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Electrochemically Lighting Up Luminophores at Similar Low Triggering Potentials with Mechanistic Insights
journal contribution
posted on 2020-04-01, 19:09 authored by Li Fu, Bin Zhang, Kena Fu, Xuwen Gao, Guizheng ZouElectrochemiluminescence
(ECL) with high electrode compatibility
and less electrochemical interference has conventionally been envisioned
by lowering the oxidative potential of luminophores and/or screening
luminophores with a low oxidative potential. Herein, an alternative
was developed by employing the environmental-friendly carbohydrazide
as a coreactant, which enabled serial luminophores with oxidative-reduction
ECL at one similar low triggering potential around 0.55 V versus
Ag/AgCl, including Ru(bpy)32+ as well as CdTe,
CdSe, CuInS2/ZnS, and Au nanocrystals. Because the eight-electron
releasing process of carbohydrazide was electrochemically triggered
at ∼0.25 V versus Ag/AgCl, the radicals generated via electrochemical
oxidation of carbohydrazide could reduce the luminophores at a much
lower potential than those of traditional coreactants. All the luminophore/carbohydrazide
systems exhibited one ECL process around 0.55 V, which was about 0.65
V lower than that of a traditional Ru(bpy)32+/tri-n-propylamine system (typically around +1.2
V), and even lower than the oxidative potential of some luminophores.
The ECL of the luminophore/carbohydrazide system was spectrally close
to that of the corresponding luminophore/tri-n-propylamine
system; the maximum emission wavelength of the low triggering potential
ECL could shift from 540 to 783 nm via the selection of luminophores
in this case. The coreactant screening strategy would be a favorable
addition to the expected luminophore screening strategy for achieving
enhanced ECL performance. This work created an avenue toward a deeper
understanding of the ECL mechanism.