2 research outputs found
Enhanced Hydrogen Purification in Nanoporous Phosphorene Membrane with Applied Electric Field
As
a feasibility study for hydrogen purification, the mechanisms
of H<sub>2</sub>, CO<sub>2</sub>, N<sub>2</sub>, CO, and CH<sub>4</sub> penetrating through self-passivated porous phosphorene membranes
with different pore sizes were systematically investigated by density
functional theory. The thermal stability of porous phosphorene membranes
with various pore sizes was studied by <i>ab initio</i> molecular
dynamics. By applying an external electric field perpendicular to
the porous phosphorene membrane, the diffusion of CO<sub>2</sub> and
N<sub>2</sub> through the pores was remarkably suppressed due to the
polarizability of these molecules, whereas the energy barrier and
permeance of H<sub>2</sub> passing through the membrane is virtually
unaffected. Thus, the application of the electric field improves the
performance of hydrogen purification further. This finding opens up
a new avenue to optimally tune the performance of 2D materials for
gas separation by applying an external electric field
Label-Free LSPR Detection of Trace Lead(II) Ions in Drinking Water by Synthetic Poly(mPD-<i>co</i>-ASA) Nanoparticles on Gold Nanoislands
Using self-assembly
gold nanoislands (SAM-AuNIs) functionalized
by poly(<i>m</i>-phenylenediamine-<i>co</i>-aniline-2-sulfonic
acid) (poly(mPD-<i>co</i>-ASA)) copolymer nanoparticles
as specific receptors, a highly sensitive localized surface plasmon
resonance (LSPR) optochemical sensor is demonstrated for detection
of trace lead cation (Pb(II)) in drinking water. The copolymer receptor
is optimized in three aspects: (1) mole ratio of mPD:ASA monomers,
(2) size of copolymer nanoparticles, and (3) surface density of the
copolymer. It is shown that the 95:5 (mPD:ASA mole ratio) copolymer
with size less than 100 nm exhibits the best Pb(II)-sensing performance,
and the 200 times diluted standard copolymer solution contributes
to the most effective functionalization protocol. The resulting poly(mPD-<i>co</i>-ASA)-functionalized LSPR sensor attains the detection
limit to 0.011 ppb toward Pb(II) in drinking water, and the linear
dynamic range covers 0.011 to 5000 ppb (i.e., 6 orders of magnitude).
In addition, the sensing system exhibits robust selectivity to Pb(II)
in the presence of other metallic cations as well as common anions.
The proposed functional copolymer functionalized on AuNIs is found
to provide excellent Pb(II)-sensing performance using simple LSPR
instrumentation for rapid drinking-water inspection