to their versatile structure and function. However, rational structure control remains one challenge. In this work, we reported a unique carbon precursor of soft template-containing porous poly(ionic liquid) (PIL) that was directly synthesized via free-radical self-polymerization of ionic liquid monomer in a soft template route. Variation of the carbonization temperature in a direct pyrolysis process without any additive yielded a series of carbon materials with facile adjustable textural properties and N species. Significantly, the integration of soft-template in the PIL precursor led to the formation of hierarchical porous carbon material with a higher surface area and larger pore size than that from the template-free precursor. In CO2RR to CO, the champion catalyst gave a Faraday efficiency of 83.0% and a current density of 1.79 mA?cm?2 at ?0.9 V vs. reversible hydrogen electrode (vs. RHE). The abundant graphite N species and hierarchical pore structure, especially the unique hierarchical small-/ultra-micropores were revealed to enable better CO2RR performance
Holographic detection of parity in atomic and molecular orbitals
We introduce a novel and concise methodology to detect the parity of atomic
and molecular orbitals based on photoelectron holography, which is more general
than the existing schemes. It fully accounts for the Coulomb distortions of
electron trajectories, does not require sculpted fields to retrieve phase
information and, in principle, is applicable to a broad range of electron
momenta. By comparatively measuring the differential photoelectron spectra from
strong-field ionization of N molecules and their companion atoms of Ar,
some photoelectron holography patterns are found to be dephased for both
targets. This is well reproduced by the full-dimensional time-dependent
Schr\"{o}dinger equation and the Coulomb quantum-orbit strong-field
approximation (CQSFA) simulation. Using the CQSFA, we trace back our
observations to different parities of the 3 orbital of Ar and the
highest-occupied molecular orbital of N via interfering Coulomb-distorted
quantum orbits carrying different initial phases. This method could in
principle be used to extract bound-state phases from any holographic structure,
with a wide range of potential applications in recollision physics and
spectroscopy